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/*
* Copyright 2012 Anton Tananaev (anton.tananaev@gmail.com)
*
* 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 org.traccar.helper;
import java.util.Formatter;
import org.jboss.netty.buffer.ChannelBuffer;
import org.traccar.protocol.IntellitracFrameDecoder;
/**
* ChannelBuffer helper methods
*/
public class ChannelBufferTools {
/**
* Find string in network buffer
*/
public static Integer find(
ChannelBuffer buf,
Integer start,
Integer finish,
String subString) {
int index = start;
boolean match;
for (; index < finish; index++) {
match = true;
for (int i = 0; i < subString.length(); i++) {
char c = (char) buf.getByte(index + i);
if (c != subString.charAt(i)) {
match = false;
break;
}
}
if (match) {
return index;
}
}
return null;
}
/**
* Convert hex to integer (length in hex digits)
*/
public static int readHexInteger(ChannelBuffer buf, int length) {
int result = 0;
for (int i = 0; i < length / 2; i++) {
int b = buf.readUnsignedByte();
result *= 10;
result += b >>> 4;
result *= 10;
result += b & 0x0f;
}
if (length % 2 == 1) {
int b = buf.getUnsignedByte(buf.readerIndex());
result *= 10;
result += b >>> 4;
}
return result;
}
/**
* Return hex string
*/
public static String readHexString(ChannelBuffer buf, int length) {
StringBuilder result = new StringBuilder();
Formatter formatter = new Formatter(result);
for (int i = 0; i < length / 2; i++) {
formatter.format("%02x", buf.readByte());
}
if (length % 2 == 1) {
int b = buf.getUnsignedByte(buf.readerIndex());
formatter.format("%01x", b >>> 4);
}
return result.toString();
}
/**
* Read BCD coded coordinate (first byte has sign bit)
*/
public static double readCoordinate(ChannelBuffer buf) {
int b1 = buf.readUnsignedByte();
int b2 = buf.readUnsignedByte();
int b3 = buf.readUnsignedByte();
int b4 = buf.readUnsignedByte();
double value = (b2 & 0xf) * 10 + (b3 >> 4);
value += (((b3 & 0xf) * 10 + (b4 >> 4)) * 10 + (b4 & 0xf)) / 1000.0;
value /= 60;
value += ((b1 >> 4 & 0x7) * 10 + (b1 & 0xf)) * 10 + (b2 >> 4);
if ((b1 & 0x80) != 0) {
value = -value;
}
return value;
}
/**
* Convert integer array to byte array
*/
public static byte[] convertArray(int[] in) {
byte[] out = new byte[in.length];
for (int i = 0; i < in.length; i++) {
out[i] = (byte) in[i];
}
return out;
}
/**
* Convert hex string to byte array
*/
public static byte[] convertHexString(String in) {
int count = in.length() / 2;
byte[] out = new byte[count];
for (int i = 0; i < count; i++) {
out[i] = Integer.valueOf(in.substring(i * 2, (i + 1) * 2), 16).byteValue();
}
return out;
}
}
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