Android example source code file (DdmHandleHello.java)

This example Android source code file (DdmHandleHello.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, bytebuffer, chunk, chunk_feat, chunk_helo, chunk_wait, chunkhandler, ddmhandlehello, disconnected, got, io, os, runtimeexception, server, string, test, util, utilities, utils, wait

The DdmHandleHello.java Android example source code

/*
 * Copyright (C) 2007 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.ddm;

import org.apache.harmony.dalvik.ddmc.Chunk;
import org.apache.harmony.dalvik.ddmc.ChunkHandler;
import org.apache.harmony.dalvik.ddmc.DdmServer;
import android.util.Config;
import android.util.Log;
import android.os.Debug;

import java.nio.ByteBuffer;

/**
 * Handle "hello" messages and feature discovery.
 */
public class DdmHandleHello extends ChunkHandler {

    public static final int CHUNK_HELO = type("HELO");
    public static final int CHUNK_WAIT = type("WAIT");
    public static final int CHUNK_FEAT = type("FEAT");

    private static DdmHandleHello mInstance = new DdmHandleHello();


    /* singleton, do not instantiate */
    private DdmHandleHello() {}

    /**
     * Register for the messages we're interested in.
     */
    public static void register() {
        DdmServer.registerHandler(CHUNK_HELO, mInstance);
        DdmServer.registerHandler(CHUNK_FEAT, mInstance);
    }

    /**
     * Called when the DDM server connects.  The handler is allowed to
     * send messages to the server.
     */
    public void connected() {
        if (Config.LOGV)
            Log.v("ddm-hello", "Connected!");

        if (false) {
            /* test spontaneous transmission */
            byte[] data = new byte[] { 0, 1, 2, 3, 4, -4, -3, -2, -1, 127 };
            Chunk testChunk =
                new Chunk(ChunkHandler.type("TEST"), data, 1, data.length-2);
            DdmServer.sendChunk(testChunk);
        }
    }

    /**
     * Called when the DDM server disconnects.  Can be used to disable
     * periodic transmissions or clean up saved state.
     */
    public void disconnected() {
        if (Config.LOGV)
            Log.v("ddm-hello", "Disconnected!");
    }

    /**
     * Handle a chunk of data.
     */
    public Chunk handleChunk(Chunk request) {
        if (Config.LOGV)
            Log.v("ddm-heap", "Handling " + name(request.type) + " chunk");
        int type = request.type;

        if (type == CHUNK_HELO) {
            return handleHELO(request);
        } else if (type == CHUNK_FEAT) {
            return handleFEAT(request);
        } else {
            throw new RuntimeException("Unknown packet "
                + ChunkHandler.name(type));
        }
    }

    /*
     * Handle introductory packet.
     */
    private Chunk handleHELO(Chunk request) {
        if (false)
            return createFailChunk(123, "This is a test");

        /*
         * Process the request.
         */
        ByteBuffer in = wrapChunk(request);

        int serverProtoVers = in.getInt();
        if (Config.LOGV)
            Log.v("ddm-hello", "Server version is " + serverProtoVers);

        /*
         * Create a response.
         */
        String vmName = System.getProperty("java.vm.name", "?");
        String vmVersion = System.getProperty("java.vm.version", "?");
        String vmIdent = vmName + " v" + vmVersion;

        //String appName = android.app.ActivityThread.currentPackageName();
        //if (appName == null)
        //    appName = "unknown";
        String appName = DdmHandleAppName.getAppName();

        ByteBuffer out = ByteBuffer.allocate(16
                            + vmIdent.length()*2 + appName.length()*2);
        out.order(ChunkHandler.CHUNK_ORDER);
        out.putInt(DdmServer.CLIENT_PROTOCOL_VERSION);
        out.putInt(android.os.Process.myPid());
        out.putInt(vmIdent.length());
        out.putInt(appName.length());
        putString(out, vmIdent);
        putString(out, appName);

        Chunk reply = new Chunk(CHUNK_HELO, out);

        /*
         * Take the opportunity to inform DDMS if we are waiting for a
         * debugger to attach.
         */
        if (Debug.waitingForDebugger())
            sendWAIT(0);

        return reply;
    }

    /*
     * Handle request for list of supported features.
     */
    private Chunk handleFEAT(Chunk request) {
        // TODO: query the VM to ensure that support for these features
        // is actually compiled in
        final String[] features = Debug.getVmFeatureList();

        if (Config.LOGV)
            Log.v("ddm-heap", "Got feature list request");

        int size = 4 + 4 * features.length;
        for (int i = features.length-1; i >= 0; i--)
            size += features[i].length() * 2;

        ByteBuffer out = ByteBuffer.allocate(size);
        out.order(ChunkHandler.CHUNK_ORDER);
        out.putInt(features.length);
        for (int i = features.length-1; i >= 0; i--) {
            out.putInt(features[i].length());
            putString(out, features[i]);
        }

        return new Chunk(CHUNK_FEAT, out);
    }

    /**
     * Send up a WAIT chunk.  The only currently defined value for "reason"
     * is zero, which means "waiting for a debugger".
     */
    public static void sendWAIT(int reason) {
        byte[] data = new byte[] { (byte) reason };
        Chunk waitChunk = new Chunk(CHUNK_WAIT, data, 0, 1);
        DdmServer.sendChunk(waitChunk);
    }
}