applet文件上传下载

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js调用applet实现上传下载（1）2009-09-24 10:09用js调用applet实现文件的上传，下载。

1.上传的代码：

applet代码：

package applet;

import java.applet.Applet;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

//本地文件上传（与Servlet交互）
public class AppInt extends Applet {

private String filePath;
private String fileName;
private String url;

private boolean bl=false;
public String getFilePath() {
   return filePath;
}

public void setFilePath(String filePath) {
   this.filePath = filePath;
   System.out.println(this.filePath);
}

public String getFileName() {
   return fileName;
}

public void setFileName(String fileName) {
   this.fileName = fileName;
   System.out.println(this.fileName);
}

public String getUrl() {
   return url;
}

public void setUrl(String url) {
   this.url = url;
   System.out.println(this.url);
}

public void setBl(){
   this.bl=true;
   System.out.println(this.bl);
   send();
}

public void init() {
   if(this.bl){
    send();
   }
}

public void send() {
   {

    try {
     String filePath=getFilePath();
     String fileName =getFileName();
     String urlstring=getUrl();

     System.out.println(filePath+"*****");
    //网络路径很重要
    URL url1 = new URL(urlstring+"?fileName="+URLEncoder.encode(fileName,"utf-8"));

    //打开打开SOCKET链接

     HttpURLConnection conn = (HttpURLConnection) url1
     .openConnection();
   conn.setRequestMethod("POST");
   conn.setAllowUserInteraction(true);
   conn.setDoInput(true);
   conn.setDoOutput(true);
   conn.setUseCaches(true);
   conn.setRequestProperty("Content-Type", "application/octet-stream");


   File jpgFile = new File(filePath);
   if (jpgFile.isFile()) {
    // 建立文件的输入流
    FileInputStream fileInputStream = null;
    fileInputStream = new FileInputStream(jpgFile);
    BufferedInputStream bis = new BufferedInputStream(
      fileInputStream);
    OutputStream os = conn.getOutputStream();
    BufferedOutputStream bos = new BufferedOutputStream(os);
    int len = 0;
    byte[] bty = new byte[4096];
    while ((len = bis.read(bty, 0, 4096)) != -1) {
     bos.write(bty, 0, len);
     bos.flush();

    }
    bos.close();
    bis.close();
    System.out.println(conn.getContentType() + ": "+ conn.getResponseCode());
   }
    } catch (Exception e) {
     e.printStackTrace();

    }

   }
}
}

对应的Servlet代码：

package servlet;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Calendar;

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

import com.DB.DBconnect;

public class Receive extends HttpServlet {

public Receive() {
   super();
}

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 {

}

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

   // PrintWriter out=response.getWriter();
   InputStream in = request.getInputStream();
         //System.out.print("qqqq");



   String name=new String(request.getParameter("fileName").getBytes(),"utf-8");

   String nn=new String(name.getBytes("ISO8859-1"),"utf-8");
   System.out.println("文件名："+name+"******"+nn);

   String tr=name.substring(name.lastIndexOf("."),name.length());

   // 根据时间得文件名
     Calendar calendar = Calendar.getInstance();
     String filename = String.valueOf(calendar.getTimeInMillis())
       +tr;

   System.out.println("服务器，文件名："+name);

         File f = new File("C:\\imgrec\\"+filename);
         String path="c:/imgrec/"+filename;
         FileOutputStream fos = new FileOutputStream(f);

          byte[] b = new byte[1024 * 1024];
          int bytes, sumBytes = 0;

          while (true) {
              bytes = in.read(b);
              if (bytes <= 0)
                  break;
              sumBytes += bytes;
              fos.write(b, 0, bytes);
          }
          fos.close();
          in.close();


          /*
           * 保存上传记录
           */
          DBconnect dao=new DBconnect();
          String sql="insert into fileList(fileName,filePath,name) values('"+filename+"','"+path+"','"+name+"')";
          dao.save(sql);
          dao.close();

         }

public void init() throws ServletException {
}

}

JSP页面：

<%@ page language="java" import="java.util.*,applet.GLAppInt" pageEncoding="utf-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>


    <title>test.jsp</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">

</head>

<body >
<APPLET   CODE = "applet.GLAppInt.class" archive="applet.jar" height="90%" MAYSCRIPT>
<param name="path" value="E:\test\upload">
</APPLET>
<script type="text/javascript">
function saveHtml(){
var filePath=document.applets[0].getAn();
var fileName=document.applets[0].getName();
//alert(fileName);
document.location="show.jsp?filePath="+filePath+"&fileName="+fileName;
}

</script>

</body>

</html>

//*************************

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
    <base href="<%=basePath%>">

    <title>My JSP 'show.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">


</head>

<body>


    <%
   String url=request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+"/appUpFile/servlet/Receive" ;
   String filePath=request.getParameter("filePath");

   if(filePath.length()>0){
   String fileName=request.getParameter("fileName");
   String[] fPath=filePath.split(",");
   String[] fName=fileName.split(",");


   %>
   <div>
    <APPLET   CODE = "applet.AppInt.class" archive="ctr.jar" mayscript height="1" width="1">
        </APPLET>
    <script type="text/javascript">
    function tsb(n){
      var fn=document.getElementById('fn'+n).value;
      var fp=document.getElementById('fp'+n).value;
      var ul='<%=url%>';
     document.applets[0].setFileName(fn);
     document.applets[0].setFilePath(fp);
     document.applets[0].setUrl(ul);
     document.applets[0].setBl();
    }
   </script>
   </div>

   <div align='center'>本地文件上传</div>
    <form action="">
    <table>
    <tr>
    <td>文件名</td>
    <td>路径</td>
    <td>上传</td>
    </tr>
    <%
    for(int i=0;i<fName.length;i++){
   String fp=new String(fPath[i].getBytes("ISO-8859-1"),"utf-8");
    String fn=new String(fName[i].getBytes("ISO-8859-1"),"utf-8");

    %>
    <tr>
    <td><input type="hidden" name="fn<%=i %>" id="fn<%=i %>" value="<%=fn %>"><%=fn %></td>
    <td><input type="hidden" name="fp<%=i %>" id="fp<%=i %>" value="<%=fp %>"><%=fp %></td>
    <td><input type="button" name="sb" value="上传" onclick="tsb('<%=i %>')">
    </td>
    </tr>
    <%
    }
    %>
    </table>
    </form>
<%
}
%>

</body>
</html>

数据库设计：

fileList表：有4个字段 id，fileName,filePath ,name

package com.DB;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DBconnect {
public static Connection conn = null;

public DBconnect() {
   this.conn = getMySqlConnection();
}

public static Connection getMySqlConnection() {
   String url = null;
   try {
    Class.forName("com.mysql.jdbc.Driver");
    url = "jdbc:mysql://localhost:3306/listenle?useUnicode=true&characterEncoding=UTF-8";
    conn = DriverManager.getConnection(url, "root", "rufeng8848");
   } catch (Exception e) {
    e.printStackTrace();
   }
   return conn;
}

/*
* 插入表fileList 给每一次上传的文件做好记录
* 记录上传
*/
public void save(String sql){
   Statement st=null;

   try {
    st=conn.createStatement();
    st.execute(sql);
   } catch (SQLException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
}
/*
* 取出fileList表中文件名，路径
* 便于下载
* 返回类型为
*/
public ResultSet findAll(){
   ResultSet rs=null;
   Statement st=null;
   String sql="select * from fileList";
   try {
    st=conn.createStatement();
    rs=st.executeQuery(sql);
   } catch (SQLException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
   return rs;
}
/*
* 关闭链接
*/
public void close() {
   try {
    conn.close();
   } catch (SQLException e) {
    e.printStackTrace();
    System.out.println("关闭异常");
   }
}
}
这样就可以上传了。

经过测试发现，JS调用applet报java.security.accesscontrolexception异常。

原来是安全机制的问题。在客户端修改一下java的安全机制就可以了。

　　总结：在文件的传输中是流的形式存在的，在硬盘上是文件的形式存在的。我们要做的只是通过HttpServletRequest和HttpServletResponse，或者是response和request来发送流和读取流。以及把文件转换成流或把流转换成文件的操作。

--------------------编程问答-------------------- 怎么没有看到下载的呢？

补充：Java ,  Java相关