3. Spring4.x Bean的Scope

Bean的Scope的简单示例

通过@Scope指定以下参数值

Singleton       单例的 (默认配置)
Prototype       多例的
Request         web项目中request级别的单例
Session         web项目中session级别的单例

GlobalSession   portal应用(不知道是啥...)

1. 新建一个Scope为Singleton的类

package com.xiaohan.scope;

import org.springframework.stereotype.Service;

@Service
// 可省略
// @Scope("singleton")
public class SingletonService {
}

2. 新建一个Scope为Prototype的类

package com.xiaohan.scope;

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

@Service
@Scope("prototype")
public class PrototypeService {
}

3. 配置类

package com.xiaohan.scope;

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

@Configuration
@ComponentScan("com.xiaohan.scope")
public class ScopeConfig {
}

4. Main测试

package com.xiaohan.scope;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

// Bean的Scope
public class Main {
    public static void main(String[] args) {
        ApplicationContext ac = new AnnotationConfigApplicationContext(ScopeConfig.class);
        SingletonService s1 = ac.getBean(SingletonService.class);
        SingletonService s2 = ac.getBean(SingletonService.class);
        System.err.println(s1.equals(s2));  //true

        PrototypeService p1 = ac.getBean(PrototypeService.class);
        PrototypeService p2 = ac.getBean(PrototypeService.class);
        System.err.println(p1.equals(p2));  //false
    }
}