4

在我的 Vaadin spring boot 应用程序中，我需要将文件上传到服务器并保存在那里。

将文件本地上传到我的桌面工作正常，但我想将应用程序部署到服务器，所以我想将上传的文件保存在相对于我的应用程序基本路径的目录中。

我创建了一个名为“input_files”的文件夹作为根应用程序文件夹（applicationName -> input_files）的直接子文件夹。当一个文件被上传时，文件的内容应该被写入这个“input_files”文件夹内的一个新创建的文件中。

代码：

class FileReceiver implements Upload.Receiver, Upload.SucceededListener {
  private File file;

  public OutputStream receiveUpload(String filename, String mimeType) {
    String basePath = VaadinService.getCurrent().getBaseDirectory().getAbsolutePath();                
    FileOutputStream fileOutputStream;

    try {
      //this line would work:
      //file = new File("/Users/username/Desktop/input_files/" + filename);          

      //this line does not work:
      file = new File(basePath + "/input_files/" + filename);


      fileOutputStream = new FileOutputStream(file);
      labelFilename.setCaption(filename);
    }
    catch (final java.io.FileNotFoundException e) {
      new Notification("Could not open file", e.getMessage(), Notification.Type.ERROR_MESSAGE).show(Page.getCurrent());
      return null;
    }
    return fileOutputStream;
  }

  public void uploadSucceeded(Upload.SucceededEvent event) {

  }
};

重要的代码行是这样的：

file = new File(basePathOfApplication + "/input_files/" + filename);

这条线不起作用。文件夹内没有创建input_files文件。

********************************更新***************** *****************

屏幕上显示的错误信息：

在此处输入图像描述

控制台中的错误消息：

com.vaadin.server.UploadException: Upload failed
    at com.vaadin.server.communication.FileUploadHandler.streamToReceiver(FileUploadHandler.java:631) [vaadin-server-8.1.0.jar:8.1.0]
    at com.vaadin.server.communication.FileUploadHandler.handleFileUploadValidationAndData(FileUploadHandler.java:460) [vaadin-server-8.1.0.jar:8.1.0]
    at com.vaadin.server.communication.FileUploadHandler.doHandleSimpleMultipartFileUpload(FileUploadHandler.java:413) [vaadin-server-8.1.0.jar:8.1.0]
    at com.vaadin.server.communication.FileUploadHandler.handleRequest(FileUploadHandler.java:290) [vaadin-server-8.1.0.jar:8.1.0]
    at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1568) [vaadin-server-8.1.0.jar:8.1.0]
    at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:381) [vaadin-server-8.1.0.jar:8.1.0]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-embed-websocket-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) [spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105) [spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) [spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) [spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.10.RELEASE.jar:4.3.10.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_111]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_111]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.16.jar:8.5.16]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_111]
Caused by: com.vaadin.server.NoOutputStreamException: null
    at com.vaadin.server.communication.FileUploadHandler.streamToReceiver(FileUploadHandler.java:559) [vaadin-server-8.1.0.jar:8.1.0]
    ... 43 common frames omitted
4

3 回答 3

4

确保您的应用程序可以在目录中创建文件/private/var/...。很可能，它不能。我对 Vaadin 了解不多，但文件夹本身可能是一个“只读”/“临时”目录，用于存储应用程序所需的解压类和数据。此目录可能不用于存储任何上传内容和动态内容。

该文档指出：

返回上下文基目录。通常，应用程序以具有应用程序目录的方式部署。对于 Web 应用程序，此目录是 Web 应用程序的根目录。在某些情况下，应用程序可能没有应用程序目录（例如在战争中运行的 Web 应用程序）。

所以，它可能是 even null，这也会破坏你的代码。

恕我直言，最好使用另一个专用目录进行上传，可以通过应用程序配置指定。或者使用众所周知的位置，例如/tmp.

另外，请确保首先使用file.getParentFile().mkdirs().

于 2017-10-29T10:53:09.837 回答
2

Vaadin根据Vaadin 论坛的说法，您不应该在服务中保存文件，

您应该将文件保存在app.getContext().getBaseDirectory()

  • 注意：应用程序在哪里com.vaadin.Application

您可以检查一个Sample，它还检查属性以防它不起作用：

 // cannot access example directory, possible security issue with
// Application Server or Servlet Container
// Try to read sample directory from web.xml parameter
if (application.getProperty("sampleDirectory") != null) {
                file = new File(application.getProperty("sampleDirectory"));
                if ((file != null) && (file.canRead())
                        && (file.getAbsolutePath() != null)) {
                    // Success using property
                    return file;
                }
于 2017-10-29T13:33:34.570 回答
-2

您的文件夹没有权限，请尝试授予它完全/tmp权限 

drwxrwxrwt  15 root root 4.0K Nov  4 20:23 tmp

利用sudo chmod 777 /opt/myapp/input_files/

之后尝试执行您的代码。

注意：我使用过 /opt/ 也可以使用任何其他文件夹，但请记住授予它权限。

于 2017-11-04T14:57:51.897 回答