Servelet:
package com.syit.scmis.common;
import java.io.IOException;
import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* @version 1.0
* @author
*/
public class GetFile
extends HttpServlet
implements Servlet {
/**
* @see javax.servlet.http.HttpServlet#void (javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*/
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
doPost(req,resp);
}
/**
* @see javax.servlet.http.HttpServlet#void (javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*/
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
req.setCharacterEncoding("GBK");
String spath=req.getParameter("path");
if (spath.equals("")){
java.io.PrintWriter out=resp.getWriter();
out.println("Current directory is invalidate!");
}
else{
if (spath.indexOf("/download")==0){
req.setAttribute("parent",spath.substring(1));
spath=getServletContext().getRealPath(spath);
DownloadFile f=new DownloadFile();
if (f.getFileEx(spath,req,resp)==1){
req.getRequestDispatcher("/download.jsp").forward(req,resp);
}
}else{
java.io.PrintWriter out=resp.getWriter();
out.println("Current directory is invalidate!");
}
}
}
}
主要的工作Java类:
/*
* 创建日期 2004-10-13
*
*/
package com.syit.scmis.common;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
/**
*
* @author Fuqiming
* @version 1.0
*
*/
public class DownloadFile {
public int getFileEx(String strpath,HttpServletRequest req,HttpServletResponse resp) throws IOException{
File f=new File(strpath);
if (f.isDirectory()){
req.setAttribute("list",getFile(strpath));
return 1;
}
else if (f.isFile()){
downFile(strpath,req,resp);
return 0;
}else {
throw new IOException("path is invalidate");
}
}
public ArrayList getFile(String strpath){
ArrayList array=new ArrayList();
File f=new File(strpath);
File[] fs=f.listFiles();
for (int i=0;i<fs.length;i++){
array.add(fs[i]);
}
return array;
}
public void downFile(String s,HttpServletRequest req,HttpServletResponse resp) throws IOException{
if (s==null){
throw new IOException("File name is must nt null");
}
File file =new File(s);
if (!file.isFile()){
throw new IOException("File is not exist");
}
System.out.println(req.getRemoteAddr()+"请求下载："+s);
long l=file.length();
long p=0;
resp.reset();
resp.setHeader("Accept-Ranges", "bytes");
if (req.getHeader("Range") != null)
{
resp.setStatus(javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT);
String sclient=req.getHeader("Range");
sclient=sclient.substring("bytes=".length());
if (sclient.charAt(sclient.length()-1)=='-') sclient=sclient.substring(0,sclient.length()-1);
p = Long.parseLong(sclient);
}
resp.setHeader("Content-Length", new Long(l - p).toString());
if (p != 0)
{
resp.setHeader("Content-Range","bytes " + new Long(p).toString() + "-" + new Long(l -1).toString() + "/" + new Long(l).toString());
}
resp.setContentType("application/octet-stream");
resp.setHeader("Content-Disposition",
"attachment;filename="+new String(file.getName().getBytes(),"iso-8859-1"));
long k =0;
int ibuffer=65536;
byte[] bytes=new byte[ibuffer];
FileInputStream fileinputstream = new FileInputStream(file);
try{
if (p!=0) fileinputstream.skip(p);
while (k<l){
int j=fileinputstream.read(bytes,0,ibuffer);
resp.getOutputStream().write(bytes,0,j);
resp.getOutputStream().flush();
k +=j;
}
System.out.println(req.getRemoteAddr()+"请求下载："+s+"下载完毕");
}
catch(Exception e){
System.err.println("传输"+s+"失败,位置:"+k);
System.err.println(e.getMessage());
}
finally{
fileinputstream.close();
}
}
}