基于servlet的文件下载

package org.lyt.util;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

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

@SuppressWarnings("serial")
public class FileDownLoadServlet extends HttpServlet{

@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String path=request.getParameter("filename");
path=new String(path.getBytes("ISO-8859-1"),"utf-8");
download(path,request,response);
}

@SuppressWarnings("deprecation")
public HttpServletResponse download(String path,HttpServletRequest request, HttpServletResponse response) {
try {
// path是指欲下载的文件的路径。
File file = new File(request.getRealPath("/")+"/"+path);
// 取得文件名。
String filename = file.getName();
// 取得文件的后缀名。
//String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();

// 以流的形式下载文件。
InputStream fis = new BufferedInputStream(new FileInputStream(file));
byte[] buffer = new byte[fis.available()];
fis.read(buffer);
fis.close();
// 清空response
response.reset();
// 设置response的Header
response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes("utf-8"),"ISO-8859-1"));
response.addHeader("Content-Length", "" + file.length());
OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
response.setContentType("application/octet-stream");
toClient.write(buffer);
toClient.flush();
toClient.close();
} catch (IOException ex) {
ex.printStackTrace();
}
return response;
}
}

<servlet>
<servlet-name>fileDownLoadServlet</servlet-name>
<servlet-class>com.future.zfs.util.FileDownLoadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>fileDownLoadServlet</servlet-name>
<url-pattern>/fileDownLoadServlet</url-pattern>
</servlet-mapping>