spring框架学习四(ioc如何创建对象)
IOC
1.无参构造创建对象,
2.实体类
package com.yms.entity;
/**
- @Author 杨明书
- @PackageName: com.yms.entity
- @ClassName: User
- @Description:
- @Date: 2021/12/29 14:11
*/
public class User {
private String name;
// public User(){
// System.out.println("user 的无参构造");
// }
public User(String name){
this.name=name;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public void show(){
System.out.println("姓名为:"+name);
}
}
3.配置文件
<bean id="user" class="com.yms.entity.User">
<!-- 无参赋值-->
<constructor-arg name="name" value="钟无艳"></constructor-arg>
</bean>
4.测试类
import com.yms.entity.User;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
- @Author 杨明书
- @PackageName: PACKAGE_NAME
- @ClassName: MyTest
- @Description:
- @Date: 2021/12/29 14:13
*/
public class MyTest {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
User user = (User) context.getBean("user");
user.show();
// User user = new User();
}
}