Android 串口通信编程及串口协议分析

/**    * 读取终端设备数据    * @author Administrator    */   private class ReadThread extends Thread {      @Override     public void run() {       super.run();        // 定义一个包的最大长度       int maxLength = 2048;       byte[] buffer = new byte[maxLength];       // 每次收到实际长度       int available = 0;       // 当前已经收到包的总长度       int currentLength = 0;       // 协议头长度4个字节（开始符1，类型1，长度2）       int headerLength = 4;        while (!isInterrupted()) {         try {           available = mInputStream.available();           if (available > 0) {             // 防止超出数组最大长度导致溢出             if (available > maxLength - currentLength) {               available = maxLength - currentLength;             }             mInputStream.read(buffer, currentLength, available);             currentLength += available;           }                    }         catch (Exception e) {           e.printStackTrace();         }          int cursor = 0;         // 如果当前收到包大于头的长度，则解析当前包         while (currentLength >= headerLength) {           // 取到头部第一个字节           if (buffer[cursor] != 0x0F) {             --currentLength;             ++cursor;             continue;           }                      int contentLenght = parseLen(buffer, cursor, headerLength);           // 如果内容包的长度大于最大内容长度或者小于等于0，则说明这个包有问题，丢弃           if (contentLenght <= 0 || contentLenght > maxLength - 5) {             currentLength = 0;             break;           }           // 如果当前获取到长度小于整个包的长度，则跳出循环等待继续接收数据           int factPackLen = contentLenght + 5;           if (currentLength < contentLenght + 5) {             break;           }            // 一个完整包即产生           // proceOnePacket(buffer,i,factPackLen);           onDataReceived(buffer, cursor, factPackLen);           currentLength -= factPackLen;           cursor += factPackLen;          }         // 残留字节移到缓冲区首         if (currentLength > 0 && cursor > 0) {           System.arraycopy(buffer, cursor, buffer, 0, currentLength);         }       }     }   }    /**    * 获取协议内容长度    * @param header    * @return    */   public int parseLen(byte buffer[], int index, int headerLength) {  //   if (buffer.length - index < headerLength) { return 0; }     byte a = buffer[index + 2];     byte b = buffer[index + 3];     int rlt = 0;     if (((a >> 7) & 0x1) == 0x1) {       rlt = (((a & 0x7f) << 8) | b);     }     else {       char[] tmp = new char[2];       tmp[0] = (char) a;       tmp[1] = (char) b;       String s = new String(tmp, 0, 2);       rlt = Integer.parseInt(s, 16);     }      return rlt;   }  protected void onDataReceived(final byte[] buffer, final int index, final int packlen) {     System.out.println("收到信息");     byte[] buf = new byte[packlen];     System.arraycopy(buffer, index, buf, 0, packlen);     ProtocolAnalyze.getInstance(myHandler).analyze(buf);    }