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://xiazai.jb51.net/201608/yuanma/javawebfileupload(jb51.net).rar

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>

3.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"); }}

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