alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Android example source code file (DatagramTest.java)

This example Android source code file (DatagramTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" TM.

Java - Android tags/keywords

android, creating, datagrampacket, datagramsocket, datagramtest, hello, inetaddress, interruptedexception, io, ioexception, largetest, net, network, override, reflector, runtimeexception, string, test, testcase

The DatagramTest.java Android example source code

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.core;

import junit.framework.TestCase;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketTimeoutException;
import android.test.suitebuilder.annotation.LargeTest;

/**
 * Implements some simple tests for datagrams. Not as excessive as the core
 * tests, but good enough for the harness.
 */
public class DatagramTest extends TestCase {

    /**
     * Helper class that listens to incoming datagrams and reflects them to the
     * sender. Incoming datagram is interpreted as a String. It is uppercased
     * before being sent back.
     */

    class Reflector extends Thread {
        // Helper class for reflecting incoming datagrams. 
        DatagramSocket socket;

        boolean alive = true;

        byte[] buffer = new byte[256];

        DatagramPacket packet;

        /**
         * Main loop. Receives datagrams and reflects them.
         */
        @Override
        public void run() {
            try {
                while (alive) {
                    try {
                        packet.setLength(buffer.length);
                        socket.receive(packet);
                        String s = stringFromPacket(packet);
                        // System.out.println(s + " (from " + packet.getAddress() + ":" + packet.getPort() + ")");

                        try {
                            Thread.sleep(100);
                        } catch (InterruptedException ex) {
                            // Ignore.
                        }

                        stringToPacket(s.toUpperCase(), packet);

                        packet.setAddress(InetAddress.getLocalHost());
                        packet.setPort(2345);

                        socket.send(packet);
                    } catch (java.io.InterruptedIOException e) {
                    }
                }
            } catch (java.io.IOException ex) {
                ex.printStackTrace();
            } finally {
                socket.close();
            }
        }

        /**
         * Creates a new Relfector object for the given local address and port.
         */
        public Reflector(int port, InetAddress address) {
            try {
                packet = new DatagramPacket(buffer, buffer.length);
                socket = new DatagramSocket(port, address);
            } catch (IOException ex) {
                throw new RuntimeException(
                        "Creating datagram reflector failed", ex);
            }
        }
    }

    /**
     * Converts a given datagram packet's contents to a String.
     */
    static String stringFromPacket(DatagramPacket packet) {
        return new String(packet.getData(), 0, packet.getLength());
    }

    /**
     * Converts a given String into a datagram packet.
     */
    static void stringToPacket(String s, DatagramPacket packet) {
        byte[] bytes = s.getBytes();
        System.arraycopy(bytes, 0, packet.getData(), 0, bytes.length);
        packet.setLength(bytes.length);
    }

    /**
     * Implements the main part of the Datagram test.
     */
    @LargeTest
    public void testDatagram() throws Exception {

        Reflector reflector = null;
        DatagramSocket socket = null;

        try {
            // Setup the reflector, so we have a partner to send to
            reflector = new Reflector(1234, InetAddress.getLocalHost());
            reflector.start();

            byte[] buffer = new byte[256];

            DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
            socket = new DatagramSocket(2345, InetAddress.getLocalHost());

            // Send ten simple packets and check for the expected responses.
            for (int i = 1; i <= 10; i++) {
                String s = "Hello, Android world #" + i + "!";
                stringToPacket(s, packet);

                packet.setAddress(InetAddress.getLocalHost());
                packet.setPort(1234);

                socket.send(packet);

                try {
                    Thread.sleep(100);
                } catch (InterruptedException ex) {
                    // Ignore.
                }

                packet.setLength(buffer.length);
                socket.receive(packet);
                String t = stringFromPacket(packet);
                // System.out.println(t + " (from " + packet.getAddress() + ":" + packet.getPort() + ")");

                assertEquals(s.toUpperCase(), t);
            }
        } finally {
            if (reflector != null) {
                reflector.alive = false;
            }

            if (socket != null) {
                socket.close();
            }
        }
    }

    // Regression test for issue 1018003: DatagramSocket ignored a set timeout.
    @LargeTest
    public void testDatagramSocketSetSOTimeout() throws Exception {
        DatagramSocket sock = null;
        int timeout = 5000;
        long start = System.currentTimeMillis();
        try {
            sock = new DatagramSocket();
            DatagramPacket pack = new DatagramPacket(new byte[100], 100);
            sock.setSoTimeout(timeout);
            sock.receive(pack);
        } catch (SocketTimeoutException e) {
            // expected
            long delay = System.currentTimeMillis() - start;
            if (Math.abs(delay - timeout) > 1000) {
                fail("timeout was not accurate. expected: " + timeout
                        + " actual: " + delay + " miliseconds.");
            }
        } finally {
            if (sock != null) {
                sock.close();
            }
        }
    }
}

Other Android examples (source code examples)

Here is a short list of links related to this Android DatagramTest.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.