user.java

package com.pactera.springBean;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Component;

@Component("user"
 
)//物件user加入IOC容器，id為user
@Lazy(true)//一旦指定懶載入，註解value預設時true
public class User {

    public User(){
        System.out.println("建立 user ");
    }

    private String name="liuqi";
    private int age=18;

    @Autowired              //根據型別去容器中查詢，如果容器中有多個同類型的物件，會丟擲異常 。@Resource有兩個屬性name ,type
                            //1指定name和type會根據名稱和型別去找唯一的物件2.指定name會去根據id查詢3.指定type會根據型別查詢
 

                            //4.都不指定會先根據名稱查詢，沒找到再根據型別查詢，當有多個同類型時會丟擲異常
    private String address;

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

    @PostConstruct      //初始化方法
    public void initUser(){
        System.out.println("init user");
    }

    @PreDestroy     //銷燬容器物件的時候自動呼叫
 

    public void destoryUser(){
        System.out.println("destory user");
    }

    @Override
    public String toString() {
        return "User [name=" + name + ", age=" + age + ", address=" + address
                + "]";
    }
}

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"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation=
    "http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context.xsd">
    <bean id="address" class="java.lang.String">
        <constructor-arg value="上海"></constructor-arg>
    </bean>

    <!-- <bean id="address2" class="java.lang.String">
        <constructor-arg value="上海"></constructor-arg>
    </bean> -->


    <!-- 掃描包，將配有指定註解的類注入容器 -->
    <context:component-scan base-package="com.pactera"></context:component-scan>

</beans>   

測試

package com.pactera.springBeanTest;

import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.pactera.springBean.User;

public class TestSpringBean {

    @Test
    public void testIOC(){
        ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
        User user = ac.getBean("user", User.class);
        System.out.println(user);
        ac.destroy();
    }
}