Bean 的六种作用域

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Bean的作用域
属性注入和content获取Bean
- 单例作用域:http://127.0.0.1:8080/single1
- [多例作用域: http://127.0.0.1:8080/prototype](#多例作用域: http://127.0.0.1:8080/prototype)
- [请求作用域: http://127.0.0.1:8080/request](#请求作用域: http://127.0.0.1:8080/request)
- [会话作用域: http://127.0.0.1:8080/session](#会话作用域: http://127.0.0.1:8080/session)
- [Application作用域: http://127.0.0.1:8080/application](#Application作用域: http://127.0.0.1:8080/application)

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Bean的作用域

作用域	说明
singleton	单例作用域, 每个Spring IoC容器内同名称的bean只有⼀个实例(单例)(默认)
prototype	原型作用域,每次使用该bean时会创建新的实例(非单例)
request	请求作用域 ,每个HTTP 请求生命周期内, 创建新的实例(web环境中)
session	会话作用域 ,每个HTTP Session生命周期内, 创建新的实例(web环境中)
application	全局作用域,每个ServletContext生命周期内, 创建新的实例(web环境中)
websocket	HTTP WebSocket 作用域 ,每个WebSocket生命周期内, 创建新的实例(web环境中)

java 复制代码

package com.example.demo.config;

import com.example.demo.model.User;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;
import org.springframework.web.context.annotation.ApplicationScope;
import org.springframework.web.context.annotation.RequestScope;
import org.springframework.web.context.annotation.SessionScope;

@Configuration
public class BeanConfig {
    @Bean
    @Scope(ConfigurableBeanFactory.SCOPE_SINGLETON)
    public User single1(){
        return new User();
    }
    @Bean
    public User single2(){
        return new User();
    }
    @Bean
    @Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
    public User prototype(){
        return new User();
    }
    @Bean
    @RequestScope
    public User request(){
        return new User();
    }
    @Bean
    @SessionScope
    public User session(){
        return new User();
    }
    @Bean
    @ApplicationScope
    public User application(){
        return new User();
    }
}

java 复制代码

package com.example.demo.controller;

import com.example.demo.model.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {
    @Autowired
    private User single1;
    @Autowired
    private User single2;
    @Autowired
    private User prototype;
    @Autowired
    private User request;
    @Autowired
    private User session;
    @Autowired
    private User application;

    @Autowired
    ApplicationContext applicationContext;
    @RequestMapping("/single1")
    public String single1(){
        User user = (User) applicationContext.getBean("single1");
        return user.toString()+single1.toString();
    }
    @RequestMapping("/single2")
    public String single2(){
        User user = (User) applicationContext.getBean("single2");
        return user.toString()+single2.toString();
    }
    @RequestMapping("/prototype")
    public String prototype(){
        User user = (User) applicationContext.getBean("prototype");
        return user.toString()+prototype.toString();
    }@RequestMapping("/request")
    public String request(){
        User user = (User) applicationContext.getBean("request");
        return user.toString()+request.toString();
    }@RequestMapping("/session")
    public String session(){
        User user = (User) applicationContext.getBean("session");
        return user.toString()+session.toString();
    }@RequestMapping("/application")
    public String application(){
        User user = (User) applicationContext.getBean("application");
        return user.toString()+application.toString();
    }
}