(1)空参构造,(2)静态工厂(3)实例工厂
------测试代码
package cn.itcast.b_create;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import cn.itcast.bean.User;
//测试spring创建对象的方式
public class Demo {
@Test
public void fun1() {
// 1、空参构造
ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
User user = (User) ac.getBean("user");
}
@Test
public void fun2() {
// 1、静态工厂构造,即我们不需要spring帮我们创建对象,我们自己创建好了,只希望spring进行管理
ApplicationContext ac = new ClassPathXmlApplicationContext("cn/itcast/b_create/applicationContext.xml");
User user = (User) ac.getBean("user2");
}
@Test
public void fun3() {
// 1、实例工厂构造
ApplicationContext ac = new ClassPathXmlApplicationContext("cn/itcast/b_create/applicationContext.xml");
User user = (User) ac.getBean("user3");
}
}
------工厂类
package cn.itcast.b_create;
import cn.itcast.bean.User;
public class UserFactory {
public static User createUser() {
System.out.println("静态工厂构造");
return new User();
}
public User createUser3() {
System.out.println("实例工厂构造");
return new User();
}
}
(3)配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/beans"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd ">
<!-- 空参构造 -->
<bean name="user" class="cn.itcast.bean.User"></bean>
<!-- 静态工厂构造 -->
<bean name="user2" class="cn.itcast.b_create.UserFactory"
factory-method="createUser"></bean>
<!-- 实例工厂构造 -->
<!-- 其与静态工厂不同之处在于,,,静态工厂处的方法为静态方法,其直接类.方法即可,而对于实例工厂来说,则需要new出新的对象在访问 所以需要先生成该类 -->
<bean name="user3" factory-bean="createUser3" factory-method="createUser3"></bean>
<bean name="createUser3" class="cn.itcast.b_create.UserFactory"></bean>
</beans>