Question

I have to read a file using servlet.here is the code iam using.but file is not reading using this code.Always printing File contains null value-----------------:

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    try {
        response.setContentType("text/html");
        String filename = "D/root.properties";
        ServletContext context = getServletContext();

        InputStream inp = context.getResourceAsStream(filename);
        if (inp != null) {
            InputStreamReader isr = new InputStreamReader(inp);
            BufferedReader reader = new BufferedReader(isr);
            PrintWriter pw = response.getWriter();

            String text = "";

            while ((text = reader.readLine()) != null) {                     
            }
        } else {
            System.out.println("File contains null value-----------------");
        }
    } catch(Exception e) {
        System.out.println("Rxpn............................................."+e);
    }
}

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

Answer 1

javadoc to the rescue :

java.net.URL getResource(java.lang.String path)
throws java.net.MalformedURLException

Returns a URL to the resource that is mapped to the given path.

The path must begin with a / and is interpreted as relative to the current context root, or relative to the /META-INF/resources directory
of a JAR file inside the web application’s /WEB-INF/lib directory.
This method will first search the document root of the web application
for the requested resource, before searching any of the JAR files
inside /WEB-INF/lib. The order in which the JAR files inside
/WEB-INF/lib are searched is undefined.

If you want to read from a resource in the web app, use a path as indicated above. If you want to read from the file system, use file IO (and the correct file name): new FileInputStream("D:/root.properties")