最近想做個小實驗,比對藍芽接收上個封包擷取資料是否與下個封包擷取的一樣, 一直有問題, 大約知道是兩個暫存的array比較判斷位置放的不對, 但一直嘗試後仍是無效,不同的資料一直跑相同的輸出,故上來發問,想問問大家的邏輯.

測資:

final static byte[] PATTERN_04a = {0x02, 0x01, 0x04, 0x03
            , 0x01, 0x00, 0x00, 0x00
            , (byte) 0x0C, 0x00, 0x00, 0x00
            , 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00
    };

    final static byte[] PATTERN_04b = {
            (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF
            , 0x02, 0x01, 0x04, 0x03
            , 0x02, 0x00, 0x00, 0x00
            , (byte) 0x14, 0x00, 0x00, 0x00
            , 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x02
    };

    final static byte[] PATTERN_04c = {
            0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00
            , (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF
            , 0x02, 0x01, 0x04, 0x03
            , 0x03, 0x00, 0x00, 0x00
            , (byte) 0x1C, 0x00, 0x00, 0x00
            , 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00
            , (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF
    };

全域變數:

    int len = 0;
    int len2 = 0;
    int len3 = 0;
    int len4 = 0;
    int dataLen = 0;
    int size = 0;
    int stickCount = 0;
    byte[] tak = new byte[24];
    byte[] check = new byte[24];
    int methodCount =0;
    ArrayList<Byte> rawDataList = new ArrayList<>();

主程式碼:

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        byte[] increaseCapacity = new byte[PATTERN_04a.length];

        System.arraycopy(PATTERN_04a, 0, increaseCapacity, 0, PATTERN_04a.length);

        Byte[] byteObjects = new Byte[increaseCapacity.length];

        int i = 0;

        for (byte b : increaseCapacity) {
            byteObjects[i++] = b;  // Autoboxing.....
        }

        byte[] increaseCapacity2 = new byte[PATTERN_04b.length];

        System.arraycopy(PATTERN_04b, 0, increaseCapacity2, 0, PATTERN_04b.length);

        Byte[] byteObjects2 = new Byte[increaseCapacity2.length];

        int y = 0;

        for (byte a : increaseCapacity2) {
            byteObjects2[y++] = a;  // Autoboxing.....
        }

        byte[] increaseCapacity3 = new byte[PATTERN_04c.length];

        System.arraycopy(PATTERN_04c, 0, increaseCapacity3, 0, PATTERN_04c.length);

        Byte[] byteObjects3 = new Byte[increaseCapacity3.length];

        int t = 0;

        for (byte c : increaseCapacity3) {
            byteObjects3[t++] = c;  // Autoboxing.....
        }

//      System.out.println("原始資料暫存器放入資料前 "+ rawDataList);
        rawDataList.addAll(Arrays.asList(byteObjects));
        rawDataList.addAll(Arrays.asList(byteObjects2));
        rawDataList.addAll(Arrays.asList(byteObjects3));

//        System.out.println("listData " + rawDataList);

        byte[] result = new byte[rawDataList.size()];
        for(int a = 0; a < rawDataList.size(); a++) {
            result[a] = rawDataList.get(a).byteValue();
        }

//        StringBuilder stringBuilder2 = new StringBuilder(result.length);
//        for (byte byteChar : result)
//            stringBuilder2.append(String.format("%02X ", byteChar));
//        System.out.println(stringBuilder2.toString());

        size = result.length;

        for (int m = 0; m < size; m++) {
            if (m + 1 < size && m + 2 < size && m + 3 < size) {
                if ((result[m] & 0xFF) == 2 && (result[m+1] & 0xFF) == 1 && (result[m+2] & 0xFF) == 4 && (result[m+3] & 0xFF) == 3) {

//                  System.out.println("跑檢查標頭判斷後原始資料暫存器資料 "+ rawDataList);
                    len = (result[m+8] & 0xFF);
                    len2 = (result[m+9] & 0xFF);
                    len3 = (result[m+10] & 0xFF);
                    len4 = (result[m+11] & 0xFF);

                    dataLen = len + len2 + len3 + len4 - 4;

                    if (m+dataLen+12 < size && m+dataLen+13 < size && m+dataLen+14 < size && m+dataLen+15 < size) {
                        if (result[m+dataLen+12] == -1 && result[m+dataLen+13] == -1 && result[m+dataLen+14] == -1 && result[m+dataLen+15] == -1)
                        {
//                          testCount++;
//                          System.out.println("擷取方法呼叫次數 " + testCount);
//                          System.out.println("跑檢查標尾判斷後原始資料暫存器資料 "+ rawDataList);
                            stickCount++;
                        }
                    }
                }
            }
        }

        if( stickCount/stickCount == 1 && stickCount > 0) {
            findHeadTail(result);
        }

    }

擷取方法:

public void findHeadTail(byte[] array) {
        int length = 0;
        int length2 = 0;
        int length3 = 0;
        int length4 = 0;
        int dataLength = 0;
        int size = array.length;

        for (int k = 0; k < size; k++) {
            if (k + 1 < size && k + 2 < size && k + 3 < size) {
                if ((array[k] & 0xFF) == 2 && (array[k+1] & 0xFF) == 1 && (array[k+2] & 0xFF) == 4 && (array[k+3] & 0xFF) == 3) {
//                        headCount++;
//                        System.out.println("headCount " + headCount);
//                        System.out.println("跑尋找標頭判斷後原始資料暫存器資料 "+ rawDataList);

                    length = (array[k+8] & 0xFF);
                    length2 = (array[k+9] & 0xFF);
                    length3 = (array[k+10] & 0xFF);
                    length4 = (array[k+11] & 0xFF);

                    dataLength = length + length2 + length3 + length4 - 4;

                    if (k+dataLength+12 < size && k+dataLength+13 < size && k+dataLength+14 < size && k+dataLength+15 < size) {
                        if (array[k+dataLength+12] == -1 && array[k+dataLength+13] == -1 && array[k+dataLength+14] == -1 && array[k+dataLength+15] == -1)
                        {
//                                System.out.println("跑尋找標尾判斷後原始資料暫存器資料 "+ rawDataList);
//                                System.out.println("正確資料暫存器擷取資料前 "+ realDataList);
//                                tailCount++;
//                                System.out.println("tailCount "+ tailCount);

                            System.arraycopy(array,k+12,tak,0,dataLength);

                            System.arraycopy(array,k+12,check,0,dataLength);

//                                System.out.println("正確資料暫存器擷取資料後 "+ realDataList);

//                                StringBuilder stringBuilder = new StringBuilder(temp.length);
//                                for (byte byteChar : temp)
//                                    stringBuilder.append(String.format("%02X ", byteChar));
//                                System.out.println(stringBuilder.toString());
//                                printCount++;
//                                System.out.println("printCount "+ printCount);
                        }
                    }
                }
            }
        }

//        methodCount++;
//            System.out.println("methodCount "+ methodCount);

        StringBuilder sbTemp = new StringBuilder(tak.length);
        for (byte byteChar : tak) {
            sbTemp.append(String.format("%02X ", byteChar));
        }
        System.out.println(sbTemp.toString());

        StringBuilder sbCheck = new StringBuilder(check.length);
        for (byte byteChar : check) {
            sbCheck.append(String.format("%02X ", byteChar));
        }
        System.out.println(sbCheck.toString());

//            if(Arrays.equals(tak,check)){
//                System.out.println("資料相同 ");
//            }
//            else {
//                System.out.println("資料不相同 ");
//            }

    }

輸出: