文件下载的问题，用fileupload

谢谢 leshui 的链接
里面的下载程序我试了一下没有成功。
我将下面的链接直接拖拽的网络蚂蚁里面，网络蚂蚁报错，说无效网络连接。
<a href="./fileDownload.jsp">文件下载</a>
// 一下是fileDownload.jsp文件内容<%@ page contentType="text/html; charset=gb2312" %>
<%@ page import="java.io.*" %>
<%
    String fileName = "Calculator.rar".toString();
    //读到流中
    InputStream inStream = new FileInputStream("E:/ProjectJAVA/resouce.rar");
    //设置输出的格式
    response.reset();
    response.setContentType("bin");
    response.addHeader("Content-Disposition",
                       "attachment; filename=\"" + fileName + "\"");
    //循环取出流中的数据
    byte[] b = new byte[100];
    int len;
    while((len = inStream.read(b)) >0)
    response.getOutputStream().write(b,0,len);
    inStream.close();
%>

// 上面写错了，改正
String fileName = "resouce.rar".toString();
InputStream inStream = new FileInputStream("E:/ProjectJAVA/resouce.rar");

最好是所有些非文本的流,都用servlet实现.
你蒋jsp代码移动到Servlet中应该就没有问题了.
应为在下载之前,已经向客户端发送了一些文本的内容了.
<%@ page contentType="text/html; charset=gb2312" %>
<%@ page import="java.io.*" %>
应该会出现两个空行的.用servlet就没有问题了.

我按照z3h(zhaohonghui) 说的试了
直接点击是可以下载的，但不能用网络蚂蚁下载
谁能解决用网络蚂蚁下载的问题啊？import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;
import java.io.InputStream;
import java.io.FileInputStream;public class FileDownload extends HttpServlet {    //Process the HTTP Get request
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {        String fileName = "resouce.rar";        //读到流中
        InputStream inStream = new FileInputStream("E:/ProjectJAVA/resouce.rar");        //设置输出的格式
        response.reset();
        response.setContentType("bin");
        response.addHeader("Content-Disposition",
                "attachment; filename=\"" + fileName + "\"");        //循环取出流中的数据
        byte[] b = new byte[10000];
        int len;
        while((len = inStream.read(b)) >0)
        response.getOutputStream().write(b,0,len);
        inStream.close();    }}

这里定义了最大容量
byte[] b = new byte[10000];
修改这个值就可以下载更大的文件

wujinpinga(滴水穿石)：
不是吧？我要下载六百兆的文件，岂不是要六百兆的内存？

大侠们！！！！！！救命啊！！！！！！！！！！！！！！！！！！！！！！<a href="http://localhost:7001/FileDownload?FilePath=./ziliao/&FileName=myfile.rar">下载文件</a>
直接点击链接，是可以把文件下载下来的(中文文件名也是没问题的)。可是我用网络蚂蚁下载就不行，weblogic控制台就打出错误信息
服务器是weblogic8.1，winXP(win2000上也是同样的错误)java.net.SocketException: Connection reset by peer: socket write error
        at java.net.SocketOutputStream.socketWrite0(Native Method)
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
        at weblogic.servlet.internal.ChunkUtils.writeChunkTransfer(ChunkUtils.java:250)
        at weblogic.servlet.internal.ChunkUtils.writeChunks(ChunkUtils.java:226)
        at weblogic.servlet.internal.ChunkOutput.flush(ChunkOutput.java:296)
        at weblogic.servlet.internal.ChunkOutput.checkForFlush(ChunkOutput.java:371)
        at weblogic.servlet.internal.ChunkOutput.write(ChunkOutput.java:241)
        at weblogic.servlet.internal.ChunkOutputWrapper.write(ChunkOutputWrapper.java:114)
        at weblogic.servlet.internal.ServletOutputStreamImpl.write(ServletOutputStreamImpl.java:171)
        at walkfish.web.servlet.FileDownload.downloadFiles(FileDownload.java:75)
        at walkfish.web.servlet.FileDownload.doPost(FileDownload.java:25)
        at walkfish.web.servlet.FileDownload.doGet(FileDownload.java:56)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
        at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1053)
        at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:387)
        at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:305)
        at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:6310)
        at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:317)
        at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:118)
        at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3622)
        at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2569)
        at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
        at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)下面是我的下载程序(servlet)
import javax.servlet.SingleThreadModel;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.net.URLEncoder;
import java.io.FileInputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.io.File;import walkfish.web.util.ServerGlobal;public class FileDownload
    extends HttpServlet
    implements SingleThreadModel {    private static final String CONTENT_TYPE = "text/html; charset=gb2312";
    private OutputStream outputStream = null;
    private File fileLoad = null;    public void doPost(HttpServletRequest request,HttpServletResponse response) {
        download();
    }    public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        response.setContentType(CONTENT_TYPE);
        request.setCharacterEncoding("gb2312");        String strFileName = request.getParameter("FileName");
        String strFilePath = request.getParameter("FilePath");
        strFilePath = "d:/resource/" + strFilePath;        outputStream = response.getOutputStream();        response.setHeader("content-disposition",
                           "attachment; filename="
                               + URLEncoder.encode(strFileName, "UTF-8"));
        response.setContentType("application/x-tar");        try {
            fileLoad = new File(strFilePath + strFileName);
            response.setHeader("Content_Length",
                               String.valueOf(fileLoad.length()));
        }
        catch(Exception e){
            e.printStackTrace();
            return;
        }        doPost(request,response);
    }    private void download() {        byte[] bt = new byte[1024];
        FileInputStream inputStream = null;
        try {
            inputStream = new FileInputStream(fileLoad);
        }
        catch (IOException e) {
            e.printStackTrace();
            return;
        }        int iRead = 0;
        try {
            iRead = inputStream.read(bt);
            while (iRead != -1) {
                outputStream.write(bt, 0, iRead);  // 错误是从这里抛出的
                iRead = inputStream.read(bt);
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }        try {
            outputStream.close();
            inputStream.close();
        }
        catch (IOException e) {
            e.printStackTrace();
            return;
        }    }}

outputStream.write(bt, 0, iRead); // 错误是从这里抛出的
后面加一句试试
outputStream.flush();

wuyg(平平)
我试了
我在 outputStream.write(bt, 0, iRead);
这句前面加上了System.out.print(iRead + "\t");
这句后面加上了outputStream.flush();测试发现，如果没有flush()，循环能走12次
有flush()，循环只走了一次
抛出同样的异常

调试易

文件下载的问题，用fileupload

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