spring入門（6） set方法注入依賴之null的注入

Member.java

package www.csdn.spring.constructor.bean;  
      
public class Member {  
      
}

MemberBean.java

package www.csdn.spring.constructor.bean;  
      
public class MemberBean {  
      
    public String name;  
      
    public Member member;  
      
    public void setMember(Member member) {  
        this.member = member;  
    }  
      
    public void setName(String name) {  
        this.name = name;  
    }  
      
}

spring-null.xml

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans  
           http://www.springframework.org/schema/beans/spring-beans.xsd">  
      
    <bean id="memberBean" class="www.csdn.spring.constructor.bean.MemberBean">  
        <!-- value="null" null是字符串 -->
        <property name="name">  
            <null  />  
        </property>  
        <property name="member">  
            <null  />  
        </property>  
    </bean>  
      
</beans>

MemberTest.java

package www.csdn.spring.constructor.bean;  
      
import org.junit.Test;  
import org.springframework.context.ApplicationContext;  
import org.springframework.context.support.ClassPathXmlApplicationContext;  
      
public class MemberTest {  
      
          
    @Test
    public void testBean(){  
        ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring-null.xml");  
              
        MemberBean bean = context.getBean("memberBean", MemberBean.class);  
              
        System.out.println(bean.name);  
        System.out.println(bean.member);  
    }  
}

控制台輸出：

null

null

它們代表空值