aboutsummaryrefslogtreecommitdiff
path: root/src/org/traccar/protocol/Avl301ProtocolDecoder.java
blob: 6359ba80dc0eda522c14ada0b744809e41113cac (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
/*
 * Copyright 2015 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.protocol;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.traccar.BaseProtocolDecoder;
import org.traccar.model.Event;
import org.traccar.model.Position;

import java.net.SocketAddress;
import java.util.Calendar; 
import java.util.TimeZone;

public class Avl301ProtocolDecoder extends BaseProtocolDecoder {

    public Avl301ProtocolDecoder(Avl301Protocol protocol) {
        super(protocol);
    }

    private String readImei(ChannelBuffer buf) {
        int b = buf.readUnsignedByte();
        StringBuilder imei = new StringBuilder();
        imei.append(b & 0x0F);
        for (int i = 0; i < 7; i++) {
            b = buf.readUnsignedByte();
            imei.append((b & 0xF0) >> 4);
            imei.append(b & 0x0F);
        }
        return imei.toString();
    }

    private static final int MSG_LOGIN = 'L';
    private static final int MSG_STATUS = 'H';
    private static final int MSG_GPS_LBS_STATUS = '$';

    private static void sendResponse(Channel channel, int type) {
        if (channel != null) {
            ChannelBuffer response = ChannelBuffers.directBuffer(5);
            response.writeByte('$');
            response.writeByte(type);
            response.writeByte('#');
            response.writeByte('\r'); response.writeByte('\n');
            channel.write(response);
        }
    }

    @Override
    protected Object decode(
            Channel channel, SocketAddress remoteAddress, Object msg)
            throws Exception {

        ChannelBuffer buf = (ChannelBuffer) msg;

        buf.skipBytes(1); // header
        int type = buf.readUnsignedByte();
        buf.readUnsignedByte(); // length

        if (type == MSG_LOGIN) {

            if (identify(readImei(buf), channel)) {
                sendResponse(channel, type);
            }

        } else if (hasDeviceId() && type == MSG_STATUS) {

            sendResponse(channel, type);

        } else if (hasDeviceId() && type == MSG_GPS_LBS_STATUS) {

            // Create new position
            Position position = new Position();
            position.setDeviceId(getDeviceId());
            position.setProtocol(getProtocolName());

            // Date and time(6)
            Calendar time = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
            time.clear();
            time.set(Calendar.YEAR, 2000 + buf.readUnsignedByte());
            time.set(Calendar.MONTH, buf.readUnsignedByte() - 1);
            time.set(Calendar.DAY_OF_MONTH, buf.readUnsignedByte());
            time.set(Calendar.HOUR_OF_DAY, buf.readUnsignedByte());
            time.set(Calendar.MINUTE, buf.readUnsignedByte());
            time.set(Calendar.SECOND, buf.readUnsignedByte());
            position.setTime(time.getTime());

            // GPS length and Satellites count
            int gpsLength = buf.readUnsignedByte();
            position.set(Event.KEY_SATELLITES, gpsLength & 0xf);
            gpsLength >>= 4;

            //Skip Satellite numbers
            buf.skipBytes(1);

            // Location
            double latitude = buf.readUnsignedInt() / 600000.0;
            double longitude = buf.readUnsignedInt() / 600000.0;
            position.setSpeed(buf.readUnsignedByte() * 1.0); // kph?

            // Course and flags
            int union = buf.readUnsignedShort();
            position.setCourse(union & 0x03FF);
            position.setValid((union & 0x1000) != 0);
            if ((union & 0x0400) != 0) latitude = -latitude;
            if ((union & 0x0800) != 0) longitude = -longitude;

            position.setLatitude(latitude);
            position.setLongitude(longitude);

            if ((union & 0x4000) != 0) {
                position.set("acc", (union & 0x8000) != 0);
            }

            position.set(Event.KEY_LAC, buf.readUnsignedShort());
            position.set(Event.KEY_CELL, buf.readUnsignedMedium());
            position.set(Event.KEY_ALARM, true);
            int flags = buf.readUnsignedByte();
            position.set("acc", (flags & 0x2) != 0);

            // TODO parse other flags

            position.set(Event.KEY_POWER, buf.readUnsignedByte());
            position.set(Event.KEY_GSM, buf.readUnsignedByte());
            return position;
        }

        return null;
    }

}