我不熟悉使用蓝牙。
参考StackOverflow上发现的一些讨论（我现在找不到的链接），我设法制作了一个小型PC服务器，通过蓝牙将字符串发送到Android智能手机。
问题是转移速度极慢。对于像
这样的字符串ACLineStatus：在线
它们的服务时间为6550毫秒，用于获取实时信息。
如日志所示
E /执行代码的时间：6452
D / prova：ildispositivoè：DESKTOP-U1VI1GB
D / prova：ACLineStatus：在线
如何提高传输速度？
这里有服务器代码（在PC上）
package hello;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import javax.bluetooth.*;
import javax.microedition.io.*;
/**
* Class that implements an SPP Server which accepts single line of
* message from an SPP client and sends a single line of response to the client.
*/
//start server
private void startServer() throws IOException {
//Create a UUID for SPP
UUID uuid = new UUID("1101", true);
//Create the servicve url
String connectionString = "btspp://localhost:" + uuid + ";name=Sample SPP Server";
//open server url
StreamConnectionNotifier streamConnNotifier = (StreamConnectionNotifier) Connector.open(connectionString);
//Wait for client connection
System.out.println("\nServer Started. Waiting for clients to connect...");
StreamConnection connection = streamConnNotifier.acceptAndOpen();
RemoteDevice dev = RemoteDevice.getRemoteDevice(connection);
System.out.println("Remote device address: " + dev.getBluetoothAddress());
System.out.println("Remote device name: " + dev.getFriendlyName(true));
//read string from spp client
/* InputStream inStream=connection.openInputStream();
BufferedReader bReader=new BufferedReader(new InputStreamReader(inStream));
String lineRead=bReader.readLine();
System.out.println(lineRead);*/
//send response to spp client
OutputStream outStream = connection.openOutputStream();
PrintWriter pWriter = new PrintWriter(new OutputStreamWriter(outStream));
pWriter.write(SingletonBatteryStatus.getInstance().getBattery() + "\n");
pWriter.flush();
pWriter.close();
streamConnNotifier.close();
}
public void run() {
//display local device address and name
LocalDevice localDevice = null;
try {
localDevice = LocalDevice.getLocalDevice();
System.out.println("Address: " + localDevice.getBluetoothAddress());
System.out.println("Name: " + localDevice.getFriendlyName());
BluetoothSPPServer bluetoothSPPServer = new BluetoothSPPServer();
bluetoothSPPServer.startServer();
} catch (BluetoothStateException e) {
System.out.println("non c'è il bluetooth");
this.interrupt();
// e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
this.interrupt();
}
}
}
这里有客户端代码（在Android上）
package com.andrea.provabluetooth;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.UUID;
public class MainActivity extends AppCompatActivity {
private static final int REQUEST_ENABLE_BT = 1;
private BluetoothAdapter btAdapter = null;
private BluetoothSocket btSocket = null;
private OutputStream outStream = null;
private TextView out;
// Well known SPP UUID
private static final UUID MY_UUID =
UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
// Insert your server's MAC address
private static String address = "3C:F8:62:50:AE:9B";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
out = (TextView) findViewById(R.id.textView);
reciveMessage();
}
private void reciveMessage(){
out.setText("Prova Bluetooth\n\n");
btAdapter = BluetoothAdapter.getDefaultAdapter();
CheckBTState();
BluetoothDevice device = btAdapter.getRemoteDevice(address);
// Two things are needed to make a connection:
// A MAC address, which we got above.
// A Service ID or UUID. In this case we are using the
// UUID for SPP.
try {
btSocket = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) {
AlertBox("1Fatal Error", "In onResume() and socket create failed: " + e.getMessage() + ".");
}
// Discovery is resource intensive. Make sure it isn't going on
// when you attempt to connect and pass your message.
btAdapter.cancelDiscovery();
// Establish the connection. This will block until it connects.
try {
btSocket.connect();
out.append("\n...Connessione stabilita e data link aperto...");
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {
AlertBox("2Fatal Error", "In onResume() and unable to close socket during connection failure" + e2.getMessage() + ".");
}
}
InputStream inStream;
try {
inStream = btSocket.getInputStream();
BufferedReader bReader = new BufferedReader(new InputStreamReader(inStream));
long startTime = System.currentTimeMillis();
String lineRead = bReader.readLine();
long stopTime = System.currentTimeMillis();
Log.e("time to execute code", stopTime - startTime + "");
Log.d("prova", "il dispositivo è: " + device.getName());
out.append("\n\n" + lineRead);
Log.d("prova", lineRead);
} catch (IOException e) {
Log.d("prova", "il dispositivo non è: " + device.getName());
//e.printStackTrace();
}
try {
btSocket.close();
} catch (IOException e2) {
AlertBox("Fatal Error", "In onPause() and failed to close socket." + e2.getMessage() + ".");
}
}
private void CheckBTState() {
// Check for Bluetooth support and then check to make sure it is turned on
// Emulator doesn't support Bluetooth and will return null
if (btAdapter == null) {
AlertBox("5Fatal Error", "Bluetooth Not supported. Aborting.");
} else {
if (btAdapter.isEnabled()) {
out.append("\n...Bluetooth is enabled...");
} else {
//Prompt user to turn on Bluetooth
Intent enableBtIntent = new Intent(btAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
}
}
public void AlertBox(String title, String message) {
new AlertDialog.Builder(this)
.setTitle(title)
.setMessage(message + " Press OK to exit.")
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface arg0, int arg1) {
finish();
}
}).show();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
另一个小问题：我没有更改UUID，但我得到了它，因为我在stackoverflow上的另一个问题上找到的代码中找到了它。我可以这样离开，还是应该改变它？如果我必须改变它，我该怎么做？
感谢您的无比耐心
答案 0 :(得分：0)
如果它可以帮助某人，就不要关闭连接：大约6秒钟即可建立连接。如果你没有关闭连接，下一篇文章是即时的。