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:context="http://www.springframework.org/schema/context"
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/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"
default-lazy-init="false">
<!-- default-lazy-init用于指定所有的单例对象默认初始化的时机,默认为false -->
<!-- scope属性用于指定bean的生命周期,
singleton表示单例,每次ac.getBean()返回的都是同一个对象,
prototype表示原型/多例,每次ac.getBean()都会生成新的对象,
默认为单例 -->
<!-- lazy-init属性表示什么时候开始创建单例对象,只对单例有效,
true表示在需要创建对象的时候才开始创建,
false表示在容器启动的时候就开始创建对象,
默认与default-lazy-init的值一样 -->
<bean id="user1" class="com.colorlight.springscope.User" scope="singleton"
lazy-init="true">
<property name="id" value="1"></property>
<property name="name" value="lijun"></property>
<property name="password" value="199192"></property>
</bean>
<bean id="user2" class="com.colorlight.springscope.User" scope="prototype">
<property name="id" value="1"></property>
<property name="name" value="lijun"></property>
<property name="password" value="199192"></property>
</bean>
</beans>
User类:
package com.colorlight.springscope;
public class User {
private int id;
private String name;
private String password;
public User(){
System.out.println("创建了User的实例!");
}
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;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
测试类:
package com.colorlight.springscope;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainTest {
ApplicationContext ac = new ClassPathXmlApplicationContext(
"applicationContext.xml", this.getClass());
// 单例
@Test
public void test1() {
System.out.println("在getBean()调用之前");
User user1 = (User) ac.getBean("user1");
User user2 = (User) ac.getBean("user1");
System.out.println(user1 != null);
System.out.println(user1 == user2);
}
// 多例
@Test
public void test2() {
System.out.println("在getBean()调用之前");
User user1 = (User) ac.getBean("user2");
User user2 = (User) ac.getBean("user2");
System.out.println(user1 != null);
System.out.println(user1 == user2);
}
}