/*

 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * A simple application used by unit tests. The first argument to this

 * class is the name of a file to which a TCP port number can be written.

 *

 * By default, this class does nothing other than bind to a TCP port,

 * write the TCP port number to a file, and wait for an incoming connection

 * in order to complete the application shutdown protocol.

 */

import java.net.Socket;

import java.net.ServerSocket;

import java.io.File;

import java.io.FileOutputStream;

public class SimpleApplication {

    private static SimpleApplication myApp;      // simple app or a subclass

    private static String            myAppName;  // simple app name

    private static int               myPort;     // coordination port #

    private static ServerSocket      mySS;       // coordination socket

    // protected so a subclass can extend it; not public so creation is

    // limited.

    protected SimpleApplication() {

        // save simple app (or subclass) name for messages

        myAppName = getClass().getName();

    }

    // return the simple application (or a subclass)

    final public static SimpleApplication getMyApp() {

        return myApp;

    }

    // set the simple application (for use by a subclass)

    final public static void setMyApp(SimpleApplication _myApp) {

        myApp = _myApp;

    }

    // execute the application finish protocol

    final public void doMyAppFinish(String[] args) throws Exception {

        System.out.println("INFO: " + myAppName + " is waiting on port: " +

            myPort);

        System.out.flush();

        // wait for test harness to connect

        Socket s = mySS.accept();

        s.close();

        mySS.close();

        System.out.println("INFO: " + myAppName + " is shutting down.");

        System.out.flush();

    }

    // execute the application start protocol

    final public void doMyAppStart(String[] args) throws Exception {

        if (args.length < 1) {

            throw new RuntimeException("Usage: " + myAppName +

                " port-file [arg(s)]");

        }

        // bind to a random port

        mySS = new ServerSocket(0);

        myPort = mySS.getLocalPort();

        // Write the port number to the given file

        File f = new File(args[0]);

        FileOutputStream fos = new FileOutputStream(f);

        fos.write( Integer.toString(myPort).getBytes("UTF-8") );

        fos.close();

        System.out.println("INFO: " + myAppName + " created socket on port: " +

            myPort);

        System.out.flush();

    }

    // execute the app work (subclass can override this)

    public void doMyAppWork(String[] args) throws Exception {

    }

    public static void main(String[] args) throws Exception {

        if (myApp == null) {

            // create myApp since a subclass hasn't done so

            myApp = new SimpleApplication();

        }

        myApp.doMyAppStart(args);   // do the app start protocol

        System.out.println("INFO: " + myAppName + " is calling doMyAppWork()");

        System.out.flush();

        myApp.doMyAppWork(args);    // do the app work

        System.out.println("INFO: " + myAppName + " returned from" +

            " doMyAppWork()");

        System.out.flush();

        myApp.doMyAppFinish(args);  // do the app finish protocol

        System.exit(0);

    }

}