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1. 默认按类型 by type, 如果想用byname, 使用@Qualifier
2. 如果写在set上, @qualifier需要写在参数上
bean.xml:
默认bytype去找set方法, 注入
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-2.5.xsd">
<context:annotation-config />
<bean id="u" class="com.bjsxt.dao.impl.UserDAOImpl">
</bean>
<bean id="userService" class="com.bjsxt.service.UserService" >
</bean>
</beans>
在set方法上加入@AutoWired:
package com.bjsxt.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.User;
public class UserService {
private UserDAO userDAO;
public void init() {
System.out.println("init");
}
public void add(User user) {
userDAO.save(user);
}
public UserDAO getUserDAO() {
return userDAO;
}
@Autowired
public void setUserDAO(UserDAO userDAO) {
this.userDAO = userDAO;
}
public void destroy() {
System.out.println("destroy");
}
}
如果bytype找到2个bean , 参考下面的xml文件,可以在service文件里再加入@Qualifier标识符,
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-2.5.xsd">
<context:annotation-config />
<bean id="u" class="com.bjsxt.dao.impl.UserDAOImpl">
</bean>
<bean id="u2" class="com.bjsxt.dao.impl.UserDAOImpl">
</bean>
<bean id="userService" class="com.bjsxt.service.UserService" >
</bean>
</beans>
UserService.java:
package com.bjsxt.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.User;
public class UserService {
private UserDAO userDAO;
public void init() {
System.out.println("init");
}
public void add(User user) {
userDAO.save(user);
}
public UserDAO getUserDAO() {
return userDAO;
}
@Autowired
public void setUserDAO(@Qualifier("u") UserDAO userDAO) {
this.userDAO = userDAO;
}
public void destroy() {
System.out.println("destroy");
}
}
Spring ---annotation (重点)--AutoWired 不常用
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原文地址：http://www.cnblogs.com/wujixing/p/5454204.html
