在下载附件时有问题，能帮我解决一下吗？（急）

Question

2.上传的文件即使下载成功，在tomcat的表面也看不到错误，但在tomcat的日志里会有这种记载2005-02-17 08:58:57 StandardWrapperValve[jsp]: Servlet.service() for servlet jsp threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.ResponseBase.getWriter(ResponseBase.java:750)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:165)
at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:166)
at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:158)
at org.apache.jasper.runtime.JspWriterImpl.flush(JspWriterImpl.java:205)
at org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:177)
at org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:198)
at org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:193)
at org.apache.jsp.dnowload$jsp._jspService(dnowload$jsp.java:116)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:107)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:201)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:381)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:473)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.wh.util.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:25)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:243)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:190)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.CertificatesValve.invoke(CertificatesValve.java:246)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2347)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:468)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:564)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
at org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:1027)
at org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1125)
at java.lang.Thread.run(Thread.java:534)
请问怎样解决这样的问题呢？

Answer 1

这是那个smartupload类，请大家帮忙看看，谢谢！！！

Answer 2

输出流在提示下载前已经传到response里了，所以在下载前response.reset()一下，应该就可以了。我原来遇到过类似问题！

Answer 3

具体怎么做呢？是在下载download.jsp页response.reset()，还是在smartupload类里？
sorry，我刚学，不太懂，以前我只是做网页，涉及这些方面的少。

Answer 4

而且response.reset()是不是只能解决第二个问题，并不能解决*.txt不能下载的问题？

Answer 5

在下载前RESPONSE有输出了（OUTPUT），这应该是不允许的吧

Answer 6

当文件太小时，*.txt文件会打开，而不是下载

Answer 7

可以通过以下代码下载
 FileInputStream input=new FileInputStream(path);
    byte[] byteS=new byte[input.available()];
    OutputStream ops = response.getOutputStream();
    input.read(byteS);

Answer 8

这是download.jsp页
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<head>
<title>download</title>
<%@ page import="com.jspsmart.upload.*"%>
<jsp:useBean id="mySmartUpload" scope="page" class="com.jspsmart.upload.SmartUpload" />
</head>
<% // Initialization
mySmartUpload.initialize(pageContext);

// Download file
//mySmartUpload.downloadFile("/upload/你好吗.zip");

// With a physical path
// mySmartUpload.downloadFile("c:\\temp\\sample.zip")

// With options
String slavename=request.getParameter("file").trim();
// With options
String BSCaption=request.getParameter("file0").trim();
String inbidID=new String(BSCaption);


 mySmartUpload.downloadFile("/qsfile/"+inbidID,"application/x-msdownload",slavename);
%>

Answer 9

下载时用到的方法,是写到类里面的,下面就是那个java类
 public void downloadField(ResultSet rs, String columnName, String contentType, String destFileName)
        throws SQLException, IOException, ServletException
    {
        if(rs == null)
            throw new IllegalArgumentException("The RecordSet cannot be null (1045).");
        if(columnName == null)
            throw new IllegalArgumentException("The columnName cannot be null (1050).");
        if(columnName.length() == 0)
            throw new IllegalArgumentException("The columnName cannot be empty (1055).");
        byte b[] = rs.getBytes(columnName);
        if(contentType == null)
            m_response.setContentType("application/x-msdownload");
        else
        if(contentType.length() == 0)
            m_response.setContentType("application/x-msdownload");
        else
            m_response.setContentType(contentType);
        m_response.setContentLength(b.length);
        if(destFileName == null)
            m_response.setHeader("Content-Disposition", "attachment;");
        else
        if(destFileName.length() == 0)
            m_response.setHeader("Content-Disposition", "attachment;");
        else
            m_response.setHeader("Content-Disposition", "attachment; filename=".concat(String.valueOf(destFileName)));
        m_response.getOutputStream().write(b, 0, b.length);
    }

Answer 10

这个就是全部的
public void downloadFile(String sourceFilePathName)
        throws SmartUploadException, IOException, ServletException
    {
        downloadFile(sourceFilePathName, null, null);
    }    public void downloadFile(String sourceFilePathName, String contentType)
        throws SmartUploadException, IOException, ServletException
    {
        downloadFile(sourceFilePathName, contentType, null);
    }    public void downloadFile(String sourceFilePathName, String contentType, String destFileName)
        throws SmartUploadException, IOException, ServletException
    {
        downloadFile(sourceFilePathName, contentType, destFileName, 65000);
    }    public void downloadFile(String sourceFilePathName, String contentType, String destFileName, int blockSize)
        throws SmartUploadException, IOException, ServletException
    {
        if(sourceFilePathName == null)
            throw new IllegalArgumentException(String.valueOf((new StringBuffer("File '")).append(sourceFilePathName).append("' not found (1040).")));
        if(sourceFilePathName.equals(""))
            throw new IllegalArgumentException(String.valueOf((new StringBuffer("File '")).append(sourceFilePathName).append("' not found (1040).")));
        if(!isVirtual(sourceFilePathName) && m_denyPhysicalPath)
            throw new SecurityException("Physical path is denied (1035).");
        if(isVirtual(sourceFilePathName))
            sourceFilePathName = m_application.getRealPath(sourceFilePathName);
        File file = new File(sourceFilePathName);
        FileInputStream fileIn = new FileInputStream(file);
        long fileLen = file.length();
        int readBytes = 0;
        int totalRead = 0;
        byte b[] = new byte[blockSize];
        if(contentType == null)
            m_response.setContentType("application/x-msdownload");
        else
        if(contentType.length() == 0)
            m_response.setContentType("application/x-msdownload");
        else
            m_response.setContentType(contentType);
        m_response.setContentLength((int)fileLen);
        m_contentDisposition = m_contentDisposition != null ? m_contentDisposition : "attachment;";
        if(destFileName == null)
            m_response.setHeader("Content-Disposition", String.valueOf((new StringBuffer(String.valueOf(m_contentDisposition))).append(" filename=").append(getFileName(sourceFilePathName))));
        else
        if(destFileName.length() == 0)
            m_response.setHeader("Content-Disposition", m_contentDisposition);
        else
            m_response.setHeader("Content-Disposition", String.valueOf((new StringBuffer(String.valueOf(m_contentDisposition))).append(" filename=").append(destFileName)));
        while((long)totalRead < fileLen) 
        {
            readBytes = fileIn.read(b, 0, blockSize);
            totalRead += readBytes;
            m_response.getOutputStream().write(b, 0, readBytes);
        }
        fileIn.close();
    }    public void downloadField(ResultSet rs, String columnName, String contentType, String destFileName)
        throws SQLException, IOException, ServletException
    {
        if(rs == null)
            throw new IllegalArgumentException("The RecordSet cannot be null (1045).");
        if(columnName == null)
            throw new IllegalArgumentException("The columnName cannot be null (1050).");
        if(columnName.length() == 0)
            throw new IllegalArgumentException("The columnName cannot be empty (1055).");
        byte b[] = rs.getBytes(columnName);
        if(contentType == null)
            m_response.setContentType("application/x-msdownload");
        else
        if(contentType.length() == 0)
            m_response.setContentType("application/x-msdownload");
        else
            m_response.setContentType(contentType);
        m_response.setContentLength(b.length);
        if(destFileName == null)
            m_response.setHeader("Content-Disposition", "attachment;");
        else
        if(destFileName.length() == 0)
            m_response.setHeader("Content-Disposition", "attachment;");
        else
            m_response.setHeader("Content-Disposition", "attachment; filename=".concat(String.valueOf(destFileName)));
        m_response.getOutputStream().write(b, 0, b.length);
    }

Answer 11

这是我写的下载文件代码，你参考吧
<%@ page contentType="text/html;charset=gb2312" errorPage="../../error.jsp"%>
<%@page import="java.io.*"%>
<%
  String filename = request.getParameter("filename");
  String sLocalFileName= request.getParameter("lfilename");
//读到流中
  InputStream inStream=new FileInputStream(filename);
 //设置输出的格式
  response.reset();
  response.setContentType("bin");
  //response.setContentType("application/x-msdownload"); //
  response.addHeader("Content-Disposition","attachment; filename=\"" + sLocalFileName + "\"");
 //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);
  }
  response.getOutputStream().flush();
  inStream.close();
%>

Answer 12

fbysss(独孤求败)：你写的这个不用引用类文件的吗？