spring的两种属性注入方式

Spring包下载地址：http://repo.spring.io/release/org/springframework/spring/

 

1.set方式注入

配置文件：

<?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:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">
<!-- 使用set方法注入属性 
    singleton 单实例 默认
    prototype 多实例

-->
<bean id="user" class="com.spring.demo1.User" scope="singleton">
<!-- 注入属性值 
name的属性值就是类里面定义的属性名称
value设置具体值
-->
<property name="bookname" value="程序设计"></property>
</bean>
</beans>

测试代码：

package com.spring.demo1;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class TestIOC {
    public static void main(String[] args) {

        //1.加载spring配置文件，根据配置创建对象
        ApplicationContext context = (ApplicationContext) new ClassPathXmlApplicationContext("config.xml");
        //2.得到配置创建的对象
        User user=(User) context.getBean("user");//强转，引号内为配置文件中的id名
        User user1=(User) context.getBean("user");
        System.out.println(user);//单实例输出地址
        System.out.println(user1);//多实例输出地址不一样
        user.add();//方法调用
    }
}

package com.spring.demo1;

public class User {
private String bookname;
//只需要构造一个set方法
public void setBookname(String bookname) {
this.bookname = bookname;
    }

public void add(){
            System.out.println("bookname......"+bookname);
        }

}

测试结果：

 

 

 

 

2.有参构造注入

配置文件：

<?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:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">

<bean id="HelloWorld" class="com.gc.action.HelloWorld">

<!-- 有参构造注入 -->
<constructor-arg index="0">
        <value>HelloWorld1</value>
</constructor-arg>
</bean>
</beans>

测试代码：

package com.gc.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.gc.action.HelloWorld;

public class TestHelloWorld {
public static void main(String[] args) {
            ApplicationContext actx=(ApplicationContext) new ClassPathXmlApplicationContext("applicationContext.xml");
            HelloWorld helloworld=(HelloWorld) actx.getBean("HelloWorld");
            System.out.println(helloworld.getMsg());
        }
}

package com.gc.action;

public class HelloWorld {
public String msg=null;


//添加构造方法实现构造注入
public HelloWorld(String msg) {
            super();
this.msg = msg;
        }

public String getMsg() {
return msg;
        }

public void setMsg(String msg) {
this.msg = msg;
        }

}

结果：

 新看了一个P名称空间注入：

config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- 引入p名称空间  ，最后以p结尾-->
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">
<!-- p名称空间注入 -->
<bean id="person" class="com.spring.property.Person" p:name="lucy"></bean>
</beans>

Person.java

package com.spring.property;

public class Person {
private String name;

public void setName(String name) {
this.name = name;
        }
public void test1(){
            System.out.println("person"+name);
        }
}

Testp.java

package com.spring.property;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Testp {
public static void main(String[] args) {
            ApplicationContext context=new ClassPathXmlApplicationContext("config.xml");
            Person person=(Person) context.getBean("person");
            person.test1();
        }
}

测试结果：