报错如下：
java.io.FileNotFoundException: E:\apache-tomcat-8.0.37\webapps\20161028-FileUpLoad\WEB-INF\files\14779134039341184.doc (系统找不到指定的路径。)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
at java.io.FileOutputStream.<init>(FileOutputStream.java:101)
at com.tt.javaweb.fileupload.app.servlet.FileUploadServlet.upload(FileUploadServlet.java:189)
at com.tt.javaweb.fileupload.app.servlet.FileUploadServlet.upload(FileUploadServlet.java:175)
at com.tt.javaweb.fileupload.app.servlet.FileUploadServlet.doPost(FileUploadServlet.java:66)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2508)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2497)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
相关代码如下：
调用upload(String filePath, InputStream inputStream)函数时，传入一个filePath进去，在第172行打印的
filePath=E:\apache-tomcat-8.0.37\webapps\20161028-FileUpLoad\WEB-INF\files\\1477913839796983.doc正确。
但是传入到upload(String filePath, InputStream inputStream)获取输出流时在第186行报错，报错如下：
原因分析：按正常情况，FileOutputStream文件输出流会根据传入的文件名将输出流写入到该文件里，如果该文件不存在那么也会自动创建该文件。所以这里不应该存在找不到文件的问题，代码应该不存在问题。
解决办法：重新开启Eclipse软件就没有报错了。
转载于:https://www.cnblogs.com/TTTTT/p/6017129.html