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)));
    }
}