의존성 주입(Dependency Injection)의 개념을 설명하기 위해 만든 강의자료입니다. 의존성 주입이 어떤 방식으로 객체간의 커플링을 느슨하게 만드는지를 설명하고 있습니다.

1. Java

2. Web

4.
Programming

5. Advanced

7.
Week01

8.
Dependency
Injection
의존성

9. 주입

10.
조영호

11.
snatcher@nhn.com

13. Dependency

15. Dependency

16.
변경

18. Dependency in OO

19.
Method
Call

20.
Object A

21. Object B

22.
Object A

23. Object B

24. depends on

26. in Code

27.
public class MovieLister {
public ListMovie findAll() {
...
}
}
public class MovieFinder {
private MovieLister lister;
public void moviesDirectedBy(String title) {
ListMovie allMovies = lister.findAll();
...
}
}
Dependency

29. class Lecture Class Standard
Grader
Dependency
C o d e Rev i ew

31. C o d e Rev i ew

32.
class Lecture Class Standard
Grader
Dependency
Class PassFail
Grader

33. Coupling결합도

34.
= Coupling

35.
Object A

36. Object B

37.
Dependency

39. = Coupling

40.
Object A

41. Object B

42.
Dependency

43.
Coupling은

44. 반드시

45. 필요

46.
OO의

47. 기반은

49. 객체와

50. 객체

51. 간의

52. 메시지

53. 전송

55. Goal

56.
의존성을

57. 없애는

58. 것이

59. 아니라

60.
결합도를

61. 낮추는

62. 것

63.
= Coupling

64.
Object A

65. Object B

66.
Dependency

68. Tight Coupling?

69.
대상에

70. 대해

72.
더

73. 많이

74. 가정해야하는

75. 것

77. class Lecture Class Standard
Grader
Dependency
P ro bl e m

78.
Class
Dependency

79. P ro bl e m

80.
class Lecture Class Standard
Grader
Dependency
Class PassFail
Grader
Class 대상

81. 수정

82. P ro bl e m

83.
class Lecture Class Standard
Grader
Dependency
Class PassFail
Grader
Tight Coupling
Dependency

84. S o l u t i o n

85.
class Lecture
Class Standard
Grader
Class PassFail
Grader
Dependency
Abstraction
Loose Coupling

86. S o l u t i o n

87.
class Lecture
Class Standard
Grader
Class PassFail
Grader
Dependency
Abstract
Class
interface
Loose Coupling

88. S o l u t i o n

89.
class Lecture
Dependency
Abstract
Class
interface
Loose Coupling
클래스에

90. 대한

91. 가정

92. 제거

93.
단지

94. 행위에

95. 대해서만

96. 가정

98. Interface?
Discussion

99. Behavior
Discussion

100. class Lecture
grade()
Lecture의

101. 입장에서

103.
Grade를

104. 산출하는

105. 동일한

106. 행위를

107. 제공하는

109.
모든

110. 객체와

111. 협력

112. 가능

113.
Discussion
class
class
class

114. class Lecture
grade()
Lecture의

115. 입장에서

117.
Grade를

118. 산출하는

119. 동일한

120. 인터페이스를

121. 제공하는

123.
모든

124. 객체와

125. 협력

126. 가능

127.
Discussion
class
class
class

128. class Lecture
grade()
Lecture는

130.
다양한

131. 객체들과

132. 협력

133. 가능

134.
Discussion
class
class
class

135. class Lecture
grade()
Lecture는

137.
다양한

138. 객체들과

139. 협력

140. 가능하기

141. 때문에

143.
설계가

144. 유연함

145.
Discussion
class
class
class

146. class Lecture
grade()
Lecture는

148.
다양한

149. 상황에서

150.
재사용이

151. 가능

152.
Discussion
class
class
class

153. class Lecture
grade()
단,

154. Lecture가

156.
구체적인

157. 클래스와

158. 결합되면

160.
위에서

161. 나열한

162. 장점을

163. 누릴

164. 수

165. 없음

166.
Discussion
class
class
class

167. class Lecture
grade()
Lecture는

169.
구체적인

170. 클래스가

171. 아니라

172.
행위에만

173. 의존해야

174. 함

175.
Discussion
class
class
class

176. Program to an interface,
not implementation

177. class Lecture
grade()
Java
interface
Discussion
class
class
class
interface

178. Refactoring

179. P ro bl e m

180.
class
Lecture
Class
StandardGrader
Class
PassFailGrader
interface
Grader
Create
Dependency
Dependency
Use
Tight Coupling
Class
Dependency

181. S o l u t i o n

182.
class
Lecture
Class
StandardGrader
Class
PassFailGrader
interface
Grader
Create
Dependency
Dependency
Use
Separate Use From Construction

183. S o l u t i o n

184.
class
Lecture
Class
StandardGrader
Class
PassFailGrader
interface
Grader
Create
Dependency
Dependency
Use
Client
Dependency
Use
Separate Use From Construction

185. S o l u t i o n

186.
class
Lecture
Class
StandardGrader
Class
PassFailGrader
interface
Grader
Dependency
Use
Client
Dependency
Use
Separate Use From Construction
Create
Dependency

187. S o l u t i o n

188.
class
Lecture
Class
StandardGrader
Class
PassFailGrader
interface
Grader
Dependency
Use
Client
Dependency
Use
Separate Use From Construction
Create
Dependency
inject
Dependency

189. Refactoring

190. Lecture lecture = new Lecture(new StandardGrader(),
80, 90, 65);
String grade = lecture.grade();
Lecture lecture = new Lecture(new PassFailGrader(),
80, 90, 65);
String grade = lecture.grade();
Lecture의 Client가
Lecture가 사용할(Use)
Grader를 생성(Create)한 후
Lecture에게 주입
(Dependency Injection)

191. Program to an interface,
not implementation
Dependency
Injection

192. Lecture lecture = new Lecture(new StandardGrader(),
80, 90, 65);
String grade = lecture.grade();
Lecture lecture = new Lecture(new PassFailGrader(),
80, 90, 65);
String grade = lecture.grade();
Lecture를

193. 사용하는

194. 모든

195. 곳에서

197.
이런

198. 일을

199. 하기

200. 귀찮겠죠?

202. S o l u t i o n

203.
class
Lecture
Class
StandardGrader
Class
PassFailGrader
interface
Grader
Dependency
Use
Client
Dependency
Use
Dependency Injection Framework
inject
Dependency

204. Spring

205.
@Controller
public class ManageBookController {
@Autowired
private BookstoreService bookstoreService;
@Autowired
private CategoryService categoryService;

206. Dependency Injection
Interface
Discussion
Flexibility
Testability
Reusability

207. Interface
Dynamic Type
Language
Discussion

208. class Lecture:
def __init__(self, grader, scores):
self.scores = scores
self.grader = grader
def grade(self):
return self.grader.grade(self.scores)
class StandardGrader:
def grade(self):
...
class PassFailGrader:
def grade(self):
...
ex) Python