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概述通过Spring管理的类,默认是单例模式,但是如果有的类需要使用独立的属性,则需要配置为多例模式的. 但是多例模式不仅仅只是加一个声明,使用@Autowired进行注入,可能并不会是你想要的结果.因为多例模式的类是需要单独调用的.不搞清楚原理直接测试:需要多例的类上加上注解@Scope(“prototype”)@Component@Scope("prototype")public class ExampleService{ public void test(){ System.out.println("test,current bean is" + this); } }引用直接使用@Autowired@Controllerpublic class ExampleService{ @Autowired private ExampleService exampleService; @RequestMapping("test") public void test(){ exampleService.test(); } }结果: 每个request过来的时候,exampleService实例均为同一个实例.解决办法:第一种:不使用@Autowired@Controllerpublic class ExampleService{ @Autowired private org.springframework.beans.factory.BeanFactory beanFactory; @RequestMapping("test") public void test(){ ExampleService exampleService = beanFactory.getBean(ExampleService.class); exampleService.test(); }}第二种:使用bean工厂@Autowired private ApplicationContext context; @Bean public WebSocketHandler websocketBHandler() { PerConnectionWebSocketHandler perConnectionHandler = new PerConnectionWebSocketHandler(WebSocketBHandler.class); perConnectionHandler.setBeanFactory(context.getAutowireCapableBeanFactory()); //设置bean工厂,否则bean工厂WebSocketBHandler将不会自动连接 return perConnectionHandler; }然后使用ApplicationContext进行代理bean工厂注入@Autowiredprivate ApplicationContext context;使用this.Bservice = context.getBean(BService.class, this);官方文档说明4.5.3 Singleton beans with prototype-bean dependencies When you use singleton-scoped beans with dependencies on prototype beans, be aware that dependencies are resolved at instantiation time. Thus if you dependency-inject a prototype-scoped bean into a singleton-scoped bean, a new prototype bean is instantiated and then dependency-injected into the singleton bean. The prototype instance is the sole instance that is ever supplied to the singleton-scoped bean. However, suppose you want the singleton-scoped bean to acquire a new instance of the prototype-scoped bean repeatedly at runtime. You cannot dependency-inject a prototype-scoped bean into your singleton bean, because that injection occurs only once, when the Spring container is instantiating the singleton bean and resolving and injecting its dependencies. If you need a new instance of a prototype bean at runtime more than once, see Section 4.4.6, “Method injection”
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