Get content from url with GWT

Question

Hi, I need to get the content from url (http://myweb.com/test.php) using Google Web Toolkit (GWT) I've tried this:

GWT:

    RequestBuilder rb = new RequestBuilder(RequestBuilder.GET, 
"http://myweb.com/test.php?id=65472");
     try {
        rb.sendRequest(null, new RequestCallback() {
             public void onError(final Request request, final Throwable exception) {
                 Window.alert(exception.getMessage());
             }
             public void onResponseReceived(final Request request, final Response response) {
                 //do something
                 GWT.log("response: (" + response.getText() + ")", null);
             }
        });
     } catch (final Exception e) {
             Window.alert(e.getMessage());
     }

PHP:

<?php

$var1 = $_GET["id"];
echo "The id is: ".$var1;

?>

but it always returns empty -> response();

Answer 1

OK, solved. It does not work on "Hosted Mode", just compile, move the files to the server and it works.

Answer 2

You could use a proxy servlet in hosted mode.

If you register the supplied servlet under the correct path in web.xml, and set up the correct host/port of your PHP server in the servlet, then you can post to the development server in hosted mode.

NOTE Only POST is implemented.....

public class ProxyServlet extends HttpServlet {

    /**
     * 
     */
    private static final long serialVersionUID = 8L;

    private static final String targetServer  = "localhost";
    private static final int targetPort   = 80;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
     System.err.println("GET NOT implemented!");
     resp.sendError(HttpStatus.ORDINAL_501_Not_Implemented);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
     handleRequest(req, res);
    }

    @SuppressWarnings("unchecked")
    protected void handleRequest(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

     final StringBuffer file = new StringBuffer();

     file.append(req.getRequestURI());
     if (req.getQueryString() != null) {
      file.append("?" + req.getQueryString());
     }

     HttpURLConnection conn = (HttpURLConnection) new URL("http", targetServer, targetPort, file.toString()).openConnection();

     conn.setRequestMethod("POST");

     // copy header
     // copy headers
     Enumeration headerNames = req.getHeaderNames();
     while (headerNames.hasMoreElements()) {
      String name = (String) headerNames.nextElement();
      String value = req.getHeader(name);

      value = value.replace(":8080", ":80");

      conn.addRequestProperty(name, value);
     }

     conn.setDoOutput(true);

     try {
      OutputStream out = conn.getOutputStream();
      fastStreamcopy(req.getInputStream(), out);
     } catch (Exception e) {
      resp.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE, "Server down");
      return;
     }

     try {
      int code = conn.getResponseCode();
      String msg = conn.getResponseMessage();

      System.out.println("code: " + code + ", msg: " + msg);
      resp.setStatus(code, msg);
      Map<String, List<String>> headerFields = conn.getHeaderFields();

      for (Map.Entry<String, List<String>> e : headerFields.entrySet()) {
       for (String val : e.getValue()) {
        if (e.getKey() != null)
         resp.addHeader(e.getKey(), val);
       }
      }

      // Try normal stream, then error stream and accept if remote host says that there is no content.
      try {
       fastStreamcopy(conn.getInputStream(), resp.getOutputStream());
      } catch (IOException e) {
       try {
        fastStreamcopy(conn.getErrorStream(), resp.getOutputStream());
       } catch (Exception e1) {
        if (conn.getContentLength() == 0) {
         // That ok - nothing there
        } else {
         throw e;
        }

       }
      }
     } catch (IOException e) {
      System.err.println(e.getMessage());
      throw e;
     }

    }

    public static void fastStreamcopy(InputStream input, OutputStream output) throws IOException {
     final ReadableByteChannel inputChannel = Channels.newChannel(input);
     final WritableByteChannel outputChannel = Channels.newChannel(output);
     // copy the channels
     fastChannelCopy(inputChannel, outputChannel);
    }

    public static void fastChannelCopy(final ReadableByteChannel src, final WritableByteChannel dest) throws IOException {
     final ByteBuffer buffer = ByteBuffer.allocateDirect(16 * 1024);
     while (src.read(buffer) != -1) {
      // prepare the buffer to be drained
      buffer.flip();
      // write to the channel, may block
      dest.write(buffer);
      // If partial transfer, shift remainder down
      // If buffer is empty, same as doing clear()
      buffer.compact();
     }
     // EOF will leave buffer in fill state
     buffer.flip();
     // make sure the buffer is fully drained.
     while (buffer.hasRemaining()) {
      dest.write(buffer);
     }
    }
}