从头认识Spring-2.1 自己主动装配-byType

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为了解决配置文件中面出现多个同类型的Bean而byType无法匹配的问题。引入了primary和autowire-candidate属性。

1.primary

因为全部bean默认的primary都是true。因此笔者觉得这个属性没有太大的用处


2.autowire-candidate

这个属性的意思是,是否排除自己,假设排除了自己。 那么当使用byType的时候,这个Bean就不列入候选bean里面。看以下的样例:


(1)domain

蛋糕类:(不变)

package com.raylee.my_new_spring.my_new_spring.ch02.topic_1_3;

public class Cake {
	
	private String name = "";

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

}

厨师类:(不变)

package com.raylee.my_new_spring.my_new_spring.ch02.topic_1_3;

public class Chief {
	private Cake cake = null;

	private String name = "";

	public Cake getCake() {
		return cake;
	}

	public String getName() {
		return name;
	}

	public Cake makeOneCake() {
		System.out.println(getName() + " make " + getCake().getName());
		return cake;
	}

	public void setCake(Cake cake) {
		this.cake = cake;
	}

	public void setName(String name) {
		this.name = name;
	}

}

(2)測试类:(不变)

package com.raylee.my_new_spring.my_new_spring.ch02.topic_1_3;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {
		"/com/raylee/my_new_spring/my_new_spring/ch02/topic_1_3/ApplicationContext-test.xml" })
public class ChiefTest {

	@Autowired
	private ApplicationContext applicationContext;

	@Test
	public void testChief() {
		Chief jack = (Chief) applicationContext.getBean("jack");
		jack.makeOneCake();
		Chief rose = (Chief) applicationContext.getBean("rose");
		rose.makeOneCake();
	}
}

(3)配置文件:(重点)

<?

xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:util="http://www.springframework.org/schema/util" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> <bean id="blueberryCheeseCake" class="com.raylee.my_new_spring.my_new_spring.ch02.topic_1_3.Cake" p:name="blueberryCheeseCake" scope="prototype" /> <bean id="cake" class="com.raylee.my_new_spring.my_new_spring.ch02.topic_1_3.Cake" p:name="cake" scope="prototype" autowire-candidate="false" /> <bean id="jack" class="com.raylee.my_new_spring.my_new_spring.ch02.topic_1_3.Chief" p:name="jack"> <property name="cake" ref="cake" /> </bean> <bean id="rose" class="com.raylee.my_new_spring.my_new_spring.ch02.topic_1_3.Chief" autowire="byType" p:name="rose" /> </beans>


上面的配置文件使用autowire-candidate排除了cake这个bean,因此会出现以下的输出。


測试输出:

jack make cake
rose make blueberryCheeseCake


总结:这一章节主要介绍解决配置文件中面出现多个同类型的Bean而byType无法匹配的问题。


文件夹:http://blog.csdn.net/raylee2007/article/details/50611627 

 

我的github:https://github.com/raylee2015/my_new_spring


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