Bean的Scope

Bean的scope:

1、Singleton(单例)： 一个Spring容器只有以这个Bean实例。

2、prototype(多例)： 每次调用新建一个Bean的实例。

3、request：一个http request请求一个Bean实例。

4、Session：一个http session请求一个Bean实例。

5、GlobalSession：portal应用中有用

 package com.wisely.heighlight_spring4.ch2.scope;

 import org.springframework.context.annotation.Scope;
 import org.springframework.stereotype.Service;

 @Service
 @Scope("singleton")        //配置作用域单列(默认就是单列)
 public class DemoSingletonService {

 }

 package com.wisely.heighlight_spring4.ch2.scope;

 import org.springframework.context.annotation.Scope;
 import org.springframework.stereotype.Service;

 @Service
 @Scope("prototype")            //配置作用域是多列
 public class DemoPrototypeService {

 }

 package com.wisely.heighlight_spring4.ch2.scope;

 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;

 @Configuration
 @ComponentScan("com.wisely.heighlight_spring4.ch2.scope")
 public class ScopeConfig {

 }

package com.wisely.heighlight_spring4.ch2.scope;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class Main {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ScopeConfig.class);
        DemoSingletonService demoSingletonService1 = context.getBean(DemoSingletonService.class);
        DemoSingletonService demoSingletonService2 = context.getBean(DemoSingletonService.class);
        System.out.println("Singleton++++"+(demoSingletonService1.equals(demoSingletonService2)));

        DemoPrototypeService demoPrototypeService1 = context.getBean(DemoPrototypeService.class);
        DemoPrototypeService demoPrototypeService2 = context.getBean(DemoPrototypeService.class);
        System.out.println("prototype++++"+(demoPrototypeService1.equals(demoPrototypeService2)));
    }
}