[英]response.getOutputStream() throws IllegalStateException when called for the first time
I'm trying to Download a pdf from a MySQL-DB ( I get it as a Blob, and up to that point everything works just fine. But when I try to get the ServletOutputstream to send it to the client the programm crashes. 我正在尝试从MySQL-DB下载pdf(我以Blob的形式获取它,到那时为止一切正常。但是,当我尝试获取ServletOutputstream将其发送给客户端时,程序崩溃。
AFAIK the exception is thrown when the method has been called before or the getwriter-method has. AFAIK之前调用方法或getwriter方法已调用时,将引发异常。 But I don't use the getwriter-method in my code at all and the other getOutPutStream-methods in the programm are not reached (I commented them out to make sure).
但是我根本没有在代码中使用getwriter方法,并且程序中的其他getOutPutStream方法都没有达到(我将其注释掉以确保)。
(The whole thing happens in a JSP if that matters for any reason) (如果由于某种原因这很重要,那么整个事情就会在JSP中发生)
Heres my code snippet and the Exception: 这是我的代码段和异常:
Code 码
Blob pdf = null;
if(request.getParameter("reportId") != null){
pdf = testszenario.getReportErgebnisPdf(Integer.parseInt(request.getParameter("reportId")), request.getParameter("erzeugung"));
}
byte[] buf = new byte[(int)pdf.length()];
InputStream inputStream = pdf.getBinaryStream();
inputStream.read(buf);
inputStream.close();
response.setContentType("application/pdf");
response.setHeader("Content-disposition","attachment; filename=test.pdf");
ServletOutputStream sos = response.getOutputStream();
// response.getOutputStream().write(buf);
Exception 例外
26.03.2013 09:28:29 org.apache.catalina.core.ApplicationDispatcher invoke
SCHWERWIEGEND: Servlet.service() for servlet jsp threw exception
java.lang.IllegalStateException
at org.apache.jasper.runtime.ServletResponseWrapperInclude.getOutputStream(ServletResponseWrapperInclude.java:63)
at org.apache.jsp.jsp.modules.Testszenario.PostReportResultOverview_jsp._jspService(PostReportResultOverview_jsp.java:115)
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:374)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:630)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:535)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:472)
at org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:968)
at org.apache.jsp.jsp.McFrame_jsp._jspService(McFrame_jsp.java:284)
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:374)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
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:128)
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:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)
Please check if your response is committed. 请检查您的回复是否已落实。 If you try to do something on a committed response then
IllegalStateException
may arise. 如果您尝试对已提交的响应进行操作,则可能会出现
IllegalStateException
。 Response will be committed, if page buffer size is exceeded. 如果超出页面缓冲区大小,将提交响应。
It might indeed matter that you're doing this in a JSP. 在JSP中执行此操作确实很重要。 Keep in mind that the JSP is part of the output rendering phase of a web application request, so the container might have obtained the writer object already.
请记住,JSP是Web应用程序请求的输出呈现阶段的一部分,因此容器可能已经获取了writer对象。 Try moving your code into a servlet instead.
尝试将代码移入servlet。 It'll give you more control over the writer/streams.
它可以让您更好地控制编写器/流。
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