項目里面有比較多的導入導出，錄音文件加載等功能，但是有個問題是：導入導出客戶端可能會頻繁的點擊，錄音文件一次性可能會加載多個。如果導出的excel文件過大，或者加載的錄音文件過多，或者一個音頻文件過長，可能會出現 這個異常：
org.apache.catalina.connector.ClientAbortException: java.io.IOException: APR error: -32 at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:396) at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:344) at org.apache.catalina.connector.OutputBuffer.writeBytes(OutputBuffer.java:421) at org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:409) at org.apache.catalina.connector.CoyoteOutputStream.write(CoyoteOutputStream.java:97) at java.io.BufferedOutputStream.write(BufferedOutputStream.java:122) at java.io.FilterOutputStream.write(FilterOutputStream.java:97) at com.zhuanche.serv.punish.DriverPunishClientService.renderVideo(DriverPunishClientService.java:181) at com.zhuanche.controller.driver.DriverPunishController.render(DriverPunishController.java:138) at com.zhuanche.controller.driver.DriverPunishController$$FastClassBySpringCGLIB$$1182fa42.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) at org.apache.shiro.spring.security.interceptor.AopAllianceAnnotationsAuthorizingMethodInterceptor$1.proceed(AopAllianceAnnotationsAuthorizingMethodInterceptor.java:82) at org.apache.shiro.authz.aop.AuthorizingMethodInterceptor.invoke(AuthorizingMethodInterceptor.java:39) at org.apache.shiro.spring.security.interceptor.AopAllianceAnnotationsAuthorizingMethodInterceptor.invoke(AopAllianceAnnotationsAuthorizingMethodInterceptor.java:115) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673) at com.zhuanche.controller.driver.DriverPunishController$$EnhancerBySpringCGLIB$$fbb8c231.render(<generated>) at sun.reflect.GeneratedMethodAccessor2068.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
這個問題困擾了好久，解決方法有限制過前端的頻繁點擊的按鈕，比如沒分鍾只允許點擊一次，后端有加緩存的限制，比如以用戶id+請求條件+請求ip作為key，防止頻繁的請求。如果請求頻繁，則導出一個空Excel文件以及提示語。但是由於太多地方，仍然會時不時的拋出這個 arp -32的問題。今天想到用異步線程池的方式，參考：
https://blog.csdn.net/Muscleheng/article/details/81409672 。
我是采用的注解+@Async方式，但是發現仍然不管用。特別是加載錄音文件，還拋出了空指針異常。自己的代碼：Controller
@RequiresPermissions(value = {"punishTripVideo"})
@RequestMapping("/renderVideo")
@ResponseBody
public AjaxResponse render(@RequestParam(name = "filePath") String filePath, HttpServletResponse response) {
if (StringUtils.isBlank(filePath)) {
return AjaxResponse.failMsg(RestErrorCode.HTTP_FORBIDDEN, "缺失路徑");
}
log.info("渲染錄音文件, filePath:{}", filePath);
try {
driverPunishService.renderVideo(filePath, response);
} catch (Exception e) {
log.error("渲染失敗",e);
return AjaxResponse.failMsg(RestErrorCode.HTTP_FORBIDDEN, "渲染失敗");
}
return AjaxResponse.success(null);
}
service:
/** * 渲染行程錄音 * @param filePath * @param response * @throws IOException */ public void renderVideo(String filePath,HttpServletResponse response) throws IOException { log.info("====threadName==== 異步線程池執行該service方法==="); OutputStream outputStream = null; try { byte[] fileBytes = OkHttpStreamUtil.executeForBytes(filePath); if (Objects.nonNull(fileBytes)) { //支持范圍請求 int fileLength = fileBytes.length; response.addHeader("Accept-Ranges", "bytes"); response.addHeader("Content-Length", "" + fileLength); response.addHeader("Content-Range", "bytes 0-" + fileLength); response.addHeader("Content-Type", "audio/mpeg"); response.addHeader("Content-Length", "" + fileLength); outputStream = new BufferedOutputStream(response.getOutputStream()); outputStream.write(fileBytes); outputStream.flush(); } } catch (IOException io) { log.warn("渲染行程錄音IOException", io); } catch (Exception e) { log.error("渲染行程錄音失敗", e); throw e; } finally { IoUtil.close(outputStream); } }
使用異步線程池類：
package com.zhuanche.serv.sync; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.scheduling.annotation.EnableAsync; import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor; import java.util.concurrent.ThreadPoolExecutor; /** * @author fanht * @description 異步線程池 * @date 2021/1/5 上午9:48 * @version 1.0 */ @Configuration @EnableAsync public class SyncThreadPool { /**核心線程數*/ private static final Integer CORE_POOL_SIZE = 20; /**最大線程數*/ private static final Integer MAX_POOL_SIZE = 100; /**允許線程空閑時間 （單位 秒）*/ private static final Integer KEEP_ALIVE_TIME = 10; /**緩沖隊列大小*/ private static final Integer QUEUE_CAPACITY = 200; /**線程名前綴 主要是在service層使用*/ private static final String THREADNAME_PREFIX = "Async-service-"; @Bean("syncTaskExecutor") public ThreadPoolTaskExecutor syncTaskExecutor(){ ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor(); taskExecutor.setCorePoolSize(CORE_POOL_SIZE); taskExecutor.setMaxPoolSize(MAX_POOL_SIZE); taskExecutor.setKeepAliveSeconds(KEEP_ALIVE_TIME); taskExecutor.setQueueCapacity(QUEUE_CAPACITY); taskExecutor.setThreadNamePrefix(THREADNAME_PREFIX); // 線程池對拒絕任務的處理策略 // CallerRunsPolicy：由調用線程（提交任務的線程）處理該任務 taskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy()); taskExecutor.initialize(); return taskExecutor; } }
然后在service的方法前面加上@Async("syncTaskExecutor"),發現還是不行。而且拋異常了，問題是由於使用了異步線程池后，controller的線程是 tomcat提供的，而server的是使用的異步線程池。傳的outputStream 為空了（詳見： https://cloud.tencent.com/developer/article/1511820）
不過這也給自己了提示：既然是tomcat超時了，那是不是可以通過調整tomcat的超時時間來延長呢？ 我們知道 tomcat的 server.xml的 默認配置是如下：
<Connector port="8080" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" />
會不會是這個默認的超時時間太短了呢？我把時間改成60000試下。