堆棧內存溢出
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使用PrintWriter和OutputStream

[英]Using PrintWriter and OutputStream

 原文  2010-01-15 11:28:16  6   4    java/ servlets/ outputstream/ printwriter

問題描述

我正在用struts創建一個項目，我在使用Jasper IReports時遇到了問題。 我想將一些信息導出到pdf文件中並且我一直得到java.lang.IllegalStateException：getOutputStream（）已被調用...由於在頁面已打開PrintWriter時在我的代碼中打開ServletOutputStream而導致異常。

代碼在模型中（因此它不在jsp中，它在java文件中），如下所示： 

    public void handle(HttpServletResponse res, Connection connection, String path)throws Exception{
    ServletOutputStream out = null;
    try {

        JasperDesign jasperDesign = JRXmlLoader.load(path);
        JasperReport jasperReport = JasperCompileManager.compileReport(jasperDesign);
        byte[] bytes = JasperRunManager.runReportToPdf(jasperReport, null, connection);
        res.setContentType("application/pdf");
        res.setContentLength(bytes.length);
        out = res.getOutputStream();
        out.write(bytes, 0, bytes.length);
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        out.flush();
        out.close();
    }

我檢查了連接，路徑和HttpServletResponse，都運行正常。

我是Jasper Reports的新手以及編寫PDF格式的東西，所以你可以 - 正確地 - 我對我在這里做的事情有一點了解，顯然我的代碼是通過網絡從某處復制/粘貼的。

我曾嘗試使用PrintWriter而不是OutputStream，將字節轉換為String並使用PrintWriter.append（String）方法（allthought不是String是CharSequence），但它不會將數據提取到PDF中。

我也嘗試獲取PrintWriter，關閉它以打開OutputStream（不起作用）或刷新它（兩者都沒有）。

任何幫助解決方案使用任何可以顯示pdf數據的解決方案都會很棒。 非常感謝！

4 個解決方案

解決方案1
 5 已采納  2010-01-15 11:49:15

查看堆棧跟蹤會很有用。

您可能首先嘗試運行健全性檢查：修改該代碼以簡單地將靜態字符串（hello world）寫入ServletOutputStream並將內容類型設置為text / html。 因為這應該工作正常： 

public void handle(HttpServletResponse res, Connection connection, String path)throws Exception{
ServletOutputStream out = null;
try {
    byte[] bytes = "hello world".getBytes();
    res.setContentType("text/html");
    res.setContentLength(bytes.length);
    out = res.getOutputStream();
    out.write(bytes, 0, bytes.length);
} catch (Exception e) {
    e.printStackTrace();
} finally {
    out.flush();
    out.close();
}

HTH

解決方案2
 3  2010-01-15 11:53:24

一些想法：

  • 如果您正在使用二進制流（PDF是二進制），PrintWriter將無法工作
  • 如果客戶端超時或斷開連接，可能會發生非法狀態。 該過程的數據包跟蹤將告訴你很多（即使你不能很好地閱讀它們）。 查看WireShark或您的平台可用的內容。 值得您花時間至少了解線路級別發生的事情。
  • 確保從報告生成中返回的數據實際上是pdf。 將其寫入文件並嘗試打開。
  • 某些情況需要您在寫入流之前設置http長度標頭，否則它們會在數據開始顯示時放棄。 這里可能有必要。

解決方案3
 1  2010-01-15 13:36:52

如何調用代碼？ 從inicio2.jsp來看，你看起來像是在JSP文件中使用scriptlet運行帶有handle方法的Java類（ inicio2.jsp是inicio2.jsp ）。 之后，Java類已將報告寫入OutputStream ，JSP文件將繼續輸出文件本身的殘余（包括空格！），這將隱式調用getWriter()將其寫入響應。 正是這樣會導致IllegalStateException因為現在你已經在Java類中調用了getOutputStream() 。

Java代碼放在Java類中是很好的，但這並不意味着您仍然可以使用JSP來調用它。 JSP不應包含任何單行Java代碼。 JSP本身就是視圖技術輸出的一部分。 要解決這個問題，只需要一個可以通過HTML <form>或<a>調用的Struts動作類（或HttpServlet ）。

解決方案4
 0  2010-01-15 12:38:00

自己的回答：

我已經在路徑中添加了一個實際連接到數據庫的jrxml，並獲得了一些真正的數據，並且它工作正常，PDF在mozilla中打開，但Exception一直在發生。 我不知道如何拋出和異常（我已調試並且異常發生在同一個地方）並且能夠看到PDF。

所以我只能繼續搜索這里實際發生的事情。 我會回答我發現的任何事情（可能在星期一）。

感謝simonlord和Jim Rush的幫助！ :)

編輯：順便說一下，這是堆棧跟蹤（它是西班牙語，如果需要我將翻譯你不理解的任何東西）：再次編輯：似乎我沒有在2010年1月15日復制'1'..可能會對1月5日發生的一絲痕跡造成混亂。 糾正。 

15-ene-2010 13:47:03 org.apache.catalina.core.ApplicationDispatcher invoke
GRAVE: El Servlet.service() para servlet jsp lanzó una excepción
java.lang.IllegalStateException: getOutputStream() ya ha sido llamado para esta respuesta
    at org.apache.catalina.connector.Response.getWriter(Response.java:607)
    at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:196)
    at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
    at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125)
    at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118)
    at org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:171)
    at org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:116)
    at org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:76)
    at org.apache.jsp.pages.inicio2_jsp._jspService(inicio2_jsp.java:300)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:679)
    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:584)
    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:497)
    at org.apache.struts.chain.commands.servlet.PerformForward.handleAsInclude(PerformForward.java:141)
    at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:92)
    at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
    at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
    at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
    at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
    at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
    at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
    at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:873)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
    at java.lang.Thread.run(Unknown Source)
15-ene-2010 13:47:03 org.apache.struts.chain.commands.AbstractExceptionHandler execute
ADVERTENCIA: Unhandled exception
org.apache.jasper.JasperException: getOutputStream() ya ha sido llamado para esta respuesta
    at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:460)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:367)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:679)
    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:584)
    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:497)
    at org.apache.struts.chain.commands.servlet.PerformForward.handleAsInclude(PerformForward.java:141)
    at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:92)
    at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
    at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
    at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
    at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
    at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
    at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
    at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:873)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
    at java.lang.Thread.run(Unknown Source)
15-ene-2010 13:47:03 org.apache.struts.chain.commands.ExceptionCatcher postprocess
ADVERTENCIA: Exception from exceptionCommand 'servlet-exception'
org.apache.jasper.JasperException: getOutputStream() ya ha sido llamado para esta respuesta
    at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:460)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:367)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:679)
    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:584)
    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:497)
    at org.apache.struts.chain.commands.servlet.PerformForward.handleAsInclude(PerformForward.java:141)
    at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:92)
    at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
    at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
    at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
    at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
    at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
    at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
    at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:873)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
    at java.lang.Thread.run(Unknown Source)
15-ene-2010 13:47:03 org.apache.catalina.core.StandardWrapperValve invoke
GRAVE: Servlet.service() para servlet action lanzó excepción
java.lang.IllegalStateException: getOutputStream() ya ha sido llamado para esta respuesta
    at org.apache.catalina.connector.Response.getWriter(Response.java:607)
    at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:196)
    at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
    at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125)
    at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118)
    at org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:171)
    at org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:116)
    at org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:76)
    at org.apache.jsp.pages.inicio2_jsp._jspService(inicio2_jsp.java:300)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:679)
    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:584)
    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:497)
    at org.apache.struts.chain.commands.servlet.PerformForward.handleAsInclude(PerformForward.java:141)
    at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:92)
    at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
    at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
    at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
    at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
    at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
    at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
    at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:873)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
    at java.lang.Thread.run(Unknown Source)

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