自动装配byType即通过查找类属性在配置文件中bean中定义的class属性来注入,而不是通过类属性名与配置文件中bean的id属性来匹配的。
如下例:
package com.lwf.bean; public class Bean2 { private Bean3 bean3; private Bean4 bean4; private Bean5 bean5; public Bean3 getBean3() { return bean3; } public void setBean3(Bean3 bean3) { this.bean3 = bean3; } public Bean4 getBean4() { return bean4; } public void setBean4(Bean4 bean4) { this.bean4 = bean4; } public Bean5 getBean5() { return bean5; } public void setBean5(Bean5 bean5) { this.bean5 = bean5; } }
package com.lwf.bean; import java.util.Date; public class Bean3 { private int id; private String name; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
package com.lwf.bean; public class Bean4 { private int id; private String name; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
package com.lwf.bean; public class Bean5 { private int age; public int getAge() { return age; } public void setAge(int age) { this.age = age; } }
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:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd" default-autowire="byType" > <bean id="bean2" class="com.lwf.bean.Bean2"/> <bean id="bean5ref" class="com.lwf.bean.Bean5"> <property name="age" value="33"></property> </bean> <bean id="parentBean" abstract="true"> <property name="id" value="1"/> <property name="name" value="zhang"/> </bean> <bean id="bean3ref" class="com.lwf.bean.Bean3" parent="parentBean"/> <bean id="bean4ref" class="com.lwf.bean.Bean4" parent="parentBean"/> </beans>
可以看到配置文件改为byType。
测试类:
package com.lwf.client; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.lwf.bean.Bean2; public class Client { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext*.xml"); Bean2 bean2 = (Bean2)ctx.getBean("bean2"); System.out.println(bean2.getBean3().getName()); System.out.println(bean2.getBean3().getId()); System.out.println(bean2.getBean4().getId()); System.out.println(bean2.getBean4().getName()); System.out.println(bean2.getBean5().getAge()); } }
注:在这次测试中,Bean3中删除了Date属性,这次因为在测试的时候发现自己写的日期转化类在byType下报错。
本次测试结果:
2010-05-19 17:08:39,732 INFO [org.springframework.context.support.ClassPathXmlApplicationContext] - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@19fcc69: display name [org.springframework.context.support.ClassPathXmlApplicationContext@19fcc69]; startup date [Wed May 19 17:08:39 CST 2010]; root of context hierarchy 2010-05-19 17:08:39,888 INFO [org.springframework.beans.factory.xml.XmlBeanDefinitionReader] - Loading XML bean definitions from file [D:\workdirlocal\spring_autowire\bin\applicationContext.xml] 2010-05-19 17:08:40,201 INFO [org.springframework.context.support.ClassPathXmlApplicationContext] - Bean factory for application context [org.springframework.context.support.ClassPathXmlApplicationContext@19fcc69]: org.springframework.beans.factory.support.DefaultListableBeanFactory@20be79 2010-05-19 17:08:40,263 INFO [org.springframework.beans.factory.support.DefaultListableBeanFactory] - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@20be79: defining beans [bean2,bean5ref,parentBean,bean3ref,bean4ref]; root of factory hierarchy zhang 1 1 zhang 33