JavaWeb文件上传开发实例

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：

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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