Sping之bean对象注入

1.set方法注入

我们在service中通过set方法注入UserDao对象

  
private UserDao userDao;
public void setUserDao(UserDao userDao) {
      this.userDao = userDao;
  }

然后在xml中

  <bean id="userService" class="com.wjb.service.impl.UserServiceImpl">
      <property name="userDao" ref="userDao"/>
  </bean>

 

2.有参构造方法注入

service中

public UserServiceImpl(UserDao userDao) {
        this.userDao = userDao;
    }

    public UserServiceImpl() {
    }

    private UserDao userDao;

然后在xml中

 <bean id="userService" class="com.wjb.service.impl.UserServiceImpl">
           <constructor-arg name="userDao" ref="userDao"></constructor-arg>
    </bean>