您所在位置：主题：jsp用流实现下载功能的问题
cb54927487
[专家分：40] 发布于 2007-11-12 12:43:00
各位帮帮忙：
我在做jsp的下载功能时遇到了问题，不知道什么原因：
首先我做了一个jsp文件：filedown.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>你好</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<a href="DownloadServlet">download</a>
</body>
</html>
然后我做了一个servlet：DownloadServlet.java
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class DownloadServlet extends HttpServlet {
/**
* The doGet method of the servlet.
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String filePath ="D:/apple/2007.doc";
String fileType ="doc";
File file = new File(filePath);
response.setCharacterEncoding("gb2312");
response.setContentType(fileType);
response.setHeader("Content-Disposition", "attachment; filename=" + new String(file.getName().getBytes("gb2312"),"iso8859-1"));
System.out.println(new String(file.getName().getBytes("gb2312"),"gb2312"));
OutputStream output = null;
FileInputStream fis = null;
try
{
output = response.getOutputStream();
fis = new FileInputStream(file);
byte[] b = new byte[1024];
int i = 0;
System.out.println("++++++++++++++++++++++++++++");
while((i = fis.read(b))!=-1)
{
output.write(b, 0, i);
}
output.write(b, 0, b.length);
System.out.println("++++++++++++++++++++++++++++");
output.flush();
response.flushBuffer();
}
catch(Exception e)
{
System.out.println("Error!");
e.printStackTrace();
}
finally
{
if(fis != null)
{
fis.close();
fis = null;
}
if(output != null)
{
output.close();
output = null;
}
}
}
/**
* The doPost method of the servlet.
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}
上面的servlet是我在网上找到的源代码，我加了output.write(b, 0, b.length);这句话。（可是我加没加效果都一样，都是错的）
我的准备工作是：D:/apple/2007.doc这个文件是肯定存在的。
可是我遇到的问题是：当我点击download超链接时它能转到DownloadServlet并且能显示我要下载的文件，可是当我保存在一个文件夹的时候却保存不下来，找不到保存的文件，这是什么原因呢？
很急，在线等
我在做jsp的下载功能时遇到了问题，不知道什么原因：
首先我做了一个jsp文件：filedown.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>你好</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<a href="DownloadServlet">download</a>
</body>
</html>
然后我做了一个servlet：DownloadServlet.java
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class DownloadServlet extends HttpServlet {
/**
* The doGet method of the servlet.
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String filePath ="D:/apple/2007.doc";
String fileType ="doc";
File file = new File(filePath);
response.setCharacterEncoding("gb2312");
response.setContentType(fileType);
response.setHeader("Content-Disposition", "attachment; filename=" + new String(file.getName().getBytes("gb2312"),"iso8859-1"));
System.out.println(new String(file.getName().getBytes("gb2312"),"gb2312"));
OutputStream output = null;
FileInputStream fis = null;
try
{
output = response.getOutputStream();
fis = new FileInputStream(file);
byte[] b = new byte[1024];
int i = 0;
System.out.println("++++++++++++++++++++++++++++");
while((i = fis.read(b))!=-1)
{
output.write(b, 0, i);
}
output.write(b, 0, b.length);
System.out.println("++++++++++++++++++++++++++++");
output.flush();
response.flushBuffer();
}
catch(Exception e)
{
System.out.println("Error!");
e.printStackTrace();
}
finally
{
if(fis != null)
{
fis.close();
fis = null;
}
if(output != null)
{
output.close();
output = null;
}
}
}
/**
* The doPost method of the servlet.
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}
上面的servlet是我在网上找到的源代码，我加了output.write(b, 0, b.length);这句话。（可是我加没加效果都一样，都是错的）
我的准备工作是：D:/apple/2007.doc这个文件是肯定存在的。
可是我遇到的问题是：当我点击download超链接时它能转到DownloadServlet并且能显示我要下载的文件，可是当我保存在一个文件夹的时候却保存不下来，找不到保存的文件，这是什么原因呢？
很急，在线等