IOC创建对象的几种方式

    public User(){
        super();
        System.out.println("无参数构造器");
    }
    
    public User(int id, String name){
        System.out.println("带参数构造器");
        this.id = id;
        this.name = name;
    }    

<bean id="user" class="com.isoftstone.bean.User"></bean> <!--无参数-->

    @Test
    public void testIOC(){
        //创建容器对象
        ApplicationContext ac = new ClassPathXmlApplicationContext("com/isoftstone/xml/applicationContext.xml");
        //获取容器中的对象
        User user = (User)ac.getBean("user");
        
    }
//输出"无参数构造器"

<!-- 调用带参数构造器  --> <!--方法1-->
    <bean id="user" class="com.isoftstone.bean.User">
        <constructor-arg value="100" index="0" type="int" ></constructor-arg>
        <constructor-arg value="StanLong" index="1" type="java.lang.String"></constructor-arg>
    </bean> 


<!--方法二 依赖参数-->
<bean id="str" class="java.lang.String">
    <constructor-arg value="StanLong"></constructor-arg>    
</bean>
<bean id="user" class="com.isoftstone.bean.User">
   <constructor-arg index="0" type="int" value="100"  ></constructor-arg>
   <constructor-arg index="1" type="java.lang.String" ref="str"></constructor-arg>
 </bean> 

    @Test
    public void testIOC(){
        //创建容器对象
        ApplicationContext ac = new ClassPathXmlApplicationContext("com/isoftstone/xml/applicationContext.xml");
        //获取容器中的对象
        User user = (User)ac.getBean("user");
        
        System.out.println(user.getId());
        System.out.println(user.getName());
        
    }

//输出"带参数构造器    100     StanLong"

//先创建一个工厂类
//工厂类
public class ObjectFactory {
    
    //实例方法创建对象
    public User getInstance(){
        return new User(100, "调用实例方法");
    }
    
    //静态方法创建对象
    public static User getStaticInstance(){
        return new User(101, "调用静态方法");
    }

}

<!-- 工厂类创建对象 -->
    <!-- #实例方法 -->
    <!-- 先创建工厂 -->
    <bean id="factory" class="com.isoftstone.factory.ObjectFactory">
    </bean>
   <!-- 再创建User对象、用factory实例方法 -->
    <bean id="user" factory-bean="factory" factory-method="getInstance">
    </bean>

  @Test
    public void testIOC(){
        //创建容器对象
        ApplicationContext ac = new ClassPathXmlApplicationContext("com/isoftstone/xml/applicationContext.xml");
        //获取容器中的对象
        User user = (User)ac.getBean("user");
        
        System.out.println(user.getId());
        System.out.println(user.getName());
        
    }

//输出"带参数构造器    100  调用实例方法"

<!-- #工厂类的静态方法 -->
    <bean id="user" class="com.isoftstone.factory.ObjectFactory" factory-method="getStaticInstance">
    </bean>

  @Test
    public void testIOC(){
        //创建容器对象
        ApplicationContext ac = new ClassPathXmlApplicationContext("com/isoftstone/xml/applicationContext.xml");
        //获取容器中的对象
        User user = (User)ac.getBean("user");
        
        System.out.println(user.getId());
        System.out.println(user.getName());
        
    }

//输出"带参数构造器    101  调用静态方法"