Question

我有一个Spring Boot应用程序，我需要有线程绑定的bean。我想要在需要使用Spring的SimpleThreadScope的解决方案。我尝试将其自动装配到@Components，但根据我打印的日志，看起来Spring不会为每个生成的线程创建一个新bean。如何正确地自动接线/配置bean？

这是我的控制人

@RestController
public class Controller {
  @Autowired
  private DummyClass dummyClass;

  @Autowired
  private DummyService1 svc;

  @PostMapping  
  public Result myPostMethod (@RequestBody Request request) {    
    LOGGER.info("myPostMethod " + Thread.currentThread().getName() + " " + Integer.toHexString(this.dummyClass.hashCode()));
    this.svc.doSomething();

    return new Result();
  }
}

我的样本服务

@Service
public class DummyService1 {

  @Autowired
  private DummyClass dummyClass;

  @Autowired
  private DummyService2 service;

  public void doSomething () {
    LOGGER.info("doSomething " + Thread.currentThread().getName() + " " + Integer.toHexString(this.dummyClass.hashCode()));

    this.service.doSomething2();
  }
}

@Service
public class DummyService2 {  

  @Autowired
  private DummyClass dummyClass;

  public void doSomething2 () {
    LOGGER.info("doSomething2 " + Thread.currentThread().getName() + " " + Integer.toHexString(this.dummyClass.hashCode()));
  }
}

我的配置

@Configuration
public class MyConfig implements WebMvcConfigurer {

  @Bean
  @Scope(value = "thread", proxyMode = ScopedProxyMode.TARGET_CLASS)  
  public DummyClass dummyClass () {
    DummyClass ctx = new DummyClass();
    return ctx;
  }

  @Bean
  public static BeanFactoryPostProcessor beanFactoryPostProcessor () {
    return new CustomScopeRegisteringBeanFactoryPostProcessor();
  }
}

public class CustomScopeRegisteringBeanFactoryPostProcessor implements BeanFactoryPostProcessor {
  @Override
  public void postProcessBeanFactory (ConfigurableListableBeanFactory beanFactory) throws BeansException {
    beanFactory.registerScope("thread", new SimpleThreadScope());
  }
}

两次执行后的实际输出

myPostMethod http-nio-8080-exec-4 81823b32
doSomething http-nio-8080-exec-4 81823b32
doSomething2 http-nio-8080-exec-4 81823b32

myPostMethod http-nio-8080-exec-8 81823b32
doSomething http-nio-8080-exec-8 81823b32
doSomething2 http-nio-8080-exec-8 81823b32

两次执行后的预期输出

myPostMethod http-nio-8080-exec-4 81823b32
doSomething http-nio-8080-exec-4 81823b32
doSomething2 http-nio-8080-exec-4 81823b32

myPostMethod http-nio-8080-exec-8 9a5170d
doSomething http-nio-8080-exec-8 9a5170d
doSomething2 http-nio-8080-exec-8 9a5170d

我注意到，如果我在DummyClass中执行一个方法（设置或获取），则将为每个线程创建一个新实例。我的问题是，新创建的对象没有注入到组件中（DummyService1和DummyService2）

Answer 1

WebApplicationContext.SCOPE_REQUEST是Web Aware Scope的一部分，始终为每个请求提供不同的bean

@Scope(value = WebApplicationContext.SCOPE_REQUEST, proxyMode = ScopedProxyMode.TARGET_CLASS)

Spring SimpleThreadScope无法在@Components

1 个答案: