Springboot定时任务卡死问题

springboot框架使用@Scheduled注解实现的单线程定时任务卡死，原因一般是没有设置超时策略导致无限期等待。

定位问题代码

1. 使用jstack获取应用线程快照

   # 1.服务器上找一下文件在哪
   [root@iZ2ze616zb6x1rqtgc7w9qZ ~]# which java
   /home/jdk8/jdk1.8.0_271/bin/java
   [root@iZ2ze616zb6x1rqtgc7w9qZ ~]# cd /home/jdk8/jdk1.8.0_271/bin/
   [root@iZ2ze616zb6x1rqtgc7w9qZ bin]# ls |grep jstack
   jstack
   
   # 2.查看应用的进程ID：23417
   [root@iZ2ze616zb6x1rqtgc7w9qZ bin]# ps -ef|grep ruoyi
   root     20580 20029  0 16:02 pts/0    00:00:00 grep --color=auto ruoyi
   root     23417     1  0 Jul19 ?        00:42:48 java -Xms128m -Xmx512m -jar ruoyi-admin.jar
   
   # 3.生成线程快照
   [root@iZ2ze616zb6x1rqtgc7w9qZ bin]# jstack -l 23417 > /home/ruoyi-dump.txt

2. 查看ruoyi-dump.txt文件中定时任务线程状态和发生问题的代码位置

   "pool-2-thread-16" #66 prio=5 os_prio=0 tid=0x00007f92a0003000 nid=0x541b waiting on condition [0x00007f9265743000]
      java.lang.Thread.State: TIMED_WAITING (sleeping)
   	at java.lang.Thread.sleep(Native Method)
   	at com.suwell.ofd.custom.agent.HTTPAgent.convert(HTTPAgent.java:167)
   	at com.suwell.ofd.custom.agent.ConvertAgent.convert(ConvertAgent.java:494)
   	at com.jiangk.apilicense.service.CreateOfdService.makeOFD(CreateOfdService.java:595)
   	at com.jiangk.apilicense.service.CreateOfdService$$FastClassBySpringCGLIB$$9bc09320.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.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
   	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
   	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
   	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
   	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673)

3. 根据第二步可以定位定时任务卡死在CreateOfdService.java:595行

   ...
   Packet packet = new Packet(PackType.COMMON, Target.OFD);
   packet.file(new Common(null, "ofd", new FileInputStream(srcfile_final)));
   packet.seal("Suwell_WebOES", null,seal);
   # 这个方法是调用外部服务生成OFD文件，一直没有相应导致定时任务卡死。
   haseal.convert(packet,new FileOutputStream(ofdoutpath_final));
   ...

解决办法

• 调用外部请求增加超时处理，示例

  			// 为外部请求创建一个单线程
  	    	ExecutorService executor = Executors.newSingleThreadExecutor();
  	        Callable<String> call = new Callable<String>() {
  	            @Override
  	            public String call() throws Exception {
  	                //开始执行耗时操作
  	            	haseal.convert(packet, new FileOutputStream(ofdoutpath_final));
  	                return "证照转换方法“haseal.convert”执行执行完成!";
  	            }
  	        };
  	        try {
  	            Future<String> future = executor.submit(call);
  	            future.get(1000 * 10, TimeUnit.MILLISECONDS); //任务处理超时时间设为 10 秒
  	        } catch (TimeoutException ex) {
  	            System.out.println("OFD转换服务处理超时....");
  	            throw new ResourceNotFoundException(gridDataDTO.getIdcard() + " OFD转换服务调用超时！");
  	        }finally {
  	            // 关闭线程池
  	            executor.shutdown();
              }