请问：jspsmartupload 下载文件出错提示：getOutputStream() has already been called 谢谢。

Question

错误信息:
org.apache.jasper.JasperException: java.lang.IllegalStateException: getOutputStream() has already been called for this response
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:522)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:410)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause java.lang.IllegalStateException: getOutputStream() has already been called for this response
org.apache.catalina.connector.Response.getWriter(Response.java:610)
org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198)
org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125)
org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118)
org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:188)
org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:118)
org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:77)
org.apache.jsp.file_005fload_jsp._jspService(file_005fload_jsp.java:94)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

Answer 1

在Java脚本范围外（即<% ... %>之外），不要包含HTML代码、空格、回车或换行等字符，有的话将不能正确下载。不信的话，可以在上述源码中%><%之间加入一个换行符，再下载一下，保证出错。因为它影响了返回给浏览器的数据流，导致解析出错。 

Answer 2

<%// 新建一个SmartUpload对象
 SmartUpload su = new SmartUpload();
 // 初始化
 su.initialize(pageContext);
 // 设定contentDisposition为null以禁止浏览器自动打开文件，
 //保证点击链接后是下载文件。若不设定，则下载的文件扩展名为
 //doc时，浏览器将自动用word打开它。扩展名为pdf时，
 //浏览器将用acrobat打开。
 su.setContentDisposition(null);
 // 下载文件
 String file = request.getParameter("file");
 su.downloadFile(file);
 //解决 java.lang.IllegalStateException: 
 //getOutputStream() has already been called for this response
 //这个问题
 out.clear();
 out=pageContext.pushBody();  %>

Answer 3

由于jsp container在处理完成请求后会调用releasePageContet方法释放所用的PageContext object,并且同时调用
getWriter方法,由于getWriter方法与在jsp页面中使用流相关的getOutputStream方法冲突,所以会造成这种异常,解决
办法是:只需要在jsp页面的最后加上两条语句:  
out.clear();
out=pageContext.pushBody();即可(其中out,pageContext均为jsp内置对象!)

Answer 4

还是回报这个错！2011-6-19 22:22:28 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet jsp threw exception
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 org.apache.coyote.http11.InternalOutputBuffer.realWriteBytes(InternalOutputBuffer.java:760)
at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:432)
at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:347)
at org.apache.coyote.http11.InternalOutputBuffer$OutputStreamOutputBuffer.doWrite(InternalOutputBuffer.java:784)
at org.apache.coyote.http11.filters.IdentityOutputFilter.doWrite(IdentityOutputFilter.java:118)
at org.apache.coyote.http11.InternalOutputBuffer.doWrite(InternalOutputBuffer.java:593)
at org.apache.coyote.Response.doWrite(Response.java:560)
at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:353)
at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:352)
at org.apache.catalina.connector.OutputBuffer.writeBytes(OutputBuffer.java:381)
at org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:370)
at org.apache.catalina.connector.CoyoteOutputStream.write(CoyoteOutputStream.java:89)
at com.jspsmart.upload.SmartUpload.downloadFile(SmartUpload.java:579)
at com.jspsmart.upload.SmartUpload.downloadFile(SmartUpload.java:508)
at com.jspsmart.upload.SmartUpload.downloadFile(SmartUpload.java:476)
at org.apache.jsp.jsp.down_jsp._jspService(down_jsp.java:63)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)

Answer 5

这个问题我也发现了，前面的问题解决了，这个问题又冒出来。
经过试验，我发现用ie浏览器不会有这个问题，你换ie试试