Question

我有一个动态Web项目有一个平面文件（或说文本文件）。我创建了一个servlet，我需要在其中使用这个文件。

我的代码如下：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

   // String resource = request.getParameter ("json") ;
             if  ( resource != null && !resource.equals ( "" )  )   {
                //use getResourceAsStream (  )  to properly get the file.
                InputStream is = getServletContext ().getResourceAsStream ("rateJSON") ;
                if  ( is != null )   {  // the resource exists
                     response.setContentType("application/json");
                     response.setHeader("Pragma", "No-cache");
                     response.setDateHeader("Expires", 0);
                     response.setHeader("Cache-Control", "no-cache");
                    StringWriter sw = new StringWriter (  ) ;
                    for  ( int c = is.read (  ) ; c != -1; c = is.read (  )  )   {
                         sw.write ( c ) ;
                     }
                    PrintWriter out = response.getWriter();
                    out.print (sw.toString ()) ;
                    out.flush();
                 }
          }

}

问题是 InputStream 具有空值。

我不确定如何获得正确的相对路径。我正在使用JBOSS作为应用服务器。

我已将资源文件添加到Dynamic Web Project的WebContent目录中。作为一个不同的approch，我尝试了这个：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub

        ServletConfig config = getServletConfig();
        String contextName = config.getInitParameter("ApplicationName");
        System.out.println("context name"+ contextName);
        String contextPath = config.getServletContext().getRealPath(contextName);
        System.out.println("context Path"+contextPath);
        //contextPath = contextPath.substring(0, contextPath.indexOf(contextName));
        contextPath += "\\rateJSON.txt";
        System.out.println(contextPath);

    String resource = request.getParameter ("json") ;
    System.out.println("Hi there1"+resource);
             if  ( resource != null && !resource.equals ( "" )  )   {
                 System.out.println("Hi there");
                //use getResourceAsStream (  )  to properly get the file.
                //InputStream is = getServletContext ().getResourceAsStream (resource) ;
                InputStream is = getServletConfig().getServletContext().getResourceAsStream(contextPath);


                if  ( is != null )   {  // the resource exists
                    System.out.println("Hi there2");
                     response.setContentType("application/json");
                     response.setHeader("Pragma", "No-cache");
                     response.setDateHeader("Expires", 0);
                     response.setHeader("Cache-Control", "no-cache");
                    StringWriter sw = new StringWriter ( );
                    for  ( int c = is.read (  ) ; c != -1; c = is.read (  )  )   {
                         sw.write ( c ) ;
                         System.out.println(c);
                     }
                    PrintWriter out = response.getWriter();
                    out.print (sw.toString ()) ;
                    System.out.println(sw.toString());
                    out.flush();
                 }
          }
  }

contextPath的值现在是：C：\ JBOSS \ jboss-5.0.1.GA \ server \ default \ tmp \ 4p72206b-uo5r7k-g0vn9pof-1-g0vsh0o9-b7 \ Nationwide.war \ WEB-INF \ rateJSON

但是在这个位置，rateJSON文件不存在？似乎JBOSS没有把这个文件放在App.war中或者没有部署它？有人可以帮助我吗？

Answer 1

首先，检查Nationwide.war以确保包含rateJSON.txt。如果是，请尝试：

String rootPath = getServletConfig().getServletContext().getRealPath("/");
File file = new File(realPath + "WEB-INF/rateJSON.txt");
InputStream is = new FileInputStream(file);

Answer 2

我认为这个（ getServletContext（）。getRealPath（））在docs ...

如果servlet容器由于任何原因（例如，当从.war存档中提供内容时）无法将虚拟路径转换为实际路径，则此方法返回null。

如何获取j2ee项目中资源的相对路径

2 个答案: