Presented at the 40th International Conference on Software Engineering, May 27 - 3 June 2018, Gothenburg, Sweden (ICSE 2018) as Journal first publication.

1. Augmenting and structuring user queries to
support efficient free-form code search
Raphael Sirres1, Tegawendé F. Bissyandé2, Dongsun Kim2,
David Lo3, Kisub Kim2, Jacques Klein2, Yves Le Traon2
1 National Library of Luxembourg
2 Interdisciplinary Centre for Security, Reliability and Trust (SnT),
University of Luxembourg
3 School of Information Systems, Singapore Management University
1.1 - logotype of the University
of Luxembourg
3.1 - the Interdisciplinary Centre for
Security Reliability and TrustJournal first-track paper; originally published in
the Empirical Software Engineering Journal

2. Programming is always
full of questions.
- My code is correct?
- How did other programmers
implement?
- Anything missing?
- …
2

3. Programming is always
full of questions.
- My code is correct?
- How did other programmers
implement?
- Anything missing?
- …
2

4. Programming is always
full of questions.
- My code is correct?
- How did other programmers
implement?
- Anything missing?
- …
2

5. When you are learning
a new language or library,
- How to use this API?
- Recommended implementations
- Examples
- …
3

6. First aid: Searching for code examples
4

7. First aid: Searching for code examples
4

8. First aid: Searching for code examples
4

9. First aid: Searching for code examples
4

10. "How do I invoke a Java
method when given the
method name as a
string?"
Let’s search for:
5

11. "How do I invoke a Java
method when given the
method name as a
string?"
Let’s search for:
6

12. "How do I invoke a Java
method when given the
method name as a
string?"
6

13. "How do I invoke a Java
method when given the
method name as a
string?"
7

14. "How do I invoke a Java
method when given the
method name as a
string?"
7

15. "How do I invoke a Java
method when given the
method name as a
string?"
8

16. "How do I invoke a Java
method when given the
method name as a
string?"
9

17. "How do I invoke a Java
method when given the
method name as a
string?"
Java
Clear All Filters
Documents:
MessageListenerAdapter.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Jul 09, 2014
292 * @see #buildListenerArguments
293 */
294
protected Object invokeListenerMethod(String methodName, Object[]
JMSException {
295 try {
296 MethodInvoker methodInvoker = new MethodInvoker();
MultiActionController.java
Document type: Java Project: Spring Framework Author: Phillip Webb Date: Nov 22, 2013 0
214 * <p>Allows parameterization of handler method mappings.
215 */
216 public final void setMethodNameResolver(MethodNameResolver method
217 this.methodNameResolver = methodNameResolver;
218 }
NotifyBuilder.java
Document type: Java Project: Apache­Camel Author: Claus Ibsen Date: Apr 10, 2013 06:17
676 return doWhenAnyMatches(predicate, false);
677 }
679
private NotifyBuilder doWhenAnyMatches(final Predicate predicate,
received) {
680 stack.add(new EventPredicateSupport() {
681 private final AtomicBoolean matches = new AtomicBoolean();
SpelReproTests.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Dec 22, 201
413 /** Should be accessing Goo.getKey because 'bar' field evaluates
414 @Test
415 public void indexingAsAPropertyAccess SPR6968 1() {
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zhangduo (48)
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10

18. An experts may know
it is “reflection”.
Java
Clear All Filters
Documents:
MessageListenerAdapter.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Jul 09, 2014
292 * @see #buildListenerArguments
293 */
294
protected Object invokeListenerMethod(String methodName, Object[]
JMSException {
295 try {
296 MethodInvoker methodInvoker = new MethodInvoker();
MultiActionController.java
Document type: Java Project: Spring Framework Author: Phillip Webb Date: Nov 22, 2013 0
214 * <p>Allows parameterization of handler method mappings.
215 */
216 public final void setMethodNameResolver(MethodNameResolver method
217 this.methodNameResolver = methodNameResolver;
218 }
NotifyBuilder.java
Document type: Java Project: Apache­Camel Author: Claus Ibsen Date: Apr 10, 2013 06:17
676 return doWhenAnyMatches(predicate, false);
677 }
679
private NotifyBuilder doWhenAnyMatches(final Predicate predicate,
received) {
680 stack.add(new EventPredicateSupport() {
681 private final AtomicBoolean matches = new AtomicBoolean();
SpelReproTests.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Dec 22, 201
413 /** Should be accessing Goo.getKey because 'bar' field evaluates
414 @Test
415 public void indexingAsAPropertyAccess SPR6968 1() {
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"How do I invoke a Java
method when given the
method name as a
string?"
11

19. An experts may know
it is “reflection”.
Java
Clear All Filters
Documents:
MessageListenerAdapter.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Jul 09, 2014
292 * @see #buildListenerArguments
293 */
294
protected Object invokeListenerMethod(String methodName, Object[]
JMSException {
295 try {
296 MethodInvoker methodInvoker = new MethodInvoker();
MultiActionController.java
Document type: Java Project: Spring Framework Author: Phillip Webb Date: Nov 22, 2013 0
214 * <p>Allows parameterization of handler method mappings.
215 */
216 public final void setMethodNameResolver(MethodNameResolver method
217 this.methodNameResolver = methodNameResolver;
218 }
NotifyBuilder.java
Document type: Java Project: Apache­Camel Author: Claus Ibsen Date: Apr 10, 2013 06:17
676 return doWhenAnyMatches(predicate, false);
677 }
679
private NotifyBuilder doWhenAnyMatches(final Predicate predicate,
received) {
680 stack.add(new EventPredicateSupport() {
681 private final AtomicBoolean matches = new AtomicBoolean();
SpelReproTests.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Dec 22, 201
413 /** Should be accessing Goo.getKey because 'bar' field evaluates
414 @Test
415 public void indexingAsAPropertyAccess SPR6968 1() {
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java reflection
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About 5010 search results for [java reflection]
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45 throw new UnsupportedOperationException();
ReflectionJoinpoint.java
Document type: Java Project: WildFly Author: Ales Justin Date: Jul 25, 2011 09:52 PM
30 * @author <a href="mailto:ales.justin@jboss.org">Ales Justin</a>
31 */
32 public class ReflectionJoinpoint extends TargetJoinpoint {
33 private final BeanInfo beanInfo;
34 private final String methodName;
ReflectionProvider.java
Document type: Java Project: Terasology Author: Immortius Date: Jan 23, 2014 08:35 AM
41 * @author Immortius
42 */
43 public class ReflectionProvider<T> implements PropertyProvider<T> {
44
private static final Logger logger =
LoggerFactory.getLogger(ReflectionProvider.class);
46 private List<Property<T>> properties = Lists.newArrayList();
ReflectionReflectFactory.java
Document type: Java Project: Terasology Author: Immortius Date: Jan 23, 2014 08:35 AM
30 * @author Immortius
31 */
32 public class ReflectionReflectFactory implements ReflectFactory {
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"How do I invoke a Java
method when given the
method name as a
string?"
12

20. Java
Clear All Filters
Documents:
MessageListenerAdapter.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Jul 09, 2014
292 * @see #buildListenerArguments
293 */
294
protected Object invokeListenerMethod(String methodName, Object[]
JMSException {
295 try {
296 MethodInvoker methodInvoker = new MethodInvoker();
MultiActionController.java
Document type: Java Project: Spring Framework Author: Phillip Webb Date: Nov 22, 2013 0
214 * <p>Allows parameterization of handler method mappings.
215 */
216 public final void setMethodNameResolver(MethodNameResolver method
217 this.methodNameResolver = methodNameResolver;
218 }
NotifyBuilder.java
Document type: Java Project: Apache­Camel Author: Claus Ibsen Date: Apr 10, 2013 06:17
676 return doWhenAnyMatches(predicate, false);
677 }
679
private NotifyBuilder doWhenAnyMatches(final Predicate predicate,
received) {
680 stack.add(new EventPredicateSupport() {
681 private final AtomicBoolean matches = new AtomicBoolean();
SpelReproTests.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Dec 22, 201
413 /** Should be accessing Goo.getKey because 'bar' field evaluates
414 @Test
415 public void indexingAsAPropertyAccess SPR6968 1() {
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java reflection
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About 5010 search results for [java reflection]
Clear All Filters
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45 throw new UnsupportedOperationException();
ReflectionJoinpoint.java
Document type: Java Project: WildFly Author: Ales Justin Date: Jul 25, 2011 09:52 PM
30 * @author <a href="mailto:ales.justin@jboss.org">Ales Justin</a>
31 */
32 public class ReflectionJoinpoint extends TargetJoinpoint {
33 private final BeanInfo beanInfo;
34 private final String methodName;
ReflectionProvider.java
Document type: Java Project: Terasology Author: Immortius Date: Jan 23, 2014 08:35 AM
41 * @author Immortius
42 */
43 public class ReflectionProvider<T> implements PropertyProvider<T> {
44
private static final Logger logger =
LoggerFactory.getLogger(ReflectionProvider.class);
46 private List<Property<T>> properties = Lists.newArrayList();
ReflectionReflectFactory.java
Document type: Java Project: Terasology Author: Immortius Date: Jan 23, 2014 08:35 AM
30 * @author Immortius
31 */
32 public class ReflectionReflectFactory implements ReflectFactory {
Content
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Java (5010)
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JavaScript (108)
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APIs actually you need:
Class.forname(),
getDeclaredMethods(),
getReturnType(),
java.lang.reflect.Method
An experts may know
it is “reflection”.
"How do I invoke a Java
method when given the
method name as a
string?"
13

21. Java
Clear All Filters
Documents:
MessageListenerAdapter.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Jul 09, 2014
292 * @see #buildListenerArguments
293 */
294
protected Object invokeListenerMethod(String methodName, Object[]
JMSException {
295 try {
296 MethodInvoker methodInvoker = new MethodInvoker();
MultiActionController.java
Document type: Java Project: Spring Framework Author: Phillip Webb Date: Nov 22, 2013 0
214 * <p>Allows parameterization of handler method mappings.
215 */
216 public final void setMethodNameResolver(MethodNameResolver method
217 this.methodNameResolver = methodNameResolver;
218 }
NotifyBuilder.java
Document type: Java Project: Apache­Camel Author: Claus Ibsen Date: Apr 10, 2013 06:17
676 return doWhenAnyMatches(predicate, false);
677 }
679
private NotifyBuilder doWhenAnyMatches(final Predicate predicate,
received) {
680 stack.add(new EventPredicateSupport() {
681 private final AtomicBoolean matches = new AtomicBoolean();
SpelReproTests.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Dec 22, 201
413 /** Should be accessing Goo.getKey because 'bar' field evaluates
414 @Test
415 public void indexingAsAPropertyAccess SPR6968 1() {
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John Pullokkaran (131)
Aleksey Pivovarov (71)
zhangduo (48)
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Michael McCandless (33)
Report
java reflection
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Java
About 5010 search results for [java reflection]
Clear All Filters
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45 throw new UnsupportedOperationException();
ReflectionJoinpoint.java
Document type: Java Project: WildFly Author: Ales Justin Date: Jul 25, 2011 09:52 PM
30 * @author <a href="mailto:ales.justin@jboss.org">Ales Justin</a>
31 */
32 public class ReflectionJoinpoint extends TargetJoinpoint {
33 private final BeanInfo beanInfo;
34 private final String methodName;
ReflectionProvider.java
Document type: Java Project: Terasology Author: Immortius Date: Jan 23, 2014 08:35 AM
41 * @author Immortius
42 */
43 public class ReflectionProvider<T> implements PropertyProvider<T> {
44
private static final Logger logger =
LoggerFactory.getLogger(ReflectionProvider.class);
46 private List<Property<T>> properties = Lists.newArrayList();
ReflectionReflectFactory.java
Document type: Java Project: Terasology Author: Immortius Date: Jan 23, 2014 08:35 AM
30 * @author Immortius
31 */
32 public class ReflectionReflectFactory implements ReflectFactory {
Content
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APIs actually you need:
Class.forname(),
getDeclaredMethods(),
getReturnType(),
java.lang.reflect.Method
| Reference | SupporReports
forname getDeclaredMethods getReturnType Method
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About 114 search results for [forname getDeclaredMethods getReturnType Method]
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1366 */
1367 public static Method[] getDeclaredMethods(Class clazz) {
1368 Method[] methods = clazz.getMethods();
1369 ArrayList list=new ArrayList();
BeanUtils.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Dec 22, 2014 05:46 PM Clones
250
public static Method findDeclaredMethodWithMinimalParameters(Class<?> clazz, String
methodName)
251 throws IllegalArgumentException {
253
Method targetMethod = findMethodWithMinimalParameters(clazz.getDeclaredMethods(),
methodName);
254 if (targetMethod == null && clazz.getSuperclass() != null) {
255
targetMethod = findDeclaredMethodWithMinimalParameters(clazz.getSuperclass(),
methodName);
HamletGen.java
Document type: Java Project: Apache­Hadoop Common Author: Vinod Kumar Vavilapalli Date: Jun 17, 2013 03:32 AM
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An experts may know
it is “reflection”.
"How do I invoke a Java
method when given the
method name as a
string?"
14

22. "How do I invoke a Java
method when given the
method name as a
string?"
An experts may know
it is “reflection”.
Java
Clear All Filters
Documents:
MessageListenerAdapter.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Jul 09, 2014
292 * @see #buildListenerArguments
293 */
294
protected Object invokeListenerMethod(String methodName, Object[]
JMSException {
295 try {
296 MethodInvoker methodInvoker = new MethodInvoker();
MultiActionController.java
Document type: Java Project: Spring Framework Author: Phillip Webb Date: Nov 22, 2013 0
214 * <p>Allows parameterization of handler method mappings.
215 */
216 public final void setMethodNameResolver(MethodNameResolver method
217 this.methodNameResolver = methodNameResolver;
218 }
NotifyBuilder.java
Document type: Java Project: Apache­Camel Author: Claus Ibsen Date: Apr 10, 2013 06:17
676 return doWhenAnyMatches(predicate, false);
677 }
679
private NotifyBuilder doWhenAnyMatches(final Predicate predicate,
received) {
680 stack.add(new EventPredicateSupport() {
681 private final AtomicBoolean matches = new AtomicBoolean();
SpelReproTests.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Dec 22, 201
413 /** Should be accessing Goo.getKey because 'bar' field evaluates
414 @Test
415 public void indexingAsAPropertyAccess SPR6968 1() {
Check­in Comments
Projects (22)
Apache­Hive (157)
Apache­Hbase (92)
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Java (455)
Plain (966)
JavaScript (159)
Html (40)
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Authors (35)
John Pullokkaran (131)
Aleksey Pivovarov (71)
zhangduo (48)
andy_jefferson (36)
Michael McCandless (33)
Report
java reflection
Advanced Search
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Java
About 5010 search results for [java reflection]
Clear All Filters
Documents:
45 throw new UnsupportedOperationException();
ReflectionJoinpoint.java
Document type: Java Project: WildFly Author: Ales Justin Date: Jul 25, 2011 09:52 PM
30 * @author <a href="mailto:ales.justin@jboss.org">Ales Justin</a>
31 */
32 public class ReflectionJoinpoint extends TargetJoinpoint {
33 private final BeanInfo beanInfo;
34 private final String methodName;
ReflectionProvider.java
Document type: Java Project: Terasology Author: Immortius Date: Jan 23, 2014 08:35 AM
41 * @author Immortius
42 */
43 public class ReflectionProvider<T> implements PropertyProvider<T> {
44
private static final Logger logger =
LoggerFactory.getLogger(ReflectionProvider.class);
46 private List<Property<T>> properties = Lists.newArrayList();
ReflectionReflectFactory.java
Document type: Java Project: Terasology Author: Immortius Date: Jan 23, 2014 08:35 AM
30 * @author Immortius
31 */
32 public class ReflectionReflectFactory implements ReflectFactory {
Content
Source Code and Documents
Check­in Comments
Projects (56)
DataNucleus (670)
SVN_SCMI_CLI_ performance (670)
IntelliJ IDEA Community Edition (610)
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Show more
Document Types (19)
Java (5010)
Plain (1025)
XML (472)
Html (118)
JavaScript (108)
Show more
APIs actually you need:
Class.forname(),
getDeclaredMethods(),
getReturnType(),
java.lang.reflect.Method
| Reference | SupporReports
forname getDeclaredMethods getReturnType Method
Advanced Search
Browse Projects
Download Results
Java
About 114 search results for [forname getDeclaredMethods getReturnType Method]
Clear All Filters
Documents:
1366 */
1367 public static Method[] getDeclaredMethods(Class clazz) {
1368 Method[] methods = clazz.getMethods();
1369 ArrayList list=new ArrayList();
BeanUtils.java
Document type: Java Project: Spring Framework Author: Juergen Hoeller Date: Dec 22, 2014 05:46 PM Clones
250
public static Method findDeclaredMethodWithMinimalParameters(Class<?> clazz, String
methodName)
251 throws IllegalArgumentException {
253
Method targetMethod = findMethodWithMinimalParameters(clazz.getDeclaredMethods(),
methodName);
254 if (targetMethod == null && clazz.getSuperclass() != null) {
255
targetMethod = findDeclaredMethodWithMinimalParameters(clazz.getSuperclass(),
methodName);
HamletGen.java
Document type: Java Project: Apache­Hadoop Common Author: Vinod Kumar Vavilapalli Date: Jun 17, 2013 03:32 AM
Content
Source Code and Documents
Check­in Comments
Projects (7)
DataNucleus (54)
SVN_SCMI_CLI_ performance (54)
Spring Framework (2)
Apache­Camel (1)
Apache­Hadoop Common (1)
Show more
Document Types (2)
Java (114)
Vocabulary Mismatch Problem
15

23. Yes, we can ask:
16

24. “This is a snippet
for you.”
How should they look like?
What if you need
real code examples?
17

25. Intuition
18

26. Insight from SMT
[From English to Korean]
When a translator
does not work well…
19

27. Insight from SMT
[From English to Korean]
When a translator
does not work well…
19

28. Insight from SMT
[From English to Korean]
When a translator
does not work well…
19

29. Insight from SMT
[From English to Korean]
When a translator
does not work well…
19

30. Insight from SMT
When a translator
does not work well…
[From English to Korean]
20

31. Insight from SMT
When a translator
does not work well…
20

32. Insight from SMT
Taking two steps!
21

33. Insight from SMT
Taking two steps!
English —> Japanese
21

34. Insight from SMT
Taking two steps!
English —> Japanese —> Korean
21

35. Augmenting queries
Query
22

36. Augmenting queries
Query
invoke
Java
method
name
string
22

37. Augmenting queries
Query
invoke
Java
method
name
string
22

38. Augmenting queries
Query
invoke
Java
method
name
string
Mappings between
questions and snippets
22

39. Augmenting queries
Query
invoke
Java
method
name
string
Mappings between
questions and snippets
22

40. Augmenting queries
Query
Augmented query
invoke
Java
method
name
string
Mappings between
questions and snippets
22

41. Augmenting queries
Query
Augmented query
invoke
Java
method
name
string
Mappings between
questions and snippets
22

42. Augmenting queries
Query
Augmented query
java.lang.reflect.Method
Class.forName()
getDeclaredMethods()
getReturnType()
invoke
Java
method
name
string
Mappings between
questions and snippets
22

43. Augmenting queries
Query
invoke, Java, method,
name, string
Augmented query
java.lang.reflect.Method
Class.forName()
getDeclaredMethods()
getReturnType()
invoke
Java
method
name
string
Mappings between
questions and snippets
22

44. ApproachCoCaBu:Code voCaBulary
23

45. Search
Query
Search
Proxy
Relevant
Posts
Code Query
Generator
Snippet
Index
Augmented
Query
Code
Index
Code Search
Engine
(a) (b) (c)
Search
Results
Overview
24

46. Generating random
words in Java?
<<Query>>
(1) Searching for Similar Questions (+ Snippets)
25

47. Generating random
words in Java?
<<Query>>
How to create random string with random characters? Random string generation
Random word from array list
How to Generate Words Randomly in JavaGenerating random words
of a certain length in java?
(1) Searching for Similar Questions (+ Snippets)
25

48. Generating random
words in Java?
<<Query>>
String Functions
Generics
Collections & Util Package
Nested Classes
Networking
File I/O Operations
Java Annotations
JDBC Examples
Spring Core
Java Interview Questions
Java Interview Programs
Java Restful Web Services
JSON in Java
JUnit
Java Design Patterns
Search Algorithms
Sorting Algorithms
Data Structures
Gradle Configurations
JBoss Configurations
Java Issues
Output:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
package com.java2novice.random;
import java.util.Random;
public class MyStringRandomGen {
private static final String CHAR_LIST =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
private static final int RANDOM_STRING_LENGTH = 10;
/**
* This method generates random string
* @return
*/
public String generateRandomString(){
StringBuffer randStr = new StringBuffer();
for(int i=0; i<RANDOM_STRING_LENGTH; i++){
int number = getRandomNumber();
char ch = CHAR_LIST.charAt(number);
randStr.append(ch);
}
return randStr.toString();
}
/**
* This method generates random numbers
* @return int
*/
private int getRandomNumber() {
int randomInt = 0;
Random randomGenerator = new Random();
randomInt = randomGenerator.nextInt(CHAR_LIST.length());
if (randomInt ‐ 1 == ‐1) {
return randomInt;
} else {
return randomInt ‐ 1;
}
}
public static void main(String a[]){
MyStringRandomGen msr = new MyStringRandomGen();
System.out.println(msr.generateRandomString());
System.out.println(msr.generateRandomString());
System.out.println(msr.generateRandomString());
System.out.println(msr.generateRandomString());
System.out.println(msr.generateRandomString());
System.out.println(msr.generateRandomString());
System.out.println(msr.generateRandomString());
}
}
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How to create random string with random characters? Random string generation
posted 10/13/2004 1:55 AM
posted 10/13/2004 2:15 AM
posted 10/13/2004 2:17 AM
posted 10/13/2004 5:45 AM
Anna Hays
Ranch Hand
Joined: Nov 09, 2003
Posts: 131
Hi, can Java generate a string of random charactors? I need a password generation. Can so
me an idea of what's the proper way of doing this please? Thanks.
Michael Dunn
Ranch Hand
Joined: Jun 09, 2003
Posts: 4632
This might be one way
Steve Deadsea
Ranch Hand
Joined: Dec 03, 2001
Posts: 125
I wrote libraries for doing this:
http://ostermiller.org/utils/RandPass.html
somkiat
puisungnoen
Ranch Hand
Joined: Jul 04, 2003
Posts: 1312
Originally posted by Anna Kafei:
Hi, can Java generate a string of random charactors? I need a password generation. Can som
me an idea of what's the proper way of doing this please? Thanks.
1. Specified your data for random.
2. Specified length for generate password.
3. Create random utilities , you can use Math.random() method or java.util.Random class.
1
2
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8
9
10
11
12
13
14
class Testing
{
public Testing()
{
final int PASSWORD_LENGTH = 8;
StringBuffer sb = new StringBuffer();
for (int x = 0; x < PASSWORD_LENGTH; x++)
{
sb.append((char)((int)(Math.random()*26)+97));
}
System.out.println(sb.toString());
}
public static void main(String[] args){new Testing();}
}
//Construct String from file
public static void constructor(String filename) throws IOException{
ArrayList words = new ArrayList();
BufferedReader read = new BufferedReader(new FileReader("filename"));
String line = read.readLine();
while (line != null){
words.add(line);
//line = reader.readline();
}
}
public static void getRandomWord(){
Random rand = new Random();
String randomWord = words.get(rand.nextInt(words.size));
}
}
java random arraylist
asked Dec 3 '13 at 18:35
user3062703
1 1 1
– So you're trying to get a random word from a file and output it? Tatakai Wasumi Dec 3 '13 at 18:49
–
Member variables (e.g. 'words') cannot be referenced from static methods (e.g. 'getRandomWord()').
declare 'words' as static or remove 'static' keyword from method signature. Hollis Waite Dec 3 '13
18:49
– you should use something like : int rand= minimum + (int)(Math.random()*maximum); Clad Clad De
at 18:50
– Try this link maybe it will help you here Tatakai Wasumi Dec 3 '13 at 18:52
–
@TatakaiWasumi Indeed. From what I understand the first part of my code takes words from a file an
them in an arraylist. The second part of my code needs to generate a random number and from that,
the corresponding word in the arraylist. I'm having issues with the fact that words is private... Says I
reach it from getRandomWord user3062703 Dec 3 '13 at 18:57
1 Answer
This will help you I think It's able to get a random word from an array of strings
private static String[] names = { "Terminator", "Slicer","Ninja", "cow", "Robot",
"littlegirl" };
name = names[(int) (Math.random() * names.length)];
System.out.println(names);
Random word from array list
How to Generate Words Randomly in Java
How to Add Buttons and
Text to Your JavaFX
Project
Making You
Easier with
How to Generate Words Rando
By Barry Burd from Beginning Programming with Java Fo
Most Java programs don’t work correctly the first time you run
error on your part. This code is a case in point.
To write this code, you need a way to generate three­letter wo
anAccount.lastName = "" +
(char) (myRandom.nextInt(26) + 'A') +
(char) (myRandom.nextInt(26) + 'a') +
(char) (myRandom.nextInt(26) + 'a');
Here’s how the code works:
Each call to the Random.nextInt(26)generates a num
Adding'A'gives you a number from 65 to 90.
To store a letter 'A', the computer puts the number 65 in
adding 'A' to 25 gives you 90.
Applying(char)to a number turns the number into a cha
To store the letters 'A' through 'Z', the computer puts th
speaks 9
Promoted by Babbel
Promoted by Lifestyle Journal
Generating random words
of a certain length in java?
Do you need actual English words, or just random strings that only contain letters a­z?
If you need actual English words, the only way to do it is to use a dictionary, and select words from it
at random.
If you don't need English words, then something like this will do:
share edit flag edited Feb 10 '11 at 1:01
David Yaw
22k 2 45 81
answered Feb 10 '11 at 0:17
public static String[] generateRandomWords(int numberOfWords)
{
String[] randomStrings = new String[numberOfWords];
Random random = new Random();
for(int i = 0; i < numberOfWords; i++)
{
char[] word = new char[random.nextInt(8)+3]; // words of length 3 through 10.
for(int j = 0; j < word.length; j++)
{
word[j] = (char)('a' + random.nextInt(26));
}
randomStrings[i] = new String(word);
}
return randomStrings;
}
(1) Searching for Similar Questions (+ Snippets)
25

49. (2) Generating Augmented Queries
26

50. Generating random
words in Java?
<<Query>>
(2) Generating Augmented Queries
26

51. Generating random
words in Java?
<<Query>>
(2) Generating Augmented Queries
26

52. Generating random words of a certain length in java?
Do you need actual English words, or just random strings that only contain letters a­z?
If you need actual English words, the only way to do it is to use a dictionary, and select words from it
at random.
If you don't need English words, then something like this will do:
public static String[] generateRandomWords(int numberOfWords)
{
String[] randomStrings = new String[numberOfWords];
Random random = new Random();
for(int i = 0; i < numberOfWords; i++)
{
char[] word = new char[random.nextInt(8)+3]; // words of length 3 through 10.
for(int j = 0; j < word.length; j++)
{
word[j] = (char)('a' + random.nextInt(26));
}
randomStrings[i] = new String(word);
}
return randomStrings;
}
Generating random
words in Java?
<<Query>>
(2) Generating Augmented Queries
26

53. Generating random words of a certain length in java?
Do you need actual English words, or just random strings that only contain letters a­z?
If you need actual English words, the only way to do it is to use a dictionary, and select words from it
at random.
If you don't need English words, then something like this will do:
public static String[] generateRandomWords(int numberOfWords)
{
String[] randomStrings = new String[numberOfWords];
Random random = new Random();
for(int i = 0; i < numberOfWords; i++)
{
char[] word = new char[random.nextInt(8)+3]; // words of length 3 through 10.
for(int j = 0; j < word.length; j++)
{
word[j] = (char)('a' + random.nextInt(26));
}
randomStrings[i] = new String(word);
}
return randomStrings;
}
Generating random
words in Java?
<<Query>>
(2) Generating Augmented Queries
26

54. 3.3 Code Query Generator
The Code Query Generator creates a code search query
that augments the free-form query taken by the search proxy
(Section 3.2). This augmented query is a list of program ele-
ments, such as class and method names (e.g., Math.random),
as well as natural language terms which can be used to match
documentation.
To generate the augmented query, CoCaBu must extract
structural code entities from code snippets embedded in the
answers to the questions in the relevant posts returned by
the search proxy (Figure 6(b)). The code query generator
component only considers accepted answers, i.e., answers
approved by the Q&A site community.
The augmented query produced by the code query gener-
3.3 Code Query Generator
The Code Query Generator creates a code search query
that augments the free-form query taken by the search proxy
(Section 3.2). This augmented query is a list of program ele-
ments, such as class and method names (e.g., Math.random),
as well as natural language terms which can be used to match
documentation.
To generate the augmented query, CoCaBu must extract
structural code entities from code snippets embedded in the
answers to the questions in the relevant posts returned by
the search proxy (Figure 6(b)). The code query generator
component only considers accepted answers, i.e., answers
approved by the Q&A site community.
The augmented query produced by the code query gener-
ator is illustrated in Figure 6 in the Lucene search engine
query format.
Generating random
words in Java?
How to create random string with random c
JAVA EXAMPLE PROGRAMS
Home
Fundamentals
Constructors
Exception Handling
Threads
String Functions
Generics
Collections & Util Package
Nested Classes
Networking
File I/O Operations
Java Annotations
JDBC Examples
Spring Core
Java Interview Questions
Program: How to create random string with rand
Description:
Write a program to generate random string of length 10 charactors. E
program should generate random string.
Code:
Monitor Jav
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package com.java2novice.random;
import java.util.Random;
public class MyStringRandomGen {
private static final String CHAR_LIST =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQ
private static final int RANDOM_STRING_LENGTH =
/**
* This method generates random string
* @return
*/
public String generateRandomString(){
StringBuffer randStr = new StringBuffer();
for(int i=0; i<RANDOM_STRING_LENGTH; i++){
int number = getRandomNumber();
char ch = CHAR_LIST.charAt(number);
randStr.append(ch);
}
return randStr.toString();
}
Random string generation
posted 10/13/2004 1:55 AM
posted 10/13/2004 2:15 AM
A friendly
place for
programming
greenhorns!
Bi
Search | Java FAQ | Recen
Win a copy of Introducing
JavaRanch » Java Forums » Java » Java in General
Author Random string generatio
Anna Hays
Ranch Hand
Joined: Nov 09, 2003
Posts: 131
Hi, can Java generate a string of random charactors? I n
me an idea of what's the proper way of doing this please
Michael Dunn
Ranch Hand
Joined: Jun 09, 2003
Posts: 4632
This might be one way
1
2
3
4
5
6
7
class Testing
{
public Testing()
{
final int PASSWORD_LENGTH = 8;
StringBuffer sb = new StringBuffer();
for (int x = 0; x < PASSWORD_LENGTH; How to Genera
How to Add Butt
Text to Your Jav
Project
How to Gen
By Barry Burd from B
Most Java programs do
error on your part. This
To write this code, you
10 easy tricks to learn any
language from a man who
speaks 9
Promoted by Babbel
private ArrayList
//Construct Strin
public static voi
ArrayList words =
BufferedReader re
String line = rea
while (line !=
words.add(lin
//line = read
}
}
public static voi
Random rand = new R
String randomWord =
}
}
java random arra
asked Dec 3 '13 at 18
user3062703
1 1 1
So you're trying to g
Member variables (e
declare 'words' as s
18:49
you should use som
at 18:50
Try this link maybe
@TatakaiWasumi In
them in an arraylist.
the corresponding w
reach it from getRa
2
<<Query>>
<<Relevent-Posts>>
2 Answers(a)
example query whose field semantics was pre
in Table 1:
• terms, excluding stop words, in the use
(cf. Figure 6(a)) are kept, after stemm
mented query (cf. Figure 6(c), lines
• structural code entities collected from
(cf. Figure 6(b)) are mentioned with
non-qualified/partially qualified metho
class) in the augmented query (cf. Figu
IxJ)
To accelerate code query generation, Co
an index of posts. Typically, Q&A forums
of their posts. These posts are often forma
tural language such as XML. For example,
flow posts, code snippets are enclosed in <co
As shown in Figure 8, our approach takes
posts from a Q&A site and extracts metadat
tion title) and code snippets for each post.
pet is then analyzed to retrieve the structur
This phase presents challenges that will be a
tion 3.1.
Metadata
pq_method_invocation:Random.nextInt
pq_method_invocation:Math.random
class:word class:char
class:int class:String
class:Random
instance:String
instance:Random
nq_method_invocation:nextInt
code:gener
code:random
code:word
...
Figure 7: Augmented query corresponding to the sn
in Figure ??.
Generating random words of a certain length in java?
Do you need actual English words, or just random strings that only contain letters a­z?
If you need actual English words, the only way to do it is to use a dictionary, and select words from it
at random.
If you don't need English words, then something like this will do:
public static String[] generateRandomWords(int numberOfWords)
{
String[] randomStrings = new String[numberOfWords];
Random random = new Random();
for(int i = 0; i < numberOfWords; i++)
{
char[] word = new char[random.nextInt(8)+3]; // words of length 3 through 10.
for(int j = 0; j < word.length; j++)
{
word[j] = (char)('a' + random.nextInt(26));
}
randomStrings[i] = new String(word);
}
return randomStrings;
}
Generating random
words in Java?
<<Query>>
(2) Generating Augmented Queries
26

55. 3.3 Code Query Generator
The Code Query Generator creates a code search query
that augments the free-form query taken by the search proxy
(Section 3.2). This augmented query is a list of program ele-
ments, such as class and method names (e.g., Math.random),
as well as natural language terms which can be used to match
documentation.
To generate the augmented query, CoCaBu must extract
structural code entities from code snippets embedded in the
answers to the questions in the relevant posts returned by
the search proxy (Figure 6(b)). The code query generator
component only considers accepted answers, i.e., answers
approved by the Q&A site community.
The augmented query produced by the code query gener-
3.3 Code Query Generator
The Code Query Generator creates a code search query
that augments the free-form query taken by the search proxy
(Section 3.2). This augmented query is a list of program ele-
ments, such as class and method names (e.g., Math.random),
as well as natural language terms which can be used to match
documentation.
To generate the augmented query, CoCaBu must extract
structural code entities from code snippets embedded in the
answers to the questions in the relevant posts returned by
the search proxy (Figure 6(b)). The code query generator
component only considers accepted answers, i.e., answers
approved by the Q&A site community.
The augmented query produced by the code query gener-
ator is illustrated in Figure 6 in the Lucene search engine
query format.
Generating random
words in Java?
How to create random string with random c
JAVA EXAMPLE PROGRAMS
Home
Fundamentals
Constructors
Exception Handling
Threads
String Functions
Generics
Collections & Util Package
Nested Classes
Networking
File I/O Operations
Java Annotations
JDBC Examples
Spring Core
Java Interview Questions
Program: How to create random string with rand
Description:
Write a program to generate random string of length 10 charactors. E
program should generate random string.
Code:
Monitor Jav
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
package com.java2novice.random;
import java.util.Random;
public class MyStringRandomGen {
private static final String CHAR_LIST =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQ
private static final int RANDOM_STRING_LENGTH =
/**
* This method generates random string
* @return
*/
public String generateRandomString(){
StringBuffer randStr = new StringBuffer();
for(int i=0; i<RANDOM_STRING_LENGTH; i++){
int number = getRandomNumber();
char ch = CHAR_LIST.charAt(number);
randStr.append(ch);
}
return randStr.toString();
}
Random string generation
posted 10/13/2004 1:55 AM
posted 10/13/2004 2:15 AM
A friendly
place for
programming
greenhorns!
Bi
Search | Java FAQ | Recen
Win a copy of Introducing
JavaRanch » Java Forums » Java » Java in General
Author Random string generatio
Anna Hays
Ranch Hand
Joined: Nov 09, 2003
Posts: 131
Hi, can Java generate a string of random charactors? I n
me an idea of what's the proper way of doing this please
Michael Dunn
Ranch Hand
Joined: Jun 09, 2003
Posts: 4632
This might be one way
1
2
3
4
5
6
7
class Testing
{
public Testing()
{
final int PASSWORD_LENGTH = 8;
StringBuffer sb = new StringBuffer();
for (int x = 0; x < PASSWORD_LENGTH; How to Genera
How to Add Butt
Text to Your Jav
Project
How to Gen
By Barry Burd from B
Most Java programs do
error on your part. This
To write this code, you
10 easy tricks to learn any
language from a man who
speaks 9
Promoted by Babbel
private ArrayList
//Construct Strin
public static voi
ArrayList words =
BufferedReader re
String line = rea
while (line !=
words.add(lin
//line = read
}
}
public static voi
Random rand = new R
String randomWord =
}
}
java random arra
asked Dec 3 '13 at 18
user3062703
1 1 1
So you're trying to g
Member variables (e
declare 'words' as s
18:49
you should use som
at 18:50
Try this link maybe
@TatakaiWasumi In
them in an arraylist.
the corresponding w
reach it from getRa
2
<<Query>>
<<Relevent-Posts>>
2 Answers(a)
example query whose field semantics was pre
in Table 1:
• terms, excluding stop words, in the use
(cf. Figure 6(a)) are kept, after stemm
mented query (cf. Figure 6(c), lines
• structural code entities collected from
(cf. Figure 6(b)) are mentioned with
non-qualified/partially qualified metho
class) in the augmented query (cf. Figu
IxJ)
To accelerate code query generation, Co
an index of posts. Typically, Q&A forums
of their posts. These posts are often forma
tural language such as XML. For example,
flow posts, code snippets are enclosed in <co
As shown in Figure 8, our approach takes
posts from a Q&A site and extracts metadat
tion title) and code snippets for each post.
pet is then analyzed to retrieve the structur
This phase presents challenges that will be a
tion 3.1.
Metadata
pq_method_invocation:Random.nextInt
pq_method_invocation:Math.random
class:word class:char
class:int class:String
class:Random
instance:String
instance:Random
nq_method_invocation:nextInt
code:gener
code:random
code:word
...
Figure 7: Augmented query corresponding to the sn
in Figure ??.
Generating random words of a certain length in java?
Do you need actual English words, or just random strings that only contain letters a­z?
If you need actual English words, the only way to do it is to use a dictionary, and select words from it
at random.
If you don't need English words, then something like this will do:
public static String[] generateRandomWords(int numberOfWords)
{
String[] randomStrings = new String[numberOfWords];
Random random = new Random();
for(int i = 0; i < numberOfWords; i++)
{
char[] word = new char[random.nextInt(8)+3]; // words of length 3 through 10.
for(int j = 0; j < word.length; j++)
{
word[j] = (char)('a' + random.nextInt(26));
}
randomStrings[i] = new String(word);
}
return randomStrings;
}
Generating random
words in Java?
<<Query>>
27

56. 3.3 Code Query Generator
The Code Query Generator creates a code search query
that augments the free-form query taken by the search proxy
(Section 3.2). This augmented query is a list of program ele-
ments, such as class and method names (e.g., Math.random),
as well as natural language terms which can be used to match
documentation.
To generate the augmented query, CoCaBu must extract
structural code entities from code snippets embedded in the
answers to the questions in the relevant posts returned by
the search proxy (Figure 6(b)). The code query generator
component only considers accepted answers, i.e., answers
approved by the Q&A site community.
The augmented query produced by the code query gener-
3.3 Code Query Generator
The Code Query Generator creates a code search query
that augments the free-form query taken by the search proxy
(Section 3.2). This augmented query is a list of program ele-
ments, such as class and method names (e.g., Math.random),
as well as natural language terms which can be used to match
documentation.
To generate the augmented query, CoCaBu must extract
structural code entities from code snippets embedded in the
answers to the questions in the relevant posts returned by
the search proxy (Figure 6(b)). The code query generator
component only considers accepted answers, i.e., answers
approved by the Q&A site community.
The augmented query produced by the code query gener-
ator is illustrated in Figure 6 in the Lucene search engine
query format.
Generating random
words in Java?
How to create random string with random c
JAVA EXAMPLE PROGRAMS
Home
Fundamentals
Constructors
Exception Handling
Threads
String Functions
Generics
Collections & Util Package
Nested Classes
Networking
File I/O Operations
Java Annotations
JDBC Examples
Spring Core
Java Interview Questions
Program: How to create random string with rand
Description:
Write a program to generate random string of length 10 charactors. E
program should generate random string.
Code:
Monitor Jav
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
package com.java2novice.random;
import java.util.Random;
public class MyStringRandomGen {
private static final String CHAR_LIST =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQ
private static final int RANDOM_STRING_LENGTH =
/**
* This method generates random string
* @return
*/
public String generateRandomString(){
StringBuffer randStr = new StringBuffer();
for(int i=0; i<RANDOM_STRING_LENGTH; i++){
int number = getRandomNumber();
char ch = CHAR_LIST.charAt(number);
randStr.append(ch);
}
return randStr.toString();
}
Random string generation
posted 10/13/2004 1:55 AM
posted 10/13/2004 2:15 AM
A friendly
place for
programming
greenhorns!
Bi
Search | Java FAQ | Recen
Win a copy of Introducing
JavaRanch » Java Forums » Java » Java in General
Author Random string generatio
Anna Hays
Ranch Hand
Joined: Nov 09, 2003
Posts: 131
Hi, can Java generate a string of random charactors? I n
me an idea of what's the proper way of doing this please
Michael Dunn
Ranch Hand
Joined: Jun 09, 2003
Posts: 4632
This might be one way
1
2
3
4
5
6
7
class Testing
{
public Testing()
{
final int PASSWORD_LENGTH = 8;
StringBuffer sb = new StringBuffer();
for (int x = 0; x < PASSWORD_LENGTH; How to Genera
How to Add Butt
Text to Your Jav
Project
How to Gen
By Barry Burd from B
Most Java programs do
error on your part. This
To write this code, you
10 easy tricks to learn any
language from a man who
speaks 9
Promoted by Babbel
private ArrayList
//Construct Strin
public static voi
ArrayList words =
BufferedReader re
String line = rea
while (line !=
words.add(lin
//line = read
}
}
public static voi
Random rand = new R
String randomWord =
}
}
java random arra
asked Dec 3 '13 at 18
user3062703
1 1 1
So you're trying to g
Member variables (e
declare 'words' as s
18:49
you should use som
at 18:50
Try this link maybe
@TatakaiWasumi In
them in an arraylist.
the corresponding w
reach it from getRa
2
<<Query>>
<<Relevent-Posts>>
2 Answers(a)
example query whose field semantics was pre
in Table 1:
• terms, excluding stop words, in the use
(cf. Figure 6(a)) are kept, after stemm
mented query (cf. Figure 6(c), lines
• structural code entities collected from
(cf. Figure 6(b)) are mentioned with
non-qualified/partially qualified metho
class) in the augmented query (cf. Figu
IxJ)
To accelerate code query generation, Co
an index of posts. Typically, Q&A forums
of their posts. These posts are often forma
tural language such as XML. For example,
flow posts, code snippets are enclosed in <co
As shown in Figure 8, our approach takes
posts from a Q&A site and extracts metadat
tion title) and code snippets for each post.
pet is then analyzed to retrieve the structur
This phase presents challenges that will be a
tion 3.1.
Metadata
pq_method_invocation:Random.nextInt
pq_method_invocation:Math.random
class:word class:char
class:int class:String
class:Random
instance:String
instance:Random
nq_method_invocation:nextInt
code:gener
code:random
code:word
...
Figure 7: Augmented query corresponding to the sn
in Figure ??.
27

57. 3.3 Code Query Generator
The Code Query Generator creates a code search query
that augments the free-form query taken by the search proxy
(Section 3.2). This augmented query is a list of program ele-
ments, such as class and method names (e.g., Math.random),
as well as natural language terms which can be used to match
documentation.
To generate the augmented query, CoCaBu must extract
structural code entities from code snippets embedded in the
answers to the questions in the relevant posts returned by
the search proxy (Figure 6(b)). The code query generator
component only considers accepted answers, i.e., answers
approved by the Q&A site community.
The augmented query produced by the code query gener-
3.3 Code Query Generator
The Code Query Generator creates a code search query
that augments the free-form query taken by the search proxy
(Section 3.2). This augmented query is a list of program ele-
ments, such as class and method names (e.g., Math.random),
as well as natural language terms which can be used to match
documentation.
To generate the augmented query, CoCaBu must extract
structural code entities from code snippets embedded in the
answers to the questions in the relevant posts returned by
the search proxy (Figure 6(b)). The code query generator
component only considers accepted answers, i.e., answers
approved by the Q&A site community.
The augmented query produced by the code query gener-
ator is illustrated in Figure 6 in the Lucene search engine
query format.
Generating random
words in Java?
How to create random string with random c
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Program: How to create random string with rand
Description:
Write a program to generate random string of length 10 charactors. E
program should generate random string.
Code:
Monitor Jav
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package com.java2novice.random;
import java.util.Random;
public class MyStringRandomGen {
private static final String CHAR_LIST =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQ
private static final int RANDOM_STRING_LENGTH =
/**
* This method generates random string
* @return
*/
public String generateRandomString(){
StringBuffer randStr = new StringBuffer();
for(int i=0; i<RANDOM_STRING_LENGTH; i++){
int number = getRandomNumber();
char ch = CHAR_LIST.charAt(number);
randStr.append(ch);
}
return randStr.toString();
}
Random string generation
posted 10/13/2004 1:55 AM
posted 10/13/2004 2:15 AM
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JavaRanch » Java Forums » Java » Java in General
Author Random string generatio
Anna Hays
Ranch Hand
Joined: Nov 09, 2003
Posts: 131
Hi, can Java generate a string of random charactors? I n
me an idea of what's the proper way of doing this please
Michael Dunn
Ranch Hand
Joined: Jun 09, 2003
Posts: 4632
This might be one way
1
2
3
4
5
6
7
class Testing
{
public Testing()
{
final int PASSWORD_LENGTH = 8;
StringBuffer sb = new StringBuffer();
for (int x = 0; x < PASSWORD_LENGTH; How to Genera
How to Add Butt
Text to Your Jav
Project
How to Gen
By Barry Burd from B
Most Java programs do
error on your part. This
To write this code, you
10 easy tricks to learn any
language from a man who
speaks 9
Promoted by Babbel
private ArrayList
//Construct Strin
public static voi
ArrayList words =
BufferedReader re
String line = rea
while (line !=
words.add(lin
//line = read
}
}
public static voi
Random rand = new R
String randomWord =
}
}
java random arra
asked Dec 3 '13 at 18
user3062703
1 1 1
So you're trying to g
Member variables (e
declare 'words' as s
18:49
you should use som
at 18:50
Try this link maybe
@TatakaiWasumi In
them in an arraylist.
the corresponding w
reach it from getRa
2
<<Query>>
<<Relevent-Posts>>
2 Answers(a)
example query whose field semantics was pre
in Table 1:
• terms, excluding stop words, in the use
(cf. Figure 6(a)) are kept, after stemm
mented query (cf. Figure 6(c), lines
• structural code entities collected from
(cf. Figure 6(b)) are mentioned with
non-qualified/partially qualified metho
class) in the augmented query (cf. Figu
IxJ)
To accelerate code query generation, Co
an index of posts. Typically, Q&A forums
of their posts. These posts are often forma
tural language such as XML. For example,
flow posts, code snippets are enclosed in <co
As shown in Figure 8, our approach takes
posts from a Q&A site and extracts metadat
tion title) and code snippets for each post.
pet is then analyzed to retrieve the structur
This phase presents challenges that will be a
tion 3.1.
Metadata
pq_method_invocation:Random.nextInt
pq_method_invocation:Math.random
class:word class:char
class:int class:String
class:Random
instance:String
instance:Random
nq_method_invocation:nextInt
code:gener
code:random
code:word
...
Figure 7: Augmented query corresponding to the sn
in Figure ??.
28

58. y
y
-
,
h
t
e
y
r
s
-
e
arch proxy
ogram ele-
h.random),
d to match
ust extract
ded in the
turned by
generator
., answers
ery gener-
rch engine
How to create random string with random characters?
dling
ns
Util Package
tions
ns
s
Questions
Programs
eb Services
Program: How to create random string with random characters?
Description:
Write a program to generate random string of length 10 charactors. Every time you call the method, the
program should generate random string.
Code:
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package com.java2novice.random;
import java.util.Random;
public class MyStringRandomGen {
private static final String CHAR_LIST =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
private static final int RANDOM_STRING_LENGTH = 10;
/**
* This method generates random string
* @return
*/
public String generateRandomString(){
StringBuffer randStr = new StringBuffer();
for(int i=0; i<RANDOM_STRING_LENGTH; i++){
int number = getRandomNumber();
char ch = CHAR_LIST.charAt(number);
randStr.append(ch);
}
return randStr.toString();
}
/**
* This method generates random numbers
* @return int
*/
private int getRandomNumber() {
int randomInt = 0;
Random randomGenerator = new Random();
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Random string generation
posted 10/13/2004 1:55 AM
posted 10/13/2004 2:15 AM
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JavaRanch » Java Forums » Java » Java in General
Author Random string generation
Anna Hays
Ranch Hand
Joined: Nov 09, 2003
Posts: 131
Hi, can Java generate a string of random charactors? I need a password generation. Can someone give
me an idea of what's the proper way of doing this please? Thanks.
Michael Dunn
Ranch Hand
Joined: Jun 09, 2003
Posts: 4632
This might be one way
1
2
3
4
5
6
7
8
9
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11
12
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14
class Testing
{
public Testing()
{
final int PASSWORD_LENGTH = 8;
StringBuffer sb = new StringBuffer();
for (int x = 0; x < PASSWORD_LENGTH; x++)
{
sb.append((char)((int)(Math.random()*26)+97));
}
System.out.println(sb.toString());
}
public static void main(String[] args){new Testing();}
}
?
How to Generate Words Randomly in Java
How to Add Buttons and
Text to Your JavaFX
Project
Making Your Page Layouts
Easier with Includes
Create a
Java
How to Generate Words Randomly in Java
By Barry Burd from Beginning Programming with Java For Dummies, 4th Edition
Most Java programs don’t work correctly the first time you run them, and some programs don’t work w
error on your part. This code is a case in point.
To write this code, you need a way to generate three­letter words randomly. This code would give you
anAccount.lastName = "" +
(char) (myRandom.nextInt(26) + 'A') +
(char) (myRandom.nextInt(26) + 'a') +
(char) (myRandom.nextInt(26) + 'a');
10 easy tricks to learn any
language from a man who
speaks 9
Promoted by Babbel
Unique Method May Regrow Lost
Hair
Promoted by Lifestyle Journal
Seven Foods That Fight
Inflammation and Belly Fat ­ For
Dummies
The
Plan
Sam
Wom
Random word from array list
while (line != null){
words.add(line);
//line = reader.readline();
}
}
public static void getRandomWord(){
Random rand = new Random();
String randomWord = words.get(rand.nextInt(words.size));
}
}
java random arraylist
asked Dec 3 '13 at 18:35
user3062703
1 1 1
– So you're trying to get a random word from a file and output it? Tatakai Wasumi Dec 3 '13 at 18:49
–
Member variables (e.g. 'words') cannot be referenced from static methods (e.g. 'getRandomWord()'). Either
declare 'words' as static or remove 'static' keyword from method signature. Hollis Waite Dec 3 '13 at
18:49
– you should use something like : int rand= minimum + (int)(Math.random()*maximum); Clad Clad Dec 3 '13
at 18:50
– Try this link maybe it will help you here Tatakai Wasumi Dec 3 '13 at 18:52
–
@TatakaiWasumi Indeed. From what I understand the first part of my code takes words from a file and puts
them in an arraylist. The second part of my code needs to generate a random number and from that, output
the corresponding word in the arraylist. I'm having issues with the fact that words is private... Says I can't
reach it from getRandomWord user3062703 Dec 3 '13 at 18:57
1 Answer
This will help you I think It's able to get a random word from an array of strings
private static String[] names = { "Terminator", "Slicer","Ninja", "cow", "Robot",
"littlegirl" };
Generating random words
of a certain length in java?
2 Answers
What kind of words do you want to generate? Random lowercase characters?
String getRandomWord(int length) {
want to generate? Random lowercase characters?
gth) { • In case the query is augmented, granularity is further
controlled since the structural code entities matched
• terms, excluding stop words, in the user free-form query
(cf. Figure 6(a)) are kept, after stemming, in the aug-
mented query (cf. Figure 6(c), lines Bissyande IxJ)
• structural code entities collected from Q&A snippets
(cf. Figure 6(b)) are mentioned with their type (e.g.,
non-qualified/partially qualified method invocation, or
class) in the augmented query (cf. Figure 6(c), lines Bissyande
IxJ)
To accelerate code query generation, CoCaBu builds on
an index of posts. Typically, Q&A forums provide archives
of their posts. These posts are often formatted by a struc-
tural language such as XML. For example, in Stack Over-
flow posts, code snippets are enclosed in <code> ...</code>.
As shown in Figure 8, our approach takes pre-downloaded
posts from a Q&A site and extracts metadata (post ID, ques-
tion title) and code snippets for each post. Each code snip-
pet is then analyzed to retrieve the structural code entities.
This phase presents challenges that will be addressed in Sec-
tion 3.1.
Q&A Posts
Code
Metadata
Post
Analyzer
Snippet
Index
pq_method_invocation:Random.nextInt
pq_method_invocation:Math.random
class:word class:char
class:int class:String
class:Random
instance:String
instance:Random
nq_method_invocation:nextInt
code:gener
code:random
code:word
...
Figure 7: Augmented query corresponding to the snippet shown
in Figure ??.
in Table 1:
• terms, excluding stop words, in the user free-form query
(cf. Figure 6(a)) are kept, after stemming, in the aug-
28

59. 27
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buf[i] = chars[random.nextInt(chars.length)];
}
return new String(buf);
Source: PasswordGenerator.java
Score: 34.5651054382
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"p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J",
"K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "0", "1", "2", "3",
"5", "6", "7", "8", "9" };
public static final Random random = new Random();
/**
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String password = "";
for (int i = 0; i < PASSWORD_LENGTH; i++)
{
password += CHARSET[random.nextInt(CHARSET.length)];
}
return password;
Source: RandomString.java
Score: 34.2108421326
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}
private final Random random = new Random();
private final char[] buf;
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public String nextString() {
for (int idx = 0; idx < buf.length; ++idx)
buf[idx] = symbols[random.nextInt(symbols.length)];
return new String(buf);
}
Title: Generating random words in Java?
Source: RandomString.java
Description: If you don't need English words, then something li
will do:
Score: 37.1969795227
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public class RandomString {
private static final char[] symbols = new char[36];
private static final Random random = new Random();
static {
37
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{
char[] buf = new char[length];
for (int idx = 0; idx < length; ++idx)
buf[idx] = symbols[random.nextInt(symbols.length)];
return new String(buf);
}
Title: Generating random words in Java?
Source: IdGenerator.java
Description: If you don't need English words, then something li
will do:
Score: 36.7602005005
3
4
public class IdGenerator {
Source: IdGenerator.java
Score: 36.7602005005
3
4
5
6
7
public class IdGenerator {
static final Random random = new Random();
static final char[] chars = new char[]
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private static String randomString(int length) {
char[] buf = new char[length];
for (int i=0; i<length; i++) {
buf[i] = chars[random.nextInt(chars.leng
}
return new String(buf);
Source: PasswordGenerator.java
y
y
-
,
h
t
e
y
r
s
-
e
arch proxy
ogram ele-
h.random),
d to match
ust extract
ded in the
turned by
generator
., answers
ery gener-
rch engine
How to create random string with random characters?
dling
ns
Util Package
tions
ns
s
Questions
Programs
eb Services
Program: How to create random string with random characters?
Description:
Write a program to generate random string of length 10 charactors. Every time you call the method, the
program should generate random string.
Code:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
package com.java2novice.random;
import java.util.Random;
public class MyStringRandomGen {
private static final String CHAR_LIST =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
private static final int RANDOM_STRING_LENGTH = 10;
/**
* This method generates random string
* @return
*/
public String generateRandomString(){
StringBuffer randStr = new StringBuffer();
for(int i=0; i<RANDOM_STRING_LENGTH; i++){
int number = getRandomNumber();
char ch = CHAR_LIST.charAt(number);
randStr.append(ch);
}
return randStr.toString();
}
/**
* This method generates random numbers
* @return int
*/
private int getRandomNumber() {
int randomInt = 0;
Random randomGenerator = new Random();
Be the first of your friends to like this
Java Sample Programs
7,256 likes
Like Page
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Random string generation
posted 10/13/2004 1:55 AM
posted 10/13/2004 2:15 AM
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place for
programming
greenhorns!
Big Moose Saloon
Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
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JavaRanch » Java Forums » Java » Java in General
Author Random string generation
Anna Hays
Ranch Hand
Joined: Nov 09, 2003
Posts: 131
Hi, can Java generate a string of random charactors? I need a password generation. Can someone give
me an idea of what's the proper way of doing this please? Thanks.
Michael Dunn
Ranch Hand
Joined: Jun 09, 2003
Posts: 4632
This might be one way
1
2
3
4
5
6
7
8
9
10
11
12
13
14
class Testing
{
public Testing()
{
final int PASSWORD_LENGTH = 8;
StringBuffer sb = new StringBuffer();
for (int x = 0; x < PASSWORD_LENGTH; x++)
{
sb.append((char)((int)(Math.random()*26)+97));
}
System.out.println(sb.toString());
}
public static void main(String[] args){new Testing();}
}
?
How to Generate Words Randomly in Java
How to Add Buttons and
Text to Your JavaFX
Project
Making Your Page Layouts
Easier with Includes
Create a
Java
How to Generate Words Randomly in Java
By Barry Burd from Beginning Programming with Java For Dummies, 4th Edition
Most Java programs don’t work correctly the first time you run them, and some programs don’t work w
error on your part. This code is a case in point.
To write this code, you need a way to generate three­letter words randomly. This code would give you
anAccount.lastName = "" +
(char) (myRandom.nextInt(26) + 'A') +
(char) (myRandom.nextInt(26) + 'a') +
(char) (myRandom.nextInt(26) + 'a');
10 easy tricks to learn any
language from a man who
speaks 9
Promoted by Babbel
Unique Method May Regrow Lost
Hair
Promoted by Lifestyle Journal
Seven Foods That Fight
Inflammation and Belly Fat ­ For
Dummies
The
Plan
Sam
Wom
Random word from array list
while (line != null){
words.add(line);
//line = reader.readline();
}
}
public static void getRandomWord(){
Random rand = new Random();
String randomWord = words.get(rand.nextInt(words.size));
}
}
java random arraylist
asked Dec 3 '13 at 18:35
user3062703
1 1 1
– So you're trying to get a random word from a file and output it? Tatakai Wasumi Dec 3 '13 at 18:49
–
Member variables (e.g. 'words') cannot be referenced from static methods (e.g. 'getRandomWord()'). Either
declare 'words' as static or remove 'static' keyword from method signature. Hollis Waite Dec 3 '13 at
18:49
– you should use something like : int rand= minimum + (int)(Math.random()*maximum); Clad Clad Dec 3 '13
at 18:50
– Try this link maybe it will help you here Tatakai Wasumi Dec 3 '13 at 18:52
–
@TatakaiWasumi Indeed. From what I understand the first part of my code takes words from a file and puts
them in an arraylist. The second part of my code needs to generate a random number and from that, output
the corresponding word in the arraylist. I'm having issues with the fact that words is private... Says I can't
reach it from getRandomWord user3062703 Dec 3 '13 at 18:57
1 Answer
This will help you I think It's able to get a random word from an array of strings
private static String[] names = { "Terminator", "Slicer","Ninja", "cow", "Robot",
"littlegirl" };
Generating random words
of a certain length in java?
2 Answers
What kind of words do you want to generate? Random lowercase characters?
String getRandomWord(int length) {
want to generate? Random lowercase characters?
gth) { • In case the query is augmented, granularity is further
controlled since the structural code entities matched
• terms, excluding stop words, in the user free-form query
(cf. Figure 6(a)) are kept, after stemming, in the aug-
mented query (cf. Figure 6(c), lines Bissyande IxJ)
• structural code entities collected from Q&A snippets
(cf. Figure 6(b)) are mentioned with their type (e.g.,
non-qualified/partially qualified method invocation, or
class) in the augmented query (cf. Figure 6(c), lines Bissyande
IxJ)
To accelerate code query generation, CoCaBu builds on
an index of posts. Typically, Q&A forums provide archives
of their posts. These posts are often formatted by a struc-
tural language such as XML. For example, in Stack Over-
flow posts, code snippets are enclosed in <code> ...</code>.
As shown in Figure 8, our approach takes pre-downloaded
posts from a Q&A site and extracts metadata (post ID, ques-
tion title) and code snippets for each post. Each code snip-
pet is then analyzed to retrieve the structural code entities.
This phase presents challenges that will be addressed in Sec-
tion 3.1.
Q&A Posts
Code
Metadata
Post
Analyzer
Snippet
Index
pq_method_invocation:Random.nextInt
pq_method_invocation:Math.random
class:word class:char
class:int class:String
class:Random
instance:String
instance:Random
nq_method_invocation:nextInt
code:gener
code:random
code:word
...
Figure 7: Augmented query corresponding to the snippet shown
in Figure ??.
in Table 1:
• terms, excluding stop words, in the user free-form query
(cf. Figure 6(a)) are kept, after stemming, in the aug-
(3) Searching for Code Examples
29