Android - Bluetooth SPP client (speed test)

/**
    此程式碼單純用來測試速度用
    https://www.plurk.com/p/lhxlfk
*/

package org.spptest;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

public class MainActivity extends AppCompatActivity {

    final static private String SERVICE_UUID = "00001101-0000-1000-8000-00805F9B34FB";

    static private MT cmt = new MT(); //主執行緒
    static private IT cit = new IT(); //InputStream 封包計數器
    static private ST cst = new ST(); //介面更新計時器

    static private class MT extends Thread{
        public void run(){
            BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
            adapter.enable();

            try {
                while(!adapter.isEnabled()){
                    sleep(10);
                }
            } catch (InterruptedException e) {
                return;
            }

            BluetoothDevice device = null;

            //如果不知道要連線哪個裝置，可以用這段來看
            /*Set<BluetoothDevice> ls = adapter.getBondedDevices();
            for(BluetoothDevice di : ls){
                push(di.toString());
            }
            //if(true)return; //臨時中斷點
            */
            //在這裡選擇預計要連線的裝置
            device = adapter.getRemoteDevice("(MAC Address)"); //TODO 知道之後再來改

            try {
                BluetoothSocket socket = device.createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
                if(socket==null){
                    push("socket==null");
                    return;
                }
                boolean cd = false;
                while (!cd){
                    try {
                        push("connecting...");
                        socket.connect();
                        cd = true;
                    }catch (IOException e){
                        sleep(5000);
                    }
                }
                OutputStream outputStream = socket.getOutputStream();
                InputStream inputStream = socket.getInputStream();

                cit.a(inputStream);

                push("start!");

                byte d = 0;
                while (true) {
                    outputStream.write(0xFF & d++);
                }
            } catch (IOException e) {
                push(e.getMessage());
                e.printStackTrace();
            } catch (InterruptedException e){
                push(e.getMessage());
            }

        }
    }

    static private class IT extends Thread{
        private InputStream is = null;
        private Object s = new Object();

        public void a(InputStream stream){
            is = stream;
            synchronized (s){
                s.notifyAll();
            }
        }

        public void run(){
            while (true){
                if(is==null){
                    try {
                        synchronized (s) {
                            s.wait();
                        }
                    } catch (InterruptedException e) {
                        return;
                    }
                }
                try {
                    is.read();
                    bps++;
                } catch (IOException e) {
                    is=null;
                    push(e.getMessage());
                    e.printStackTrace();
                }
            }
        }
    }

    static private class ST extends Thread{
        public void run(){
            Object s = new Object();
            try {
                while (true){
                    synchronized (s){
                        s.wait(1000);
                    }
                    handler.sendEmptyMessage(-1);
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    final static private String EMPTY = new String("");

    static private void push(String m){
        for (int i=message.length-1;i>0;){
            if(message[i]==null){
                message[i] = EMPTY;
            }else {
                message[i] = message[--i];
            }
        }
        message[0]=m;
    }

    static private int bps = 0;
    static private String[] message = new String[20];
    static private boolean inited = false;

    static private TextView tv = null;

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

        tv = (TextView)findViewById(R.id.message);

        if(!inited) {
            inited = true;
            cmt.start();
            cit.start();
            cst.start();
        }

    }

    static private Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            if(msg.what==-1){
                StringBuilder sb = new StringBuilder();
                sb.append(bps*8);
                bps = 0;
                sb.append(" bps\n");
                for(String i : message){
                    sb.append(i);
                    sb.append("\n");
                }
                if(tv!=null){
                    tv.setText(sb);
                }
            }
        }
    };

}