java - 在与.war文件一起部署时，为什么getRealPath()返回null？

This question already has answers here:

What does servletcontext.getRealPath(“/”) mean and when should I use it

(4个答案)

2年前关闭。

getRealPath()返回本地系统中的实际路径，但与.war文件一起部署时返回null。

<%@ page import="java.io.*" %>
<%@ page contentType="text/html;charset=ISO-8859-1" %>
<%
int iLf = 10;
char cLf = (char)iLf;
String a= application.getResource("/");
//String myfile = application.getRealPath("/")+ "generate.xml";
//String myfile = request.getContextPath()+"generate.xml";
//String myfile = request.getRealPath("/")+"generate.xml";

out.println(myfile);
File outputFile = new File(myfile);
outputFile.createNewFile();
FileWriter outfile = new FileWriter(outputFile);
outfile.write(" <?xml version='1.0' encoding='UTF-8'?> "+cLf);
outfile.write(" <playlist version='1' xmlns = 'http://xspf.org/ns/0/' > " +cLf);
outfile.write(" <title>My Band Rocks Your Socks</title> "+cLf);
outfile.write("<trackList>"+cLf);
%>
 <%! String[] sports; %>
 <%
    sports = request.getParameterValues("sports");

    out.println("<html><body><h1>hello</h1></body></html>");

    if (sports != null)
    {
         for (int i = 0; i < sports.length; i++)
         {
              // outfile.writeln (sports[i]);
              String total=sports[i];
              String[] sa=total.split("[,]");
              // String[] sub=new String();
              outfile.write("<track>"+cLf);
              for (int j=0;j<sa.length;j++)
              {
                // outfile.writeln(sa[j]);
                // outfile.writeln("sa["+j+"]="+sa[j]);
                if( j == 0)
                {
                     outfile.write("<location>" + sa[0] +"</location>"+cLf);
                }
                else if (j == 1)
                     {
                        outfile.write("<image>" + sa[1] +"</image>"+cLf);
                     }
                     else if( j==2)
                          {
                            outfile.write("<title>" + sa[2] +"</title>"+cLf);
                          }

               }// end of inner for loop()
               outfile.write("</track>"+cLf);
         //outfile.writeln();
      }// end of outer for()
    }
    //else outfile.writeln ("<b>none<b>");

  outfile.write(" </trackList> "+cLf);
  outfile.write(" </playlist> "+cLf);
  outfile.close();

  %>
<object type="application/x-shockwave-flash" width="400" height="170"
          data="xspf_player.swf?playlist_url=generate.xml">
          <param name="movie" value="xspf_player.swf?playlist_url=generate.xml" />

</object>

有人可以为此提供替代方案吗？
如果您还显示了一些示例代码，那将非常有帮助。

最佳答案

首先，不建议使用ServletRequest.getRealPath(String path)。适当的替换是:

ServletContext context = session.getServletContext();
String realContextPath = context.getRealPath(request.getContextPath());

但是，ServletContext.getRealPath(String path)的API文档指出:

因此，API正在履行其契约(Contract)!但是，一切都不会丢失，因为您可以使用ServletContext中定义的以下方法从WAR加载资源:

ServletContext context = session.getServletContext();
InputStream is = context.getResourceAsStream("generate.xml");