内部Bean、外部Bean和级联赋值

1 外部Bean

public class UserDao{
    
    
	private String username;
	public void SetName(String name){
    
    
		this.username = name;
	}
	public void add(){
    
    
		System.out.println("hello");
	}
}

public class UserService{
    
    
	private UserDao userdao;
	public void setUserdao(UserDao userdao){
    
    
		this.userdao = userdao;
	}
}

外部Bean的注入：

<bean id = "userService" class="com.glp.UserService">
	<property name = "userDao" ref ="userDao"></property>
</bean>

<bean id = "userDao" class="com.glp.UserDao"></bean>

2 内部Bean

内部Bean的注入：

<bean id = "userService" class="com.glp.UserService">
	<property name = "userDao">
		<bean id = "userDao" class="com.glp.UserDao">
			<property name = "username" value="glp"></property>
		</bean>
	</property>
</bean>

3 级联赋值

和外部Bean有些区别，在引入外部Bean的同时，给外部Bean设置了属性。

<bean id = "userService" class="com.glp.UserService">
	<property name = "userDao" ref="userDao"></property>
</bean>

<bean id = "userDao" class="com.glp.UserDao">
	<property name = "username" value="glp"></property>
</bean>