从头认识Spring-2.1 自动装配-byName
Posted 李灵晖
tags:
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这一章节我们来讨论一下自动装配的第一种方式-byName
我们还是以例子来说明:
1.domain
蛋糕类:(为了方便,只保留name属性以示区别)
package com.raylee.my_new_spring.my_new_spring.ch02.topic_1_1;
public class Cake {
private String name = "";
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
厨师类:
package com.raylee.my_new_spring.my_new_spring.ch02.topic_1_1;
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;
}
}
这里有一个注意点,就是Cake对象在注入的时候,会根据属性的名称来搜查,因此,这里的名字需要跟xml里面蛋糕Bean的id一样,这样才能在后面的测试里面顺利通过
2.测试类:
package com.raylee.my_new_spring.my_new_spring.ch02.topic_1_1;
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_1/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="cake"
class="com.raylee.my_new_spring.my_new_spring.ch02.topic_1_1.Cake"
p:name="blueberryCheeseCake" scope="prototype" />
<bean id="jack"
class="com.raylee.my_new_spring.my_new_spring.ch02.topic_1_1.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_1.Chief"
autowire="byName" p:name="rose" />
</beans>
在上面的配置文件里面我们需要注意的地方:
在rose里面,没有了cake属性的注入,但是增加了autowire="byName"这一句。
autowire="byName":表示当Bean的id跟注入属性的名称相一致的时候,即可注入,也就是,当rose里面有一个实现是cake,在配置文件里面只需要有一个bean的id是cake,那么,系统就会自动的把bean注入到属性里面去
测试输出:
jack make blueberryCheeseCake
rose make blueberryCheeseCake
总结:这一章节主要介绍了autowire属性里面的byName选项的使用。
目录:http://blog.csdn.net/raylee2007/article/details/50611627
我的github:https://github.com/raylee2015/my_new_spring
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