Spring3.2.2_自动安装

Spring3.2.2_自动装配

分类：?Spring课程总结2013-04-25 16:33?157人阅读?评论(0)?收藏?举报

Spring_Autowiring?collaborators

在Spring3.2.2中自动装配类型，分别为：no(default)(不采用自动装配)、byName，byType，constructor下面来分别介绍一下这些是如何自动装配的

???<bean?id="foo"?style="font-family: Consolas, 'Courier New', Courier, mono, serif; font-size: 12px; background-color: #e7e5dc; width: 693px; overflow: auto; padding-top: 1px; color: #362e2b; margin: 18px 0px !important;">[java]?view plaincopy?

1. package?www.csdn.spring.autowire.bean;??
2. ??
3. public?class?CumputerBean?{??
4. ??
5. //?电脑名称??
6. ??
7. private?String?name;??
8. ??
9. public?void?setName(String?name)?{??
10. ??
11. this.name?=?name;??
12. ??
13. }??
14. ??
15. }??

2、创建DeptBean?类

[java]?view plaincopy?

1. package?www.csdn.spring.autowire.bean;??
2. ??
3. ??
4. public?class?DeptBean?{??
5. ??
6. //部门名称??
7. ??
8. private?String?name;??
9. ??
10. public?void?setName(String?name)?{??
11. ??
12. this.name?=?name;??
13. ??
14. }??
15. ??
16. }??

3、创建EmployeeBean

[java]?view plaincopy?

1. package?www.csdn.spring.autowire.bean;??
2. ??
3. ??
4. public?class?EmployeeBean?{??
5. ??
6. private?DeptBean?deptBean;??
7. ??
8. private?CumputerBean?cumputerBean;??
9. ??
10. ??
11. public?void?setDeptBean(DeptBean?deptBean)?{??
12. ??
13. this.deptBean?=?deptBean;??
14. ??
15. }??
16. ??
17. public?void?setCumputerBean(CumputerBean?cumputerBean)?{??
18. ??
19. this.cumputerBean?=?cumputerBean;??
20. ??
21. }??
22. ??
23. @Override??
24. ??
25. public?String?toString()?{??
26. ??
27. return?"EmployeeBean?[deptBean="?+?deptBean?+?",?cumputerBean="??
28. ??
29. +?cumputerBean?+?"]";??
30. ??
31. }??
32. ??
33. ??
34. }??

首先分析no、byName、byType的配置都是采用setter方法依赖注入实现的案例

1、no配置（通过ref=””引用需要的bean）

[java]?view plaincopy?

1. <?xml?version="1.0"?encoding="UTF-8"?>??
2. ??
3. <beans?xmlns="http://www.springframework.org/schema/beans"??
4. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"??
5. xsi:schemaLocation="http://www.springframework.org/schema/beans??
6. ???????????http://www.springframework.org/schema/beans/spring-beans.xsd">??
7. ??
8. <!--?电脑bean?-->??
9. <bean?id="cumputerBean"?class="www.csdn.spring.autowire.bean.CumputerBean">??
10. <property?name="name"?value="HP6325笔记本"?/>??
11. </bean>??
12. ??
13. <!--?部门bean?-->??
14. <bean?id="deptBean"?class="www.csdn.spring.autowire.bean.DeptBean">??
15. <property?name="name"?value="CSDN教育事业部"?/>??
16. </bean>??
17. ??
18. <!--?员工bean??根据EmployeeBean中的属性名称通过ref="bean"去匹配-->??
19. <bean?id="employeeBean"?class="www.csdn.spring.autowire.bean.EmployeeBean">??
20. <property?name="cumputerBean"?ref="cumputerBean"?/>??
21. <property?name="deptBean"?ref="deptBean"?/>??
22. ??
23. </bean>??
24. ??
25. </beans>??

2、byName配置(分析:会根据EmployeeBean中属性的名称?自动装配)

[java]?view plaincopy?

1. <?xml?version="1.0"?encoding="UTF-8"?>??
2. ??
3. <beans?xmlns="http://www.springframework.org/schema/beans"??
4. ??
5. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"??
6. ??
7. xsi:schemaLocation="http://www.springframework.org/schema/beans??
8. ??
9. ???????????http://www.springframework.org/schema/beans/spring-beans.xsd">??
10. ??
11. ??
12. ??
13. <!--?电脑bean?-->??
14. ??
15. <bean?id="cumputerBean"?class="www.csdn.spring.autowire.bean.CumputerBean">??
16. ??
17. <property?name="name"?value="HP6325笔记本"?/>??
18. ??
19. </bean>??
20. ??
21. <!--?部门bean?-->??
22. ??
23. <bean?id="deptBean"?class="www.csdn.spring.autowire.bean.DeptBean">??
24. ??
25. <property?name="name"?value="CSDN教育事业部"?/>??
26. ??
27. </bean>??
28. ??
29. <!--?员工bean-->??
30. ??
31. <bean?id="employeeBean"?class="www.csdn.spring.autowire.bean.EmployeeBean"?autowire="byName"/>??
32. ??
33. </beans>??

[java]?view plaincopy?

1. ???

3、byType配置(分析:会根据EmployeeBean中属性的类型?自动装配)

[java]?view plaincopy?

1. <?xml?version="1.0"?encoding="UTF-8"?>??
2. ??
3. <beans?xmlns="http://www.springframework.org/schema/beans"??
4. ??
5. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"??
6. ??
7. xsi:schemaLocation="http://www.springframework.org/schema/beans??
8. ??
9. ???????????http://www.springframework.org/schema/beans/spring-beans.xsd">??
10. ??
11. <!--?电脑bean?-->??
12. ??
13. <bean?id="cumputerBean"?class="www.csdn.spring.autowire.bean.CumputerBean">??
14. ??
15. <property?name="name"?value="HP6325笔记本"?/>??
16. ??
17. </bean>??
18. ??
19. <!--?部门bean?-->??
20. ??
21. <bean?id="deptBean"?class="www.csdn.spring.autowire.bean.DeptBean">??
22. ??
23. <property?name="name"?value="CSDN教育事业部"?/>??
24. ??
25. </bean>??
26. ??
27. <!--?员工bean??根据EmployeeBean中的属性根据类型匹配-->??
28. ??
29. <bean?id="employeeBean"?class="www.csdn.spring.autowire.bean.EmployeeBean"?autowire="byType"/>??
30. ??
31. ??
32. </beans>??

注意：当根据byType类型装配时，当在容器内找到多个匹配的类型时会出现如下bug

org.springframework.beans.factory.UnsatisfiedDependencyException:?

Error?creating?bean?with?name?'employeeBean'?defined?in?class?path?resource?[spring-byType.xml]:?Unsatisfied?dependency?expressed?through?bean?property?'deptBean':?:

?No?qualifying?bean?of?type?[www.csdn.spring.autowire.bean.DeptBean]?is?defined:?expected?single?matching?bean?but?found?2:?deptBean,deptBean1;?

nested?exception?is?org.springframework.beans.factory.NoUniqueBeanDefinitionException:?

No?qualifying?bean?of?type?[www.csdn.spring.autowire.bean.DeptBean]?is?defined:?expected?single?matching?bean?but?found?2:?deptBean,deptBean1

?

4、Constructor(构造器参数根据byType类型匹配，自动装配)

首先修改EmployeeBean类?修改后代码如下：

[java]?view plaincopy?

1. package?www.csdn.spring.autowire.bean;??
2. ??
3. ??
4. public?class?EmployeeBean?{??
5. ??
6. private?DeptBean?deptBean;??
7. private?CumputerBean?cumputerBean;??
8. ??
9. ??
10. public?EmployeeBean(DeptBean?deptBean,?CumputerBean?cumputerBean)?{??
11. super();??
12. this.deptBean?=?deptBean;??
13. this.cumputerBean?=?cumputerBean;??
14. }??
15. ??
16. @Override??
17. public?String?toString()?{??
18. return?"EmployeeBean?[deptBean="?+?deptBean?+?",?cumputerBean="??
19. +?cumputerBean?+?"]";??
20. }??
21. }??

[java]?view plaincopy?

1. ???

配置文件操作：

[html]?view plaincopy?

1. ??<?xml?version="1.0"?encoding="UTF-8"?>??
2. ??
3. <beans?xmlns="http://www.springframework.org/schema/beans"??
4. ??
5. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"??
6. ??
7. xsi:schemaLocation="http://www.springframework.org/schema/beans??
8. ??
9. ???????????http://www.springframework.org/schema/beans/spring-beans.xsd">??
10. ??
11. <!--?电脑bean?-->??
12. ??
13. <bean?id="cumputerBean"?class="www.csdn.spring.autowire.bean.CumputerBean">??
14. <property?name="name"?value="HP6325笔记本"?/>??
15. </bean>??
16. ??
17. <!--?部门bean?-->??
18. ??
19. <bean?id="deptBean"?class="www.csdn.spring.autowire.bean.DeptBean">??
20. <property?name="name"?value="CSDN教育事业部"?/>??
21. </bean>??
22. ??
23. <!--?员工bean?根据EmployeeBean中的?属性名称?bytype?去匹配?-->??
24. <bean?id="employeeBean"?class="www.csdn.spring.autowire.bean.EmployeeBean"??
25. autowire="constructor">??
26. </bean>??
27. ??
28. </beans>??

说明:

1、当构造器的参数类型在容器中找不全时。

?比如：

???配置文件中只配置了CumpterBean时

?

??

[html]?view plaincopy?

1. <?xml?version="1.0"?encoding="UTF-8"?>??
2. ??
3. <beans?xmlns="http://www.springframework.org/schema/beans"??
4. ??
5. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"??
6. ??
7. xsi:schemaLocation="http://www.springframework.org/schema/beans??
8. ??
9. ???????????http://www.springframework.org/schema/beans/spring-beans.xsd">??
10. ??
11. <!--?电脑bean?-->??
12. ??
13. <bean?id="cumputerBean"?class="www.csdn.spring.autowire.bean.CumputerBean">??
14. ??
15. <property?name="name"?value="HP6325笔记本"?/>??
16. ??
17. </bean>??
18. ??
19. <!--?员工bean?根据EmployeeBean中的?属性名称?bytype?去匹配?-->??
20. ??
21. <bean?id="employeeBean"?class="www.csdn.spring.autowire.bean.EmployeeBean"??
22. ??
23. autowire="constructor">??
24. ??
25. </bean>??
26. ??
27. </beans>??

[html]?view plaincopy?

1. ???

会出现如下bug:

org.springframework.beans.factory.UnsatisfiedDependencyException:

?Error?creating?bean?with?name?'employeeBean'?defined?in?class?path?resource?[spring-constructors.xml]:?Unsatisfied?dependency?expressed?through?constructor?argument?with?index?0?of?type?[www.csdn.spring.autowire.bean.DeptBean]:?:?

No?qualifying?bean?of?type?[www.csdn.spring.autowire.bean.DeptBean]?found?for?dependency:

?expected?at?least?1?bean?which?qualifies?as?autowire?candidate?for?this?dependency.?Dependency?annotations:?{};?

nested?exception?is?org.springframework.beans.factory.NoSuchBeanDefinitionException:

?No?qualifying?bean?of?type?[www.csdn.spring.autowire.bean.DeptBean]?found?for?dependency:?

expected?at?least?1?bean?which?qualifies?as?autowire?candidate?for?this?dependency.?Dependency?annotations:?{}

Caused?by:?

org.springframework.beans.factory.NoSuchBeanDefinitionException:

?No?qualifying?bean?of?type?[www.csdn.spring.autowire.bean.DeptBean]?found?for?dependency:?

expected?at?least?1?bean?which?qualifies?as?autowire?candidate?for?this?dependency.?Dependency?annotations:?{}

2、当配置文件找到构造器参数的类型有多个的时候比如配置文件如下：

[html]?view plaincopy?

1. <?xml?version="1.0"?encoding="UTF-8"?>??
2. ??
3. <beans?xmlns="http://www.springframework.org/schema/beans"??
4. ??
5. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"??
6. ??
7. xsi:schemaLocation="http://www.springframework.org/schema/beans??
8. ??
9. ???????????http://www.springframework.org/schema/beans/spring-beans.xsd">??
10. ??
11. <!--?电脑bean?-->??
12. ??
13. <bean?id="cumputerBean"?class="www.csdn.spring.autowire.bean.CumputerBean">??
14. ??
15. <property?name="name"?value="HP6325笔记本"?/>??
16. ??
17. </bean>??
18. ??
19. <!--?部门bean?-->??
20. ??
21. <bean?id="deptBean"?class="www.csdn.spring.autowire.bean.DeptBean">??
22. ??
23. <property?name="name"?value="CSDN教育事业部"?/>??
24. ??
25. </bean>??
26. ??
27. <!--?部门bean?-->??
28. ??
29. <bean?id="deptBean1"?class="www.csdn.spring.autowire.bean.DeptBean">??
30. ??
31. <property?name="name"?value="CSDN教育事业部"?/>??
32. ??
33. </bean>??
34. ??
35. ??
36. <!--?员工bean?根据EmployeeBean中的?属性名称?bytype?去匹配?-->??
37. ??
38. <bean?id="employeeBean"?class="www.csdn.spring.autowire.bean.EmployeeBean"??
39. ??
40. autowire="constructor">??
41. ??
42. </bean>??
43. ??
44. </beans>??

?

说明：上面配置有两个同样类型的DeptBean但是不会出现bug，原因是在EmployeeBean中构造器接受的参数名称与deptBean一致。

3、当配置文件找到构造器参数的类型有多个的时候比如配置文件如下：

[html]?view plaincopy?

1. <?xml?version="1.0"?encoding="UTF-8"?>??
2. ??
3. <beans?xmlns="http://www.springframework.org/schema/beans"??
4. ??
5. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"??
6. ??
7. xsi:schemaLocation="http://www.springframework.org/schema/beans??
8. ??
9. ???????????http://www.springframework.org/schema/beans/spring-beans.xsd">??
10. ??
11. <!--?电脑bean?-->??
12. ??
13. <bean?id="cumputerBean"?class="www.csdn.spring.autowire.bean.CumputerBean">??
14. ??
15. <property?name="name"?value="HP6325笔记本"?/>??
16. ??
17. </bean>??
18. ??
19. <!--?部门bean?-->??
20. ??
21. <bean?id="deptBean1"?class="www.csdn.spring.autowire.bean.DeptBean">??
22. ??
23. <property?name="name"?value="CSDN教育事业部"?/>??
24. ??
25. </bean>??
26. ??
27. <!--?部门bean?-->??
28. ??
29. <bean?id="deptBean2"?class="www.csdn.spring.autowire.bean.DeptBean">??
30. ??
31. <property?name="name"?value="CSDN教育事业部"?/>??
32. ??
33. </bean>??
34. ??
35. <!--?员工bean?根据EmployeeBean中的?属性名称?bytype?去匹配?-->??
36. ??
37. <bean?id="employeeBean"?class="www.csdn.spring.autowire.bean.EmployeeBean"??
38. ??
39. autowire="constructor">??
40. ??
41. </bean>??
42. ??
43. </beans>??

会出现如下bug（与byType的bug一致）:

[java]?view plaincopy?

1. org.springframework.beans.factory.UnsatisfiedDependencyException:???
2. ??
3. Error?creating?bean?with?name?'employeeBean'?defined?in?class?path?resource?[spring-constructors.xml]:??

[java]?view plaincopy?

1. Unsatisfied?dependency?expressed?through?constructor?argument?with?index?0?of?type?[www.csdn.spring.autowire.bean.DeptBean]:?:???
2. ??
3. No?qualifying?bean?of?type?[www.csdn.spring.autowire.bean.DeptBean]?is?defined:???
4. ??
5. expected?single?matching?bean?but?found?2:?deptBean1,deptBean2;???
6. ??
7. nested?exception?is?org.springframework.beans.factory.NoUniqueBeanDefinitionException:??
8. ??
9. ?No?qualifying?bean?of?type?[www.csdn.spring.autowire.bean.DeptBean]?is?defined:???

[java]?view plaincopy?

1. expected?single?matching?bean?but?found?2:?deptBean1,deptBean2??