Bean作用域

今天研究了一下scope的作用域。默认是单例模式，即scope="singleton"。另外scope还有prototype、request、session、global session作用域。scope="prototype"多例。再配置bean的作用域时，它的头文件形式如下：

如何使用spring的作用域：

<bean id="role" class="spring.chapter2.maryGame.Role" scope="singleton"/>

这里的 scope 就是用来配置 spring bean 的作用域，它标识 bean 的作用域。

1、

package com.longteng.lesson2.dao;

public interface IOrderDao {
    public String bookOrder(String name);
}

2、

package com.longteng.lesson2.dao.impl;

import com.longteng.lesson2.dao.IOrderDao;
import org.springframework.stereotype.Repository;

@Repository
public class OrderDao implements IOrderDao {
    @Override
    public String bookOrder(String name) {
        return name+"预订了订单";
    }
}

3、 

package com.longteng.lesson2.service;
import com.longteng.lesson2.dao.IOrderDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

@Service
@Scope("prototype")
public class OrderService {


    IOrderDao iOrderDao;
    @Autowired
    public void setiOrderDao(IOrderDao iOrderDao) {
        this.iOrderDao = iOrderDao;
    }

    public String  getOrderInfo(String name){
       return iOrderDao.bookOrder(name);
    }
    @PostConstruct
    public void initTest(){
        System.out.println("初始化调用方法");
    }
    @PreDestroy
    public void tearDownTest(){
        System.out.println("回收调用方法");
    }
}

4、

package com.longteng.lesson2.config;

import com.longteng.lesson2.service.OrderService;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan(basePackages = {"com.longteng.lesson2.dao","com.longteng.lesson2.service"})
public class OrderCfg {

    @Bean
    public OrderService getOrderService(){
        return new OrderService();
    }
}

5、  

package com.longteng.lesson2.dao;

import com.longteng.lesson2.config.OrderCfg;
import com.longteng.lesson2.service.OrderService;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class OrderDaoTest {
    ApplicationContext context;
    @Before
    public void initApplication(){
        context = new AnnotationConfigApplicationContext(OrderCfg.class);
    }
    @Test
    public void test(){
        OrderService orderService = context.getBean("orderService", OrderService.class);
        OrderService orderService1 = context.getBean("orderService", OrderService.class);
        System.out.println(orderService==orderService1);
    }
}

6、

15:01:44.959 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Invoking init method on bean 'orderService': public void com.longteng.lesson2.service.OrderService.initTest()
初始化调用方法
15:01:44.959 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'orderService'
false

Process finished with exit code 0

 ---------------------------------------------方法2通过在xml 里面配置scope关键字

1、

package com.longteng.lesson2.dao;

public interface IOrderDao {
    public String bookOrder(String name);
}

2、

package com.longteng.lesson2.dao.impl;

import com.longteng.lesson2.dao.IOrderDao;
import org.springframework.stereotype.Repository;

public class OrderDao implements IOrderDao {
    @Override
    public String bookOrder(String name) {
        return name+"预订了订单";
    }
}

 3、

package com.longteng.lesson2.service;
import com.longteng.lesson2.dao.IOrderDao;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

public class OrderService {

    IOrderDao iOrderDao;
    public void setiOrderDao(IOrderDao iOrderDao) {
        this.iOrderDao = iOrderDao;
    }

    public String  getOrderInfo(String name){
       return iOrderDao.bookOrder(name);
    }
    @PostConstruct
    public void initTest(){
        System.out.println("初始化调用方法");
    }
    @PreDestroy
    public void tearDownTest(){
        System.out.println("回收调用方法");
    }
}

4、

<?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: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">
    <context:component-scan base-package="com.longteng.lesson2.dao.impl,com.longteng.lesson2.service"/>
    <bean id="orderDao" class="com.longteng.lesson2.dao.impl.OrderDao"></bean>
    <bean id="orderService" class="com.longteng.lesson2.service.OrderService" scope="prototype">
        <property name="iOrderDao" ref="orderDao"></property>
    </bean>
</beans>

5、

15:05:47.201 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Invoking init method on bean 'orderService': public void com.longteng.lesson2.service.OrderService.initTest()
初始化调用方法
15:05:47.201 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'orderService'
15:05:47.201 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating instance of bean 'orderService'
15:05:47.201 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'orderDao'
15:05:47.202 [main] DEBUG org.springframework.context.annotation.CommonAnnotationBeanPostProcessor - Invoking init method on bean 'orderService': public void com.longteng.lesson2.service.OrderService.initTest()
初始化调用方法
15:05:47.202 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'orderService'
false

Process finished with exit code 0