用java写一个jt808协议解析

JT808 是一种车载终端通信协议，下面是一个简单的 Java 实现。

import java.nio.ByteBuffer;

public class JT808Decoder {

    public static void main(String[] args) {
        byte[] data = new byte[]{
                0x7e, 0x02, 0x00, 0x23, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
                0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13,
                0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x3b, 0x7e
        };
        JT808Decoder decoder = new JT808Decoder();
        decoder.decode(data);
    }

    public void decode(byte[] data) {
        ByteBuffer buffer = ByteBuffer.wrap(data);
        byte start = buffer.get();
        byte msgId1 = buffer.get();
        byte msgId2 = buffer.get();
        int msgId = ((msgId1 & 0xff) << 8) | (msgId2 & 0xff);
        int msgBodyProps = buffer.getShort() & 0xffff;
        int msgBodyLength = msgBodyProps & 0x3ff;
        boolean hasSubPackage = ((msgBodyProps >> 13) & 0x1) == 1;
        int packageInfoField = ((msgBodyProps >> 10) & 0x7);
        int msgBodyStartIndex = buffer.position();
        byte[] msgBody = new byte[msgBodyLength];
        buffer.get(msgBody);
        int checkSum = buffer.get() & 0xff;
        byte end = buffer.get();
        if (end != 0x7e) {
            throw new IllegalArgumentException("Invalid message format");
        }
        System.out.println("msgId: " + msgId);
        System.out.println("msgBodyProps: " + msgBodyProps);
        System.out.println("hasSubPackage: " + hasSubPackage);
        System.out.println("packageInfoField: " + packageInfoField);
        System.out.println("msgBody: " + new String(msgBody));
        System.out.println("checkSum: " + checkSum);
    }
}

这个实现只是一个简单的示例，实际解析 JT808 协议需要更多的细节处理。