Android Open Source - android_retrieval_system Base Packet

• Back to App/server  ↑

From Project

Back to project page android_retrieval_system.

License

The source code is released under:

GNU General Public License

Java Source Code

/*
 * This file is part of Android retrieval system project.
 * //from   w ww  .j  av  a  2 s.  c om
 * Android retrieval system is free software: you can redistribute it
 * and/or modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version. 
 * 
 * Android retrieval system 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 for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Android retrieval system. If not, see <http://www.gnu.org/licenses/>.
 */

package net.deerhunter.ars.protocol.packets;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;

/**
 * Abstract class that contains useful methods to construct binary
 * representation for all packets transfered through the network.
 * 
 * @author DeerHunter (vityokkv73@gmail.com)
 */
public abstract class BasePacket {
  private String hexDoublePattern = "0000000000000000";
  private String hexFloatPattern = "00000000";

  /**
   * Method writes string to the output stream using following format:
   * <code> | stringSize | string | </code>
   * 
   * @param outStream Output stream the string will be written to
   * @param string String
   * @param charset String charset
   * @throws IOException if exception occurs in the output stream
   */
  protected void formatWriteStringToArray(ByteArrayOutputStream outStream, String string, Charset charset)
      throws IOException {
    // array that holds a binary representation of String object
    byte[] stringArray = string.getBytes(charset);    
    // write size of the string
    writeIntToArray(outStream, stringArray.length);
    // write a string as byte array 
    outStream.write(stringArray);
  }
  
  protected int calculateStringSize(String string, Charset charset){
    byte[] stringArray = string.getBytes(charset);
    return stringArray.length;
  }

  /**
   * Method writes a double value to the output stream as hex string.
   * 
   * @param outStream Output stream the string will be written to
   * @param value Value that will be written to the output stream
   * @throws IOException if exception occurs in the output stream
   */
  protected void writeDoubleHexStringToArray(ByteArrayOutputStream outStream, double value) throws IOException {
    String stringValue = Long.toHexString(Double.doubleToLongBits(value));
    String fullDoubleString = hexDoublePattern.substring(0, 16 - stringValue.length()) + stringValue;
    outStream.write(fullDoubleString.getBytes());
  }

  /**
   * Method writes a float value to the output stream as hex string.
   * 
   * @param outStream Output stream the string will be written to
   * @param value Value that will be written to the output stream
   * @throws IOException if exception occurs in the output stream
   */
  protected void writeFloatHexStringToArray(ByteArrayOutputStream outStream, float value) throws IOException {
    String stringValue = Integer.toHexString(Float.floatToIntBits(value));
    String fullFloatString = hexFloatPattern.substring(0, 8 - stringValue.length()) + stringValue;
    outStream.write(fullFloatString.getBytes());
  }
  
  /**
   * Method writes a long value to the output stream.
   * 
   * @param outStream Output stream the value will be written to
   * @param value Value that will be written to the output stream
   * @throws IOException if exception occurs in the output stream
   */
  protected void writeLongToArray(ByteArrayOutputStream outStream, long value) throws IOException {
    ByteBuffer longArray = ByteBuffer.allocate(8);
    longArray.putLong(value);
    outStream.write(longArray.array());
  }
  
  /**
   * Method writes an integer value to the output stream.
   * 
   * @param outStream Output stream the value will be written to
   * @param value Value that will be written to the output stream
   * @throws IOException if exception occurs in the output stream
   */
  protected void writeIntToArray(ByteArrayOutputStream outStream, int value) throws IOException {
    ByteBuffer intArray = ByteBuffer.allocate(4);
    intArray.putInt(value);
    outStream.write(intArray.array());
  }
}

Java Source Code List

• Back to App/server  ↑