Spring三种注入方式（二）-优快云博客

本文介绍如何使用Spring框架通过访问器方法(set)实现依赖注入。具体展示了Source和Target两个类的定义及配置文件applicationContext.xml的设置，并通过TargetTest进行验证。

通过访问器方法(set)注入

此方法较为常用.在目标类中,定义要注入的属性,并添加访问器方法,则spring会自动注入.

Source.java

package com.gary.test;

public class Source {
	
	public void helloWorld(){
		System.out.println("Hello World!");
	}
}

Target.java

package com.gary.test;

public class Target {
	
	private Source source;

	public void setSource(Source source) {
		this.source = source;
	}

	public Source getSource() {
		return source;
	}
	
	public void sayHelloWorld(){
		getSource().helloWorld();
	}
	
}

applicationContext.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"
	xmlns:p="http://www.springframework.org/schema/p"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"
	default-autowire="byType">

	<bean id="source" class="com.gary.test.Source" />
	<bean id="target" class="com.gary.test.Target">
		<!-- 在beans标签添加default-autowire="byType"属性后,下面这行可以省略  -->
		<!-- <property name="source" ref="source" /> -->
	</bean>
</beans>

TargetTest.java

package com.gary.test;

import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TargetTest {

	static BeanFactory factory = null;
	static Target target = null;
	
	@BeforeClass
	public static void setUpBeforeClass() throws Exception {
		try{
			factory = new ClassPathXmlApplicationContext("applicationContext.xml");
			target = (Target) factory.getBean("target");
		}catch(Exception e){
			e.printStackTrace();
		}
	}

	@AfterClass
	public static void tearDownAfterClass() throws Exception {
		
	}

	@Test
	public void testSayHelloWorld() {
		target.sayHelloWorld();
	}

}

运行结果

Hello World!

源码见附件