Spring Boot中Amazon SQS监听器调用REST接口报错求解决方案

我在Spring Boot应用中配置了Amazon SQS监听器，接收队列消息后需要调用REST API，但调用时出现如下错误：

java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
   at org.springframework.web.context.request.RequestContextHolder.currentRequestAttributes(RequestContextHolder.java:131)

排查后发现，第三方库中的REST Template会尝试从RequestContextHolder读取属性，但SQS监听器的执行线程不在Web请求上下文内，导致报错，且无法修改该REST Template。请问这种情况该如何处理？

由于SQS监听器属于异步非Web请求场景，而第三方REST Template依赖Web请求上下文，可通过手动模拟请求上下文的方式规避问题，具体方案如下：

方案1：手动创建并绑定空请求上下文 #

在调用第三方REST API前后，手动为当前线程绑定空的请求上下文，调用完成后清理，避免线程污染。示例代码：

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.mock.web.MockHttpServletRequest;
import org.springframework.mock.web.MockHttpServletResponse;

// SQS监听器的消息处理方法
public void handleSqsMessage(String message) {
    // 创建模拟的请求响应对象
    ServletRequestAttributes emptyAttributes = new ServletRequestAttributes(
            new MockHttpServletRequest(), new MockHttpServletResponse());
    
    // 绑定上下文到当前线程
    RequestContextHolder.setRequestAttributes(emptyAttributes);
    
    try {
        // 调用第三方REST Template的API
        thirdPartyRestClient.callApi();
    } finally {
        // 清理上下文，防止线程池线程携带旧上下文
        RequestContextHolder.resetRequestAttributes();
    }
}

注意：如果第三方库需要特定请求属性，可在MockHttpServletRequest中预先设置对应值。

方案2：通过自定义线程池统一初始化上下文 #

如果使用自定义线程池处理SQS消息，可通过TaskDecorator为每个线程初始化空请求上下文，无需在每个消息处理方法中重复编写代码：

1. 配置带任务装饰器的自定义线程池：

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.mock.web.MockHttpServletRequest;
import org.springframework.mock.web.MockHttpServletResponse;

@Configuration
public class ThreadPoolConfig {
    @Bean
    public ThreadPoolTaskExecutor sqsTaskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(5);
        executor.setMaxPoolSize(10);
        executor.setQueueCapacity(20);
        executor.setThreadNamePrefix("sqs-listener-");
        
        // 任务装饰器：为每个线程初始化空请求上下文
        executor.setTaskDecorator(runnable -> () -> {
            ServletRequestAttributes emptyAttributes = new ServletRequestAttributes(
                    new MockHttpServletRequest(), new MockHttpServletResponse());
            RequestContextHolder.setRequestAttributes(emptyAttributes);
            try {
                runnable.run();
            } finally {
                RequestContextHolder.resetRequestAttributes();
            }
        });
        
        executor.initialize();
        return executor;
    }
}

2. 在SQS监听器配置中指定使用该线程池：

import org.springframework.cloud.aws.messaging.listener.SimpleMessageListenerContainer;
import org.springframework.cloud.aws.messaging.listener.SqsMessageDeletionPolicy;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.amazonaws.services.sqs.AmazonSQSAsync;

@Configuration
public class SqsConfig {
    @Bean
    public SimpleMessageListenerContainer simpleMessageListenerContainer(
            AmazonSQSAsync amazonSQSAsync, ThreadPoolTaskExecutor sqsTaskExecutor) {
        SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
        container.setAmazonSqs(amazonSQSAsync);
        container.setQueueNames("your-queue-name");
        container.setMessageDeletionPolicy(SqsMessageDeletionPolicy.ON_SUCCESS);
        // 指定自定义线程池
        container.setTaskExecutor(sqsTaskExecutor);
        return container;
    }
}

内容的提问来源于stack exchange，提问作者Do Will