我对@async和rest模板调用有问题；这是我的主要应用程序类，带有一个任务执行器bean和enablesync注解
@SpringBootApplication
@ComponentScan({"org.***"})
@EnableAspectJAutoProxy
@EnableAsync
@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class,HibernateJpaAutoConfiguration.class})
@EnableFeignClients(basePackages = {"org.service.feign"})
public class MainApplication extends SpringBootServletInitializer {
/**
* <p>main.</p>
*
* @param args an array of {@link java.lang.String} objects.
*/
public static void main(String[] args) {
SpringApplication.run(MainApplication.class, args);
}
@Bean(name = "threadPoolTaskExecutor")
public Executor taskExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(5);
executor.setMaxPoolSize(5);
executor.setQueueCapacity(100);
executor.setThreadNamePrefix(“CustomLookup-");
executor.initialize();
return executor;
}
/**
* Configure.
*
* @param application the application
* @return the spring application builder
*/
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(MainApplication.class);
}
/**
* <p>requestContextListener.</p>
*
* @return a {@link org.springframework.web.context.request.RequestContextListener} object.
*/
@Bean
public RequestContextListener requestContextListener() {
return new RequestContextListener();
}
}这是我在rest控制器中调用的带有异步注解的测试服务：
@Service
public class TestService {
@Async("threadPoolTaskExecutor")
public ResponseEntity<Object> test()
throws Exception{
PagedRequest<SearchRequest> request = new PagedRequest<SearchRequest>();
SearchRequest filters = new Request();
filters.setCod(“abcdeg");
request.setFilters(filters);
RestTemplate restTemplate = new RestTemplate();
restTemplate.setInterceptors(Collections.singletonList(new RestInterceptor())); // here I set a custom headers
final HttpHeaders theJsonHeader = new HttpHeaders();
theJsonHeader.setContentType(MediaType.APPLICATION_JSON);
final MultiValueMap<String, Object> theMultipartRequest = new LinkedMultiValueMap<>();
ObjectMapper objectMapper = new ObjectMapper();
String someJsonString = objectMapper.writeValueAsString(request);
theMultipartRequest.add("request", new HttpEntity<>(someJsonString, theJsonHeader));
ResponseEntity<Object> response = null;
final HttpEntity<PagedRequest<SearchRequest>> theHttpEntity = new HttpEntity<>(request, theJsonHeader);
String path = “http://...”; //url removed for privacy
response = restTemplate.postForEntity(path, theHttpEntity, Object.class);
return response;
}
}此服务返回rest模板上的空指针；这是stacktrace
java.lang.NullPointerException: null
at org.springframework.web.client.DefaultResponseErrorHandler.hasError(DefaultResponseErrorHandler.java:61) ~[spring-web-5.2.3.RELEASE.jar:5.2.3.RELEASE]
at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:773) ~[spring-web-5.2.3.RELEASE.jar:5.2.3.RELEASE]
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:743) ~[spring-web-5.2.3.RELEASE.jar:5.2.3.RELEASE]
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:677) ~[spring-web-5.2.3.RELEASE.jar:5.2.3.RELEASE]
at org.springframework.web.client.RestTemplate.postForEntity(RestTemplate.java:452) ~[spring-web-5.2.3.RELEASE.jar:5.2.3.REL这里是我在resttemplate中添加的restintercept代码
public class RestInterceptor implements ClientHttpRequestInterceptor {
@Override
public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
if (requestAttributes == null)
return null;
HttpServletRequest req = requestAttributes.getRequest();
if (req == null || req.getHeader(PrevConstants.USER_KEY)==null || req.getHeader(PrevConstants.JWT_HEADER_NAME)==null)
return null;
String userKey = req.getHeader(PrevConstants.USER_KEY);
String jwt = req.getHeader(PrevConstants.JWT_HEADER_NAME);
if (jwt == null) {
jwt = "custom jwt";
}
else if ( !jwt.startsWith("Bearer")) { jwt = "Bearer " + jwt; }
request.getHeaders().set(PrevConstants.USER_KEY, userKey);
request.getHeaders().set(PrevConstants.JWT_HEADER_NAME, jwt);
ClientHttpResponse response = execution.execute(request, body);
return response;
}
}但是如果我删除，@enablesync和@async，那么简单的rest模板就可以完美地工作。有什么问题吗？我不知道。谢谢你的回复
2条答案
按热度按时间fnx2tebb1#
RequestContextHolder保存当前线程正在处理的请求的上下文。当你使用@Async您的拦截器在处理请求的线程的不同线程上被调用。因此，RequestContextHolder.getRequestAttributes()返回null然后你的拦截器返回一个null答复。遵守合同ClientHttpRequestInterceptor#intercept它必须返回一个非空值，因此null响应导致失败。如果你想用
@Async，您必须检索RequestAttributes在rest控制器中，然后将它们传递到TestService作为test方法。然后，您可以创建RestInterceptor使用属性，而不是使用RequestContextHolder要访问它们：rt4zxlrg2#
@andy，我已经直接从我的rest控制器传递了第一个requestattributes和第二个片刻的httpservletrequest，但结果是相同的，nullpointer。你有我能看到的剪报吗？
和