一、spring的开发步骤

package com.lt.dao;

public interface UserDao {
    void  save();
}

package com.lt.dao.impl;

import com.lt.dao.UserDao;

public class UserDaoImpl implements UserDao {
    public void save() {
        System.out.println("save runing");

    }
}

1、导入坐标 pom.xml

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
    </dependencies>

2、创建spring config文件(resources文件夹下)，添加bean

<bean id="userDao" class="com.lt.dao.impl.UserDaoImpl"/>

3、调用

import com.lt.dao.UserDao;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class UserDaoDemo {
    public static void main(String[] args) {
        ApplicationContext app =new ClassPathXmlApplicationContext("applicationContext.xml");
        UserDao userDao = (UserDao) app.getBean("userDao");
        userDao.save();


    }
}

二、bean中的scope，init-method，destroy-method

1、实现

package com.lt.dao.impl;

import com.lt.dao.UserDao;

public class UserDaoImpl implements UserDao {

    public UserDaoImpl() {
        System.out.println("UserDaoImpl创建");
    }
    public void save() {
        System.out.println("save runing");

    }


    //方法名随便起
    public  void init(){
        System.out.println("UserDaoImpl初始化");
    }
    public  void destroy(){
        System.out.println("UserDaoImpl 销毁");
    }

}

2、配置

<!--   方法一：无参构造方法实例化-->
   <!--id=bean实例在spring容器里的唯一标识，
   class=bean的全限定名,
   scope=作用范围。默认单例singleton（加载配置文件时创建） 或多例 prototype（getBean()方法时创建）
   init-method=初始化方法。
   destroy-method=销毁方法
   -->
   <bean id="userDao" class="com.lt.dao.impl.UserDaoImpl" scope="singleton"
   init-method="init" destroy-method="destroy"
   />

三、工厂静态方法实例化

package com.lt.factory;

import com.lt.dao.UserDao;
import com.lt.dao.impl.UserDaoImpl;

public class StaticFactory {
    public static UserDao getUserDao(){
        return  new UserDaoImpl();
    }
}

<!--   方法二：工厂静态方法实例化-->
      <bean id="userDao"  class="com.lt.factory.StaticFactory"
            factory-method="getUserDao"/>

四、工厂动态方法实例化

package com.lt.factory;

import com.lt.dao.UserDao;
import com.lt.dao.impl.UserDaoImpl;

public class DynamicFactory {
    public UserDao getUserDao(){
        return  new UserDaoImpl();
    }
}

<!--   方法三：工厂动态方法实例化-->
       <bean id="factory" class="com.lt.factory.DynamicFactory"/>
       <bean id="userDao" factory-bean="factory" factory-method="getUserDao"/>

 

本文地址：https://blog.csdn.net/tiz198183/article/details/112291218