commons fileUpload：在 Web 应用程序上下文中指定上传目录

Question

我想知道如何指定上传目录，最好是我要存储上传文件的 WEB-CONTENT 目录下的目录的相对路径：当我指定上传存储为：

**File saveFile = new File("/"+fileName);** please refer to code below

错误：

INFO: Server startup in 497 ms
java.io.IOException: The system cannot find the path specified
 at java.io.WinNTFileSystem.createFileExclusively(Native Method)
 at java.io.File.createNewFile(Unknown Source)
 at controller.UploadServlet.processUploadedFile(UploadServlet.java:86)
 at controller.UploadServlet.doPost(UploadServlet.java:61)
 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 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:128)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
 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:849)
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
 at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
 at java.lang.Thread.run(Unknown Source)
java.io.IOException: Access is denied
 at java.io.WinNTFileSystem.createFileExclusively(Native Method)
 at java.io.File.createNewFile(Unknown Source)
 at controller.UploadServlet.processUploadedFile(UploadServlet.java:86)
 at controller.UploadServlet.doPost(UploadServlet.java:61)
 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 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:128)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
 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:849)
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
 at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
 at java.lang.Thread.run(Unknown Source)

我的代码：

**
 * Instantiates SempediaHome Controller
 */
public class UploadServlet extends HttpServlet {

 /**
  * 
  * @param
  * @return
  */
 public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {

  // Create a factory for disk-based file items
  DiskFileItemFactory factory = new DiskFileItemFactory();

  // Set factory constraints
  //factory.setSizeThreshold(yourMaxMemorySize);
  factory.setRepository(new File("/tmp"));

  // Create a new file upload handler
  ServletFileUpload upload = new ServletFileUpload(factory);

  // Set overall request size constraint
  //upload.setSizeMax(yourMaxRequestSize);

  // Parse the request
  try {
   List /* FileItem */ items = upload.parseRequest(request);
   Iterator iter = items.iterator();
   while (iter.hasNext()) {
       FileItem item = (FileItem) iter.next();

       if (item.isFormField()) {
           this.processFormField(item);
       } else {
           this.processUploadedFile(item);
       }
   }
  } catch (FileUploadException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

 /**
  * 
  * @param
  * @return
  */
 public void processUploadedFile(FileItem item) throws IOException {

  // Process a file upload
  if (!item.isFormField()) {
      //String fieldName = item.getFieldName();
      String fileName = item.getName();
      //String contentType = item.getContentType();
      //boolean isInMemory = item.isInMemory();
      //long sizeInBytes = item.getSize();     
      try {
       File saveFile = new File("/"+fileName);
       saveFile.createNewFile();
    item.write(saveFile);
   } catch (Exception e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  }
 }

 /**
  * 
  * @param
  * @return
  */
 public void processFormField(FileItem item) {

 }

}

Answer 1

在您的 servlet（或 jsp）中：

String contextRoot = getServletContext().getRealPath("/")

返回上下文根。所以：（

factory.setRepository(new File(contextRoot + "WEB-INF/tmp"));

你最好不要将tmp目录放在可以通过网络访问的地方）

你的异常意味着你当前的操作系统用户没有写入目标目录的权限。确保它具有所需目录的写权限。