MinecraftPingUtil.java

/*
 * Copyright 2014 jamietech. All rights reserved.
 * https://github.com/jamietech/MinecraftServerPing
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 *
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ''AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation are those of the
 * authors and contributors and should not be interpreted as representing official policies,
 * either expressed or implied, of anybody else.
 */

package co.foxdev.foxbot.utils.minecraft;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

public class MinecraftPingUtil
{

    public static byte PACKET_HANDSHAKE = 0x00, PACKET_STATUSREQUEST = 0x00,
                       PACKET_PING = 0x01;
    public static int PROTOCOL_VERSION = 4;
    public static int STATUS_HANDSHAKE = 1;

    public static void validate(final Object o, final String m)
    {
        if (o == null)
        {
            throw new RuntimeException(m);
        }
    }

    public static void io(final boolean b, final String m) throws IOException
    {
        if (b)
        {
            throw new IOException(m);
        }
    }

    /**
     * @author thinkofdeath
     * See: https://gist.github.com/thinkofdeath/e975ddee04e9c87faf22
     */
    public static int readVarInt(DataInputStream in) throws IOException
    {
        int i = 0;
        int j = 0;

        while (true)
        {
            int k = in.readByte();
            i |= (k & 0x7F) << j++ * 7;

            if (j > 5)
            {
                throw new RuntimeException("VarInt too big");
            }

            if ((k & 0x80) != 128)
            {
                break;
            }
        }

        return i;
    }

    /**
     * @throws IOException
     * @author thinkofdeath
     * See: https://gist.github.com/thinkofdeath/e975ddee04e9c87faf22
     */
    public static void writeVarInt(DataOutputStream out, int paramInt) throws IOException
    {
        while (true)
        {
            if ((paramInt & 0xFFFFFF80) == 0)
            {
                out.writeByte(paramInt);
                return;
            }

            out.writeByte(paramInt & 0x7F | 0x80);
            paramInt >>>= 7;
        }
    }

}