Question

我正在通过Grails下载文件，并记录了此用户已下载此文件的事实，代码如下：

class MyController {

    private void recordTrackDownload() {
        def d = new Download(session.user, "/path/to/file")
        d.save()
    }

    def download = {
        def f = new File("/path/to/file")
        recordTrackDownload()
        response.contentType = "mime/type"
        response.outputStream << f.newInputStream()
        response.outputStream.flush()
    }
}

我看到每次点击都会出现几个下载记录。我怀疑这与Firefox记录的几个请求和我在Live HTTP Headers中看到的“Transfer-Encoding：chunked”标题有关。（这种行为在Chromium中也很明显）

我也看到终端中记录的错误，这可能是相关的，可能是Grails中的错误，或者只是一个记录和忽略的错误，但它似乎并没有阻止文件实际下载：

2010-01-14 18:46:16,623 [http-8080-4] ERROR errors.GrailsExceptionResolver  - Executing action [download] of controller [com.tunited.music.DownloadTrackController]  caused exception: ClientAbortException:  java.net.SocketException: Connection reset
org.codehaus.groovy.grails.web.servlet.mvc.exceptions.ControllerExecutionException: Executing action [download] of controller [com.tunited.music.DownloadTrackController]  caused exception: ClientAbortException:  j
ava.net.SocketException: Connection reset
        at java.lang.Thread.run(Thread.java:636)
Caused by: org.codehaus.groovy.runtime.InvokerInvocationException: ClientAbortException:  java.net.SocketException: Connection reset
        ... 1 more
Caused by: ClientAbortException:  java.net.SocketException: Connection reset
        at com.tunited.music.DownloadTrackController$_closure2.doCall(DownloadTrackController.groovy:35)
        at com.tunited.music.DownloadTrackController$_closure2.doCall(DownloadTrackController.groovy)
        ... 1 more
Caused by: java.net.SocketException: Connection reset
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:113)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
        ... 3 more
2010-01-14 18:46:17,091 [http-8080-4] ERROR view.GroovyPageView  - Error processing GroovyPageView: getOutputStream() has already been called for this response
java.lang.IllegalStateException: getOutputStream() has already been called for this response
        at home_ed_dev_nomad_tunited_grails_app_views_error_gsp.run(home_ed_dev_nomad_tunited_grails_app_views_error_gsp:19)
        at java.lang.Thread.run(Thread.java:636)
2010-01-14 18:46:17,092 [http-8080-4] ERROR errors.GrailsExceptionResolver  - getOutputStream() has already been called for this response
java.lang.IllegalStateException: getOutputStream() has already been called for this response
        at java.lang.Thread.run(Thread.java:636)
2010-01-14 18:46:17,100 [http-8080-4] ERROR view.GroovyPageView  - Error processing GroovyPageView: getOutputStream() has already been called for this response
java.lang.IllegalStateException: getOutputStream() has already been called for this response
        at home_ed_dev_nomad_tunited_grails_app_views_error_gsp.run(home_ed_dev_nomad_tunited_grails_app_views_error_gsp:19)
        at java.lang.Thread.run(Thread.java:636)
2010-01-14 18:46:17,103 [http-8080-4] ERROR [/].[grails]  - Servlet.service() for servlet grails threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
        at org.apache.catalina.connector.Response.getWriter(Response.java:610)
        at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198)
        at org.codehaus.groovy.grails.web.sitemesh.GrailsPageResponseWrapper$5.activateDestination(GrailsPageResponseWrapper.java:141)
        at org.codehaus.groovy.grails.web.sitemesh.GrailsRoutablePrintWriter.getDestination(GrailsRoutablePrintWriter.java:41)
        at org.codehaus.groovy.grails.web.sitemesh.GrailsRoutablePrintWriter.flush(GrailsRoutablePrintWriter.java:159)
        at org.codehaus.groovy.grails.web.util.GrailsPrintWriter.flush(GrailsPrintWriter.java:98)
...
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
        at java.lang.Thread.run(Thread.java:636)
2010-01-14 18:46:17,106 [http-8080-4] ERROR [/].[default]  - Servlet.service() for servlet default threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
        at org.apache.catalina.connector.Response.getWriter(Response.java:610)
        at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198)
        at org.codehaus.groovy.grails.web.sitemesh.GrailsPageResponseWrapper$5.activateDestination(GrailsPageResponseWrapper.java:141)
        at org.codehaus.groovy.grails.web.sitemesh.GrailsRoutablePrintWriter.getDestination(GrailsRoutablePrintWriter.java:41)
        at org.codehaus.groovy.grails.web.sitemesh.GrailsRoutablePrintWriter.flush(GrailsRoutablePrintWriter.java:159)
        at org.codehaus.groovy.grails.web.util.GrailsPrintWriter.flush(GrailsPrintWriter.java:98)
...
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
        at java.lang.Thread.run(Thread.java:636)

理想情况下，我的控制器代码只能执行一次，而且要下载的分块文件。我可以通过多个操作来完成此操作，第一个操作记录下载，然后重定向到下载文件的第二个操作。但是使用类似闪存范围之类的东西，将另一个重定向放在路上并且必须保护第二个URL，这似乎是一个糟糕的解决方案。似乎只有我不知道HTTP协议或Grails如何工作的东西，并且有一种简单的方法可以解决这个问题。

有什么想法吗？

Answer 1

真正简单的解决方法不是对编码进行分块。如果设置内容长度，则不应该有分块。

类似的东西：

response.contentType = "mime/type"
response.contentLength = f.length()

Answer 2

我猜你上面的错误是由用户取消下载引起的。这会导致错误，并且由于某些数据已在响应中发送，您看到的异常是来自尝试将错误消息写入响应的grails。

使用分块传输编码时Grails多个请求

2 个答案: