Java tutorial
/* * Copyright 2016 - 2019 Anton Tananaev (anton@traccar.org) * * 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.protocol; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import org.traccar.BaseProtocolEncoder; import org.traccar.helper.Checksum; import org.traccar.model.Command; import java.nio.charset.StandardCharsets; public class RuptelaProtocolEncoder extends BaseProtocolEncoder { private ByteBuf encodeContent(int type, ByteBuf content) { ByteBuf buf = Unpooled.buffer(); buf.writeShort(1 + content.readableBytes()); buf.writeByte(100 + type); buf.writeBytes(content); buf.writeShort(Checksum.crc16(Checksum.CRC16_KERMIT, buf.nioBuffer(2, buf.writerIndex() - 2))); return buf; } @Override protected Object encodeCommand(Command command) { ByteBuf content = Unpooled.buffer(); switch (command.getType()) { case Command.TYPE_CUSTOM: content.writeBytes(command.getString(Command.KEY_DATA).getBytes(StandardCharsets.US_ASCII)); return encodeContent(RuptelaProtocolDecoder.MSG_SMS_VIA_GPRS, content); case Command.TYPE_REQUEST_PHOTO: content.writeByte(1); // sub-command content.writeByte(0); // source content.writeInt(0); // start timestamp content.writeInt(Integer.MAX_VALUE); // end timestamp return encodeContent(RuptelaProtocolDecoder.MSG_FILES, content); case Command.TYPE_CONFIGURATION: content.writeBytes((command.getString(Command.KEY_DATA) + "\r\n").getBytes(StandardCharsets.US_ASCII)); return encodeContent(RuptelaProtocolDecoder.MSG_DEVICE_CONFIGURATION, content); case Command.TYPE_GET_VERSION: return encodeContent(RuptelaProtocolDecoder.MSG_DEVICE_VERSION, content); case Command.TYPE_FIRMWARE_UPDATE: content.writeBytes("|FU_STRT*\r\n".getBytes(StandardCharsets.US_ASCII)); return encodeContent(RuptelaProtocolDecoder.MSG_FIRMWARE_UPDATE, content); case Command.TYPE_OUTPUT_CONTROL: content.writeInt(command.getInteger(Command.KEY_INDEX)); content.writeInt(Integer.parseInt(command.getString(Command.KEY_DATA))); return encodeContent(RuptelaProtocolDecoder.MSG_SET_IO, content); case Command.TYPE_SET_CONNECTION: String c = command.getString(Command.KEY_SERVER) + "," + command.getInteger(Command.KEY_PORT) + ",TCP"; content.writeBytes(c.getBytes(StandardCharsets.US_ASCII)); return encodeContent(RuptelaProtocolDecoder.MSG_SET_CONNECTION, content); case Command.TYPE_SET_ODOMETER: content.writeInt(Integer.parseInt(command.getString(Command.KEY_DATA))); return encodeContent(RuptelaProtocolDecoder.MSG_SET_ODOMETER, content); default: return null; } } }