启动后请求报错，不清楚原因
2021-01-05 13:31:47 [http-nio-8083-exec-2] ERROR org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/].[dispatcherServlet] -Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.multipart.MultipartException: Failed to parse multipart servlet request; nested exception is java.io.IOException: org.apache.tomcat.util.http.fileupload.FileUploadException: Stream closed] with root cause
java.io.IOException: Stream closed
at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:359)
at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:132)
at java.io.FilterInputStream.read(FilterInputStream.java:133)
at org.apache.tomcat.util.http.fileupload.util.LimitedInputStream.read(LimitedInputStream.java:132)
at org.apache.tomcat.util.http.fileupload.MultipartStream$ItemInputStream.makeAvailable(MultipartStream.java:977)
at org.apache.tomcat.util.http.fileupload.MultipartStream$ItemInputStream.read(MultipartStream.java:881)
at java.io.InputStream.read(InputStream.java:101)
at org.apache.tomcat.util.http.fileupload.util.Streams.copy(Streams.java:98)
at org.apache.tomcat.util.http.fileupload.util.Streams.copy(Streams.java:68)
at org.apache.tomcat.util.http.fileupload.MultipartStream.readBodyData(MultipartStream.java:572)
at org.apache.tomcat.util.http.fileupload.MultipartStream.discardBodyData(MultipartStream.java:596)
at org.apache.tomcat.util.http.fileupload.MultipartStream.skipPreamble(MultipartStream.java:614)
at org.apache.tomcat.util.http.fileupload.impl.FileItemIteratorImpl.findNextItem(FileItemIteratorImpl.java:213)
at org.apache.tomcat.util.http.fileupload.impl.FileItemIteratorImpl.<init>(FileItemIteratorImpl.java:127)
at org.apache.tomcat.util.http.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:256)
at org.apache.tomcat.util.http.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:280)
at org.apache.catalina.connector.Request.parseParts(Request.java:2869)
at org.apache.catalina.connector.Request.getParts(Request.java:2771)
at org.apache.catalina.connector.RequestFacade.getParts(RequestFacade.java:1098)
at javax.servlet.http.HttpServletRequestWrapper.getParts(HttpServletRequestWrapper.java:359)
at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.parseRequest(StandardMultipartHttpServletRequest.java:95)
at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.<init>(StandardMultipartHttpServletRequest.java:88)
at org.springframework.web.multipart.support.StandardServletMultipartResolver.resolveMultipart(StandardServletMultipartResolver.java:87)
at org.springframework.web.servlet.DispatcherServlet.checkMultipart(DispatcherServlet.java:1178)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1012)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:626)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at com.chinamobile.cmss.zdhcspt.common.config.FilterConfig.doFilter(FilterConfig.java:33)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:94)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
严重: Servlet.service() for servlet jsp threw exception。出现此错误一般都是在jsp中使用了输出流，没有妥善处理好的原因。
原因：
在tomcat中jsp编译成servlet之后在函数_jspService(HttpServletRequest request, HttpServletResponse response)的最后
有一段这样的代码
finally {
if (_jspxFactory != null) _jspxFactory.releasePageContext(_jspx_page_context);
}
这里是在释放在jsp中使用的对象，会调用response.getWriter(),因为这个方法是和
response.getOutputStream()相冲突的！所以会出现以上这个异常。
解决的办法
在使用完输出流以后调用以下两行代码即可：
out.clear();
out = pageContext.pushBody();
java.io.IOException: Stream closed出现这个异常的原因：举个例子
BufferedReader Input1 = new BufferedReader(new InputStreamReader(System.in));
BufferedReader Input2 = new BufferedReader(new InputStreamReader(System.in));
这两句话中的Input1和Input2都是由System.in封装而来。这是设计模式中的装饰模式的应用，顾名思义，装饰模式就是对最原始的东西进行装饰，只改变了外表，但实质并没有改变。System.in就是最原始的东西，Input1和Input2只是他被装饰后的外表，所以程序中的Input1和Input2的实质上都是System.in。调用Input1.close()，会自动调用Input1的实质System.in.close(),所以对于Input2来说他的实质System.in已经关闭掉，所以...