Java开发之文件上传

文件上传有SmartUpload、Apache的Commons fileupload.我们今天介绍Commons fileupload的用法。

1.commons-fileupload-1.3.1.jar

下载地址：http://pan.baidu.com/s/1kVtYMzH

2.web.xml

 <!-- 上传文件 服务器端 -->
   <servlet>
     <servlet-name>UploadServlet</servlet-name>
     <servlet-class>com.servlet.UploadServlet</servlet-class>
     <init-param>
     <param-name>filePath</param-name><!-- 文件存储路径 -->
     <param-value>F:\myeclipse\Workspaces\King\WebRoot\uploadfile\</param-value>
     </init-param>
   </servlet>

   <servlet-mapping>
     <servlet-name>UploadServlet</servlet-name>
     <url-pattern>/servlet/UploadServlet</url-pattern>
   </servlet-mapping>

3.UploadFile.jsp

 <form action="servlet/UploadServlet" method="post" enctype="multipart/form-data">
         <div align="center">
             <fieldset style="width:80%">
                 <legend>上传文件</legend><br/>
                     <div align="left">上传文件1</div>
                     <div align="left">
                         <input type="file" name="file1"/>
                     </div>
                     <div align="left">上传文件2</div>
                     <div align="left">
                         <input type="file" name="file2"/>
                     </div>
                     <div>
                         <div align='left'>上传文件说明1</div>
                         <div align='left'><input type="text" name="description1"/></div>
                     </div>
                     <div>
                         <div align='left'>上传文件说明2</div>
                         <div align='left'><input type="text" name="description2"/></div>
                     </div>
                     <div>
                         <div align='left'>
                             <input type='submit' value="上传文件"/>
                         </div>
                     </div>
             </fieldset>
         </div>
     </form>

4.servlet

 package com.servlet;

 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.io.PrintWriter;
 import java.util.List;

 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import org.apache.commons.fileupload.DiskFileUpload;
 import org.apache.commons.fileupload.FileItem;
 import org.apache.commons.fileupload.FileUploadException;

 import sun.swing.FilePane;

 public class UploadServlet extends HttpServlet {

     private String filePath;

     /**
      * Destruction of the servlet. <br>
      */
     public void destroy() {
         super.destroy(); // Just puts "destroy" string in log
         // Put your code here
     }

     public void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {

         response.setCharacterEncoding("UTF-8");
         response.getWriter().println("请以POST方式上传文件");
     }

     public void doPost(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         File file1 = null, file2 = null;
         String description1 = null, description2 = null;
         response.setCharacterEncoding("UTF-8");
         request.setCharacterEncoding("UTF-8");
         response.setContentType("text/html");
         PrintWriter out = response.getWriter();

         DiskFileUpload diskFileUpload = new DiskFileUpload();//解析request

         try {
             List<FileItem> fileList = diskFileUpload.parseRequest(request);//将结果放置到List中
             out.println("遍历所有的FileItem...</br>");
             this.log("遍历所有的FileItem...");
             for(FileItem fileItem : fileList){
                 if(fileItem.isFormField()){//如果是文本域
                     if("description1".equals(fileItem.getFieldName())){
                         out.println("遍历到description1...</br>");
                         description1 = new String(fileItem.getString().getBytes(),"UTF-8");
                     }
                     if("description2".equals(fileItem.getFieldName())){
                         out.println("遍历到description2...</br>");
                         description2 = new String(fileItem.getString().getBytes(),"UTF-8");
                     }
                 }else{//否则为文件域
                     if("file1".equals(fileItem.getFieldName())){
                         File remoteFile = new File(new String(fileItem.getName().getBytes(),"UTF-8"));
                         out.println("遍历到file1...</br>");
                         out.println("客户端文件位置："+remoteFile.getAbsolutePath()+"</br>");
                         //服务器端文件，放在uploadfile文件夹下
                         file1 = new File(filePath,remoteFile.getName());
                         file1.getParentFile().mkdirs();//创建文件夹路径
                         file1.createNewFile();//创建新文件
                         InputStream ins = fileItem.getInputStream();//FileItem的内容
                         OutputStream ous = new FileOutputStream(file1);//输出到文件中
                         try{
                             byte[] buffer = new byte[1024];//字节缓存
                             int len = 0;//实际缓存长度
                             while((len=ins.read(buffer)) > -1){//循环读入缓存
                                 ous.write(buffer,0,len);
                             }
                             out.println("已保存文件"+file1.getAbsolutePath()+"</br>");
                         }
                         finally{
                             ous.close();
                             ins.close();
                         }
                     }
                     if("file2".equals(fileItem.getFieldName())){
                         File remoteFile = new File(new String(fileItem.getName().getBytes(),"UTF-8"));
                         out.println("遍历到file2...</br>");
                         out.println("客户端文件位置："+remoteFile.getAbsolutePath()+"</br>");
                         //服务器端文件，放在uploadfile文件夹下
                         file2 = new File(filePath,remoteFile.getName());
                         file2.getParentFile().mkdirs();//创建文件夹路径
                         file2.createNewFile();//创建新文件
                         InputStream ins = fileItem.getInputStream();//FileItem的内容
                         OutputStream ous = new FileOutputStream(file2);//输出到文件中
                         try{
                             byte[] buffer = new byte[1024];//字节缓存
                             int len = 0;//实际缓存长度
                             while((len=ins.read(buffer)) > -1){//循环读入缓存
                                 ous.write(buffer,0,len);
                             }
                             out.println("已保存文件"+file2.getAbsolutePath()+"</br>");
                         }
                         finally{
                             ous.close();
                             ins.close();
                         }
                     }
                 }
             }
             out.println("Request 解析完毕");
         } catch (FileUploadException e) {
             // TODO 自动生成的 catch 块
             out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
             out.println("<HTML>");
             out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");
             out.println("  <BODY>");

             if(file1 != null){
                 out.println("<div>");
                 out.println(" <div align='left'>file1;</div>");
                 out.println(" <div align='left'><a href='"+request.getContextPath()+
                         file1.getName()+"'target=_blank>"+file1.getName()+"</a>");
                 out.println("</div>");
                 out.println("</div>");
             }
             if(file2 != null){
                 out.println("<div>");
                 out.println(" <div align='left'>file2;</div>");
                 out.println(" <div align='left'><a href='"+request.getContextPath()+
                         file2.getName()+"'target=_blank>"+file2.getName()+"</a>");
                 out.println("</div>");
                 out.println("</div>");
             }
             out.println("<div>");
             out.println(" <div align='left'>description1:</div>");
             out.println(" <div align='left'>");
             out.println(description1);
             out.println("</div>");
             out.println("</div>");

             out.println("<div>");
             out.println(" <div align='left'>description2:</div>");
             out.println(" <div align='left'>");
             out.println(description2);
             out.println("</div>");
             out.println("</div>");

             out.println("  </BODY>");
             out.println("</HTML>");
             out.flush();
             out.close();
         }

     }

     public String getServletInfo() {
         return "This is my default servlet created by Eclipse";
     }

     public void init() throws ServletException {
         // Put your code here
         filePath = getServletConfig().getInitParameter("filePath");
     }

 }

6.