Java 如何在struts2应用程序中下载zip文件

在struts2应用程序中启用zip文件下载时，我遇到了一个问题

这是我的jsp页面

<%@ taglib prefix="s" uri="/struts-tags"%>
<s:url id="fileDownload" namespace="/" action="Download" ></s:url>

<h4>Download file - <s:a href="%{fileDownload}">MyFile.zip</s:a>
</h4>

---

请任何人帮助我，因为我不知道如何解决这个问题，可能我正在做一些愚蠢的错误，但我不能找出它。请帮帮我。我将非常感谢你

您不能像那样在客户端文件系统中写入；在您的情况下，您的服务器在您的机器中，但不要被愚弄，它是一个服务器路径，而不是客户机路径。你需要写在回复上

您不能同时使用Struts2 result和在OutputStream中写入：当手动伪造响应时，您必须绕过框架约定，自己返回结果。这种情况下的正确结果是

操作。无
：

我很久以前就写过，解释了整件事（包括需要在同一个ZIP中处理重复的文件名）

另外，请尝试正确使用
内容长度
（让浏览器绘制一个真实的进度条）。
谢谢您的回复，但它不起作用。提到返回类型为NONE没有任何作用，现在我的文件甚至还没有下载。你也需要修改你的代码，因为在回答中，我已经链接到谢谢你，先生。在你的帮助下，我已经做到了。非常感谢您为我指路。不要关闭您将发送给客户的流。我是按照您的指示做的。这已经删除了例外，但下载的zip文件仍然被破坏。您的建议真的帮了我大忙，先生
public class DownloadAction implements Action
{
    List<String> fileList = new ArrayList<String>();
    private String OUTPUT_ZIP_FILE = "C:\\Users\\Ankush\\Desktop\\MyFile.zip";
    private String SOURCE_FOLDER ;
    private FileOutputStream fos;
    private InputStream fileInputStream;
    public FileOutputStream getFos() {
        return fos;
    }

    public void setFos(FileOutputStream fos) {
        this.fos = fos;
    }

    private ZipOutputStream zos;
    public String  execute()
    {
        Map<String, Object> session = ActionContext.getContext().getSession();

        System.out.println("DOWNLOAD ACTION path="+(session.get("BASIC_PATH").toString()+session.get("username").toString()+"\\"+session.get("course_Name").toString()));
        this.setSOURCE_FOLDER(session.get("BASIC_PATH").toString()+session.get("username").toString()+"\\"+session.get("course_Name").toString());
        System.out.println("ORIGINOL PATH="+"E:\\Z800\\WebAuthoringData\\EMMRC\\Ankush\\Raag_Durga");
        this.generateFileList(new File(this.getSOURCE_FOLDER()));
        this.zipIt(OUTPUT_ZIP_FILE);
        return SUCCESS;
    }

    public InputStream getFileInputStream() {
        return fileInputStream;
    }



    public ZipOutputStream getZos() {
        return zos;
    }

    public void setZos(ZipOutputStream zos) {
        this.zos = zos;
    }

    /**
     * Zip it
     * @param zipFile output ZIP file location
     */
    public void zipIt(String zipFile){

     byte[] buffer = new byte[1024];

     try{

        fos = new FileOutputStream(zipFile);
        zos = new ZipOutputStream(fos);

        System.out.println("Output to Zip : " + zipFile);

        for(String file : this.fileList){

            System.out.println("File Added : " + file);
            ZipEntry ze= new ZipEntry(file);
            zos.putNextEntry(ze);

            fileInputStream = 
                       new FileInputStream(SOURCE_FOLDER + File.separator + file);

            int len;
            while ((len = fileInputStream.read(buffer)) > 0) {
                zos.write(buffer, 0, len);
            }
        }
         fileInputStream.close();
        fos.flush();
        zos.flush();

        zos.closeEntry();
        //remember close it
        zos.close();
        fos.close();
        System.out.println("Done");
    }catch(IOException ex){
       ex.printStackTrace();   
    }

   }

<action name="Download" class="com.cdac.action.DownloadAction">

            <result name="error">/WEB-INF/jsps/error.jsp</result>


    <result name="success" type="stream">
      <param name="contentType">application/zip</param>
      <param name="inputName">fileInputStream</param>
      <param name="contentDisposition">attachment;filename="MyFile.zip"</param>
      <param name="bufferSize">2048</param>
    </result>
    </action>

SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
    at org.apache.catalina.connector.Response.getWriter(Response.java:626)
    at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:215)
    at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:105)
    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:182)
    at org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:123)
    at org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:80)
    at org.apache.jsp.WEB_002dINF.jsps.error_jsp._jspService(error_jsp.java:82)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:593)
    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:530)
    at org.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:166)
    at org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186)
    at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:371)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:275)
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:562)
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Nov 18, 2014 3:54:05 PM com.opensymphony.xwork2.util.logging.commons.CommonsLogger error
SEVERE: Exception occurred during processing request: java.lang.IllegalStateException: getOutputStream() has already been called for this response
org.apache.jasper.JasperException: java.lang.IllegalStateException: getOutputStream() has already been called for this response
    at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:534)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:452)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:391)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:593)
    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:530)
    at org.apache.struts2.dispatcher.ServletDispatcherResult.doExecute(ServletDispatcherResult.java:166)
    at org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186)
    at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:371)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:275)
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:562)
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalStateException: getOutputStream() has already been called for this response
    at org.apache.catalina.connector.Response.getWriter(Response.java:626)
    at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:215)
    at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:105)
    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:182)
    at org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:123)
    at org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:80)
    at org.apache.jsp.WEB_002dINF.jsps.error_jsp._jspService(error_jsp.java:82)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
    ... 32 more

Nov 18, 2014 3:54:05 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [default] in context with path [/web-authoring-tool] threw exception
java.lang.IllegalStateException
    at org.apache.catalina.connector.ResponseFacade.sendError(ResponseFacade.java:443)
    at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:914)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:574)
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)