[置顶] java.io.IOException: No such file or directory解决方案之权限问题

先贴出异常信息：

java.io.IOException: No such file or directory
        at java.io.UnixFileSystem.createFileExclusively(Native Method)
        at java.io.File.createNewFile(File.java:883)
        at com.bill99.prm.query.controller.FileUploadController.upload(FileUploadController.java:143)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.springframework.web.servlet.mvc.multiaction.MultiActionController.invokeNamedMethod(MultiActionController.java:473)
        at org.springframework.web.servlet.mvc.multiaction.MultiActionController.handleRequestInternal(MultiActionController.java:410)
        at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153)
        at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:809)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571)
        at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:511)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at com.bill99.subintra.controler.SessionFilter.doFilterInternal(SessionFilter.java:86)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at edu.yale.its.tp.cas.client.filter.CASFilter.doFilter(CASFilter.java:457)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:615)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:396)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:662)

出现此类问题的场景很多，我今天在帮项目组解决该问题时发现是在服务器上创建文件夹以及文件时无法创建，经过查证发现是目录所属的用户是root，根本不是我们所用的用户oracle，导致无法创建目录和文件，故而出现了No such file or directory这样的异常。

解决方案如下：

使用chown命令修改文件或目录所属的用户：

命令：chown 用户 目录或文件

例如：chown oracle /xx/yy  (把xx目录下的yy目录的拥有者改为oracle用户) 

附：使用chgrp命令可以修改文件或目录所属的组：

命令：chgrp 组 目录或文件名

例如：chgrp oracle /xx/yy  (把xx目录下的yy目录的所属组改为oracle组)

问题很简单，仅针对入门的兄弟可以参考一下