一 问题：

  今天收到告警邮件：

2017-02-27 10:21:29 <br></br>参数: *********** status=0 <br></br>异常:org.springframework.dao.DataIntegrityViolationException: ### Error updating database. Cause: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Incorrect datetime value: '19719700-01-01 00:01:00' for column 'excu_date' at row 1 ### The error may involve com.bj58.daojia.crm.crmCustom.ext.CrmCustomPushExtDao.insert-Inline ### The error occurred while setting parameters ### SQL: insert into ************ values (?, ?, ?, ?, ?,?) ### Cause: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Incorrect datetime value: '19719700-01-01 00:01:00' for column 'excu_date' at row 1 ; SQL []; Data truncation: Incorrect datetime value: '19719700-01-01 00:01:00' for column 'excu_date' at row 1; nested exception is com.mysql.jdbc.MysqlDataTruncation: Data truncation: Incorrect datetime value: '19719700-01-01 00:01:00' for column 'excu_date' at row 1<br></br>org.springframework.jdbc.support.SQLStateSQLExceptionTranslator.doTranslate(SQLStateSQLExceptionTranslator.java:100) org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:73) org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81) org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81) org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:71) org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:365) $Proxy38.insert(Unknown Source) org.mybatis.spring.SqlSessionTemplate.insert(SqlSessionTemplate.java:237) org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:79) org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:40) $Proxy83.insert(Unknown Source) sun.reflect.GeneratedMethodAccessor931.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) java.lang.reflect.Method.invoke(Method.java:597) org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317) org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:85) com.bj58.daojia.crm.helper.utils.ExceptionHandleUtil.around(ExceptionHandleUtil.java:40) sun.reflect.GeneratedMethodAccessor107.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) java.lang.reflect.Method.invoke(Method.java:597) org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621) org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610) org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:68) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) $Proxy84.insert(Unknown Source) com.bj58.daojia.crm.crmCustom.service.impl.IcrmCustomPushService.insert(IcrmCustomPushService.java:44) sun.reflect.GeneratedMethodAccessor1007.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) java.lang.reflect.Method.invoke(Method.java:597) org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317) org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:85) com.bj58.daojia.crm.helper.utils.ExceptionHandleUtil.around(ExceptionHandleUtil.java:40) sun.reflect.GeneratedMethodAccessor107.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) java.lang.reflect.Method.invoke(Method.java:597) org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621) org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610) org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:68) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) $Proxy85.insert(Unknown Source) com.bj58.daojia.crm.crmCustomService.controller.CrmCustomServiceController.deletePosition(CrmCustomServiceController.java:363) com.bj58.daojia.crm.crmCustomService.controller.CrmCustomServiceController$$FastClassBySpringCGLIB$$d71598e4.invoke(<generated>) org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:708) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:85) com.bj58.daojia.crm.helper.utils.ExceptionHandleUtil.around(ExceptionHandleUtil.java:40) sun.reflect.GeneratedMethodAccessor107.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) java.lang.reflect.Method.invoke(Method.java:597) org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621) org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610) org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:68) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644) com.bj58.daojia.crm.crmCustomService.controller.CrmCustomServiceController$$EnhancerBySpringCGLIB$$59368b1a.deletePosition(<generated>) sun.reflect.GeneratedMethodAccessor2053.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) java.lang.reflect.Method.invoke(Method.java:597) org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863) javax.servlet.http.HttpServlet.service(HttpServlet.java:647) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) javax.servlet.http.HttpServlet.service(HttpServlet.java:728) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) com.bj58.daojia.crm.filter.ControllerFilter.doFilter(ControllerFilter.java:29) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) com.bj58.daojia.sso.filter.LoginFilter.doFilter(LoginFilter.java:58) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) com.daojia.spat.dtracker.springmvc.plugin.TrakerPlugin.doFilter(TrakerPlugin.java:118) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222) org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953) org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310) java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) java.lang.Thread.run(Thread.java:662) 出错原因，告警邮件上面写的比较明确了，就是往数据库插入数据的时候，“执行时间”数据异常校验不过，导致异常。

二 分析：

  为啥异常呢？看下对应代码： 

@Autowired CrmCustomPushExtDao crmCustomPushExtDao; private static DateFormat df = new SimpleDateFormat("yyyy-mm-dd"); private static final Logger log = LoggerFactory.getLogger(IcrmCustomPushService.class); @Override public int insert(Long customId,Integer type) { //1新增 2删除 CrmCustomPush crmCustomPush=new CrmCustomPush(); crmCustomPush.setCustomId(customId); crmCustomPush.setStatus(0);//待处理 crmCustomPush.setCreateDate(new Date()); crmCustomPush.setCustomType(type); try { Date excuDate=df.parse("1970-01-01"); crmCustomPush.setExcuDate(excuDate); } catch (ParseException e) { e.printStackTrace(); } List<CrmCustomPush> crmCustomPushs=crmCustomPushExtDao.selectByCustomId(customId); if(crmCustomPushs.size()>0){ log.error("已存在商家id未推送："+customId); }else { crmCustomPushExtDao.insert(crmCustomPush); } return 1;对比一下，就发现这个异常的字段不是页面传入的，排除了入参校验不严问题。那就落在 Date excuDate=df.parse("1970-01-01");

这一行上了，我们知道要尽量少的创建SimpleDateFormat实例对象，每次处理一个时间信息的时候，就需要创建一个SimpleDateFormat实例对象，然后再丢弃这个对象，耗费内存。所以这段代码里面改了为静态的方法。结合日志来看，不是每次都有问题，有时候抛异常就怀疑是并发问题。

那么可以验证下自己的想法：

。。。。 public static void main(String[] agrs){ ExecutorService tmpool = Executors.newFixedThreadPool(100); for(int i=0;i<100;i++) { Thread t1 = new MyThread(); tmpool.execute(t1); } tmpool.shutdown(); System.out.println("pool close"); } public static Date getDate(){ try { return df.parse("1970-01-01"); } catch (ParseException e) { // TODO Auto-generated catch block System.out.println(e.getMessage()); e.printStackTrace(); } return null; } } class MyThread extends Thread { @Override public void run() { System.out.println(Thread.currentThread().getName() + ":date:"+IcrmCustomPushService.getDate()); } }

可以看到问题复现，比如时间不一致，报错线程启动异常等。

at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1514) at java.text.DateFormat.parse(DateFormat.java:364) at com.bj58.daojia.crm.crmCustom.service.impl.IcrmCustomPushService.getDate(IcrmCustomPushService.java:81) at com.bj58.daojia.crm.crmCustom.service.impl.MyThread.run(IcrmCustomPushService.java:94) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Exception in thread "pool-1-thread-40" java.lang.NumberFormatException: For input string: "" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) at java.lang.Long.parseLong(Long.java:601) at java.lang.Long.parseLong(Long.java:631) at java.text.DigitList.getLong(DigitList.java:195) at java.text.DecimalFormat.parse(DecimalFormat.java:2051) at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:1869) at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1514) at java.text.DateFormat.parse(DateFormat.java:364) at com.bj58.daojia.crm.crmCustom.service.impl.IcrmCustomPushService.getDate(IcrmCustomPushService.java:81) at com.bj58.daojia.crm.crmCustom.service.impl.MyThread.run(IcrmCustomPushService.java:94) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) java.lang.NumberFormatException: For input string: "" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) at java.lang.Long.parseLong(Long.java:601) at java.lang.Long.parseLong(Long.java:631) at java.text.DigitList.getLong(DigitList.java:195) at java.text.DecimalFormat.parse(DecimalFormat.java:2051) at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:2162) at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1514) at java.text.DateFormat.parse(DateFormat.java:364) at com.bj58.daojia.crm.crmCustom.service.impl.IcrmCustomPushService.getDate(IcrmCustomPushService.java:81) at com.bj58.daojia.crm.crmCustom.service.impl.MyThread.run(IcrmCustomPushService.java:94) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) java.lang.NumberFormatException: For input string: "" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) at java.lang.Long.parseLong(Long.java:601) at java.lang.Long.parseLong(Long.java:631) at java.text.DigitList.getLong(DigitList.java:195) at java.text.DecimalFormat.parse(DecimalFormat.java:2051) at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:2162) at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1514) at java.text.DateFormat.parse(DateFormat.java:364) at com.bj58.daojia.crm.crmCustom.service.impl.IcrmCustomPushService.getDate(IcrmCustomPushService.java:81) at com.bj58.daojia.crm.crmCustom.service.impl.MyThread.run(IcrmCustomPushService.java:94) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Exception in thread "pool-1-thread-35" java.lang.NumberFormatException: multiple points at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1890) at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110) at java.lang.Double.parseDouble(Double.java:538) at java.text.DigitList.getDouble(DigitList.java:169) at java.text.DecimalFormat.parse(DecimalFormat.java:2056) at java.text.SimpleDateFormat.subParse(SimpleDateFormat.java:1869) at java.text.SimpleDateFormat.parse(SimpleDateFormat.java:1514) at java.text.DateFormat.parse(DateFormat.java:364) at com.bj58.daojia.crm.crmCustom.service.impl.IcrmCustomPushService.getDate(IcrmCustomPushService.java:81) at com.bj58.daojia.crm.crmCustom.service.impl.MyThread.run(IcrmCustomPushService.java:94) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) pool-1-thread-39:date:Thu Jan 01 00:01:00 CST 1970 pool-1-thread-88:date:Thu Jan 01 00:01:00 CST 1970 pool-1-thread-33:date:Thu Jan 01 00:01:00 CST 1970 pool-1-thread-30:date:Thu Jan 01 00:01:00 CST 1970 pool-1-thread-29:date:Thu Jan 01 00:01:00 CST 1970 pool-1-thread-26:date:Thu Jan 01 00:01:00 CST 1970 pool-1-thread-86:date:Thu Jan 01 00:01:00 CST 1970 pool-1-thread-25:date:Tue Sep 11 00:00:00 CST 4981 pool-1-thread-21:date:Sat Jan 01 00:01:00 CST 11000000 pool-1-thread-18:date:Mon Jan 11 00:11:00 CST 19719700 pool-1-thread-90:date:Mon Jan 11 00:11:00 CST 19719700 pool-1-thread-17:date:Mon Jan 11 00:11:00 CST 19719700

三 解决：

既然定位是容易忽视的并发的问题，我们看下jdk文档介绍：

这个太隐蔽了，不熟悉的容易忽略掉，因为习惯了使用工程中的dateutil来处理代码的问题。

看一下代码：

                start = subParse(text, start, tag, count, obeyCount,                                  ambiguousYear, pos,                                  useFollowingMinusSignAsDelimiter, calb);

大概实现思路就是根据截取字符串，给calendar设置,我理解就是多个线程同时拥有程持有了同一个SimpleDateFormat的实例，分别调用parse方法，

线程1处理部分，设置calendar值。中断。

线程2处理部分，设置calendar值。中断。线程1再来calendar值已经被修改了，就会引发各种问题。

解决方法：

1.创建新实例。

 DateFormat df = new SimpleDateFormat("yyyy-mm-dd")

 Date excuDate=df.parse("1970-01-01");

优点：将有线程安全问题的对象由共享变为局部私有都能避免多线程问题，

缺点：不过也加重了创建对象的负担。一般情况影响不大，尤其是负载不高的时候。

2. 同步：

可以看见打到效果，线程执行的不是顺序的，看结果即可。

缺点：高并发时有一定性能问题。

3.不用jdk,改为其他线程安全的类，比如：apache的commons-lang包的DateUtils和DateFormatUtils类，这两个类的方法是线程安全的。

4. threadlocal

private static ThreadLocal<DateFormat> df = new ThreadLocal<DateFormat>(){ @Override protected DateFormat initialValue() { return new SimpleDateFormat("yyyy-mm-dd"); } }; public static void main(String[] agrs){ ExecutorService tmpool = Executors.newFixedThreadPool(100); for(int i=0;i<100;i++) { Thread t1 = new MyThread(); tmpool.execute(t1); } tmpool.shutdown(); System.out.println("pool close"); } public static Date getDate(){ try { return df.get().parse("1970-01-01"); } catch (ParseException e) { // TODO Auto-generated catch block System.out.println(e.getMessage()); e.printStackTrace(); } return null; } } class MyThread extends Thread { @Override public void run() { System.out.println(Thread.currentThread().getName() + ":date:"+IcrmCustomPushService.getDate()); } }

对比下同步机制：线程局部变量（threadlocal）本质上是线程对应一个map，map的key就是threadLocal，而值就是我们set的那个值，每次线程在get的时候，都从自己的变量中取值，既然从自己的变量中取值，那肯定就不存在线程安全问题，总体来讲，对比同步方式就是：空间换取时间。

可以结合源码看看背后实现。