Implementation of JSP Servlet File Upload

The implementation of JSP Servlet File Upload is first to prepare the environment and software:

Common-fileupload component

: Http://jakarta.apache.org/commons/fileupload/

Download and unzip the zip package, copy the commons-fileupload-1.0.jar to tomcat's webapps \ your webapp \ WEB-INF \ lib \

Create a servlet

 
 

  
  
Import java. io .*;
  
  
Import java. util .*;
  
  
Import javax. servlet .*;
  
  
Import javax. servlet. http .*;
  
  
Import org. apache. commons. fileupload .*;
  
  
 
  
  
Public class Upload extends HttpServlet {
  
  
 
  
  
Private StringUploadPath="C: \ upload \\"; // Directory used to store uploaded files
  
  
Private StringTempPath="C: \ upload \ tmp \\"; // Directory used to store temporary files
  
  
 
  
  
Public void doPost (HttpServletRequest request, HttpServletResponse response)
  
  
Throws IOException, ServletException
  
  
{
  
  
Try {
  
  
DiskFileUploadFu=NewDiskFileUpload ();
  
  
// Set the maximum file size, which is 4 MB
  
  
Fu. setSizeMax (4194304 );
  
  
// Set the buffer size, which is 4 kb
  
  
Fu. setSizeThreshold (4096 );
  
  
// Set the temporary directory:
  
  
Fu. setRepositoryPath (tempPath );
  
  
 
  
  
// Obtain all objects:
  
  
ListFileItems=Fu. ParseRequest (request );
  
  
IteratorI=FileItems. Iterator ();
  
  
// Process each file in sequence:
  
  
While (I. hasNext ()){
  
  
FileItemFi= (FileItem) I. next ();
  
  
// Get the file name, which includes the path:
  
  
StringFiFileName= Fi. getName ();
  
  
If (fileName! = Null ){
  
  
// User and file information can be recorded here
  
  
//...
  
  
// Write the.txt file. You can also extract the file name from fileName:
  
  
Fi. write (new File (uploadPath + "a.txt "));
  
  
}
  
  
}
  
  
// Jump to the upload success prompt page
  
  
}
  
  
Catch (Exception e ){
  
  
// Jump to the error page
  
  
}
  
  
}
  
  
}
 
 

After the Servlet receives a Post request from the browser, it uploads the file in the doPost () method. The following is the sample code:

To read the specified upload folder in the configuration file, run the following command in the init () method:

 
 

  
  
Public void init () throws ServletException {
  
  
UploadPath= ....
  
  
TempPath= ....
  
  
// The folder is automatically created if it does not exist:
  
  
If (! New File (uploadPath). isDirectory ())
  
  
New File (uploadPath). mkdirs ();
  
  
If (! New File (tempPath). isDirectory ())
  
  
New File (tempPath). mkdirs ();
  
  
}
 
 

Servlet File Upload configuration Servlet, open tomcat \ webapps \ your webapp \ WEB-INF \ web. xml with notepad, if not, create a new one. The typical configuration is as follows:

 
 

  
  
﹤?xml version="1.0" encoding="ISO-8859-1"?﹥  
  
  
﹤!DOCTYPE web-app  
  
  
    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"  
  
  
    "http://java.sun.com/dtd/web-app_2_3.dtd"﹥  
  
  
﹤web-app﹥  
  
  
    ﹤servlet﹥  
  
  
        ﹤servlet-name﹥Upload﹤/servlet-name﹥  
  
  
        ﹤servlet-class﹥Upload﹤/servlet-class﹥  
  
  
    ﹤/servlet﹥  
  
  
    ﹤servlet-mapping﹥  
  
  
        ﹤servlet-name﹥Upload﹤/servlet-name﹥  
  
  
        ﹤url-pattern﹥/fileupload﹤/url-pattern﹥  
  
  
    ﹤/servlet-mapping﹥  
  
  
﹤/web-app﹥ 
 
 

End of Servlet File Upload: After configuring the Servlet, start Tomcat and write a simple html test:

 
 

  
  
﹤form action="fileupload" method="post" enctype="multipart/form-data" name="form1"﹥  
  
  
  ﹤input type="file" name="file"﹥  
  
  
  ﹤input type="submit" name="Submit" value="upload"﹥  
  
  
﹤/form﹥ 
 
 

Note action = "fileupload" where fileupload is the url-pattern specified When configuring the servlet.

So the JSP Servlet File Upload implementation is complete. Do you have any changes in development ideas?

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