[Java基础]Java异常捕获

在Java中，异常分为二类：Error和Exception, Exception是运行时异常，Error是JVM内部错误，捕获Exception没法捕获Error

Throwable
 |      |
Error   Exception
        |
        RuntimeException

今天我在项目中就遇到了一个问题，如下：

try {
                    //更新log
                    PullUpdateLogVO vo = new PullUpdateLogVO();
                    vo.setNotifyId(notification.getNotifyId());
                    vo.setQueryStatus(pullDataResult != null ? pullDataResult.getStatus() : 3);
                    vo.setQueryTime(queryTime);
                    vo.setRespSerial(pullDataResult != null ? pullDataResult.getRespSerial() : "");
                    vo.setUserid(notification.getUserid());
                    String res = getValidateService().pullUpdate(vo);
                    logger.info(String.format("更新任务查询状态成功: log = %s", res));
                } catch (Exception ex) {
                    logger.warn(String.format("更新任务查询状态失败:ex=%s", ex.getMessage()));
                }

打印出异常信息，如下图所示：

Exception in thread "Mq-MqQueueExcutorServiceNew-DataChannel-PullDataNotify-104-3" java.lang.NoSuchMethodError: com.ppdai.cbd.thirdparty.pulldata.common.request.PullUpdateLogVO.setUserid(Ljava/lang/Integer;)V
    at com.ppdai.realtime.datachannel.pullservice.PullNotificationDispatchService.dispatchNotification(PullNotificationDispatchService.java:122)
    at com.ppdai.realtime.datachannel.mq.service.MessageQueueConsumer.onMessageReceived(MessageQueueConsumer.java:51)
    at com.ppdai.infrastructure.mq.client.biz.MqQueueExcutorService.doMessageReceived(MqQueueExcutorService.java:461)
    at com.ppdai.infrastructure.mq.client.biz.MqQueueExcutorService.doDealMsg(MqQueueExcutorService.java:408)
    at com.ppdai.infrastructure.mq.client.biz.MqQueueExcutorService.handleMessage(MqQueueExcutorService.java:369)
    at com.ppdai.infrastructure.mq.client.biz.MqQueueExcutorService.access$600(MqQueueExcutorService.java:48)
    at com.ppdai.infrastructure.mq.client.biz.MqQueueExcutorService$3.run(MqQueueExcutorService.java:308)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

NoSuchMethodError就是典型的JVM内部错误，属于Error的范畴，一般这种问题编译器就应该解决，Java Class编译文件class文件函数找不到错误。Error类层次如下：

 java.lang.Object

• java.lang.Throwable
  • java.lang.Error
    • java.lang.LinkageError
      • java.lang.IncompatibleClassChangeError
        • NoSuchMethodError

解决办法：1.将捕获Exception改成捕获Throwable  2.另一种将依赖包类添加对应方法