因为我正在研究 OBD 阅读器演示。通过我的应用程序，我正在尝试连接 obd 阅读器设备，并且我的应用程序安装在 Nexus 7 中。OBD 阅读器设备正在连接到谷歌播放中可用的其他应用程序，但如果我是连接我的应用程序时出现错误 java.io.IOException: bt socket closed, read return: -1 after connection established.Any suggestions... ================================================ =======
**MainActivity:-**
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;
import android.annotation.SuppressLint;
import android.app.AlertDialog;
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.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.virgosys.demo.commands.SpeedObdCommand;
import com.virgosys.demo.commands.engine.EngineRPMObdCommand;
import com.virgosys.demo.commands.fuel.FindFuelTypeObdCommand;
public class MainActivity extends Bluetooth {
@SuppressWarnings("unused")
private Button On, Off, Visible, list;
private BluetoothAdapter BA;
private Set<BluetoothDevice> pairedDevices;
@SuppressWarnings("unused")
private ListView lv;
private BluetoothDevice device;
// private UUID uuid;
// private BluetoothSocketWrapper bluetoothSocket;
private BluetoothSocket socket;
private String deviceAddress;
String RPM, Speed, FuelType;
private TextView uuidTextView, deviceTextView, showRpm, showSpeed,
showFuelType, tv_connection_e, tv_connection_f;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
showRpm = ((TextView) findViewById(R.id.show_rpm));
showSpeed = ((TextView) findViewById(R.id.txt_speed));
showFuelType = ((TextView) findViewById(R.id.txt_fueltype));
uuidTextView = ((TextView) findViewById(R.id.txt_uuid));
deviceTextView = ((TextView) findViewById(R.id.txt_device));
// tv_connection_e = ((TextView) findViewById(R.id.txt_device));
// tv_connection_f = ((TextView) findViewById(R.id.show_error));
On = (Button) findViewById(R.id.button1);
Off = (Button) findViewById(R.id.button2);
Visible = (Button) findViewById(R.id.button3);
list = (Button) findViewById(R.id.button4);
lv = (ListView) findViewById(R.id.listView1);
BA = BluetoothAdapter.getDefaultAdapter();
try {
Process process = Runtime.getRuntime().exec("logcat -d");
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
StringBuilder log = new StringBuilder();
String line = "";
while ((line = bufferedReader.readLine()) != null) {
log.append(line);
}
TextView tv_connection_e = (TextView) findViewById(R.id.show_error);
tv_connection_e.setText(log.toString());
} catch (IOException e) {
}
}
public void on(View view) {
if (!BA.isEnabled()) {
Intent turnOn = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(turnOn, 0);
Toast.makeText(getApplicationContext(), "Turned on",
Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "Already on",
Toast.LENGTH_LONG).show();
}
}
@SuppressWarnings("unchecked")
public void list(View view) {
ArrayList deviceStrs = new ArrayList();
final ArrayList devices = new ArrayList();
BluetoothAdapter btAdapter = BluetoothAdapter.getDefaultAdapter();
pairedDevices = btAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
for (BluetoothDevice device : pairedDevices) {
deviceStrs.add(device.getName() + "\n" + device.getAddress());
devices.add(device.getAddress());
}
}
// show list
final AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
ArrayAdapter adapter = new ArrayAdapter(this,
android.R.layout.select_dialog_singlechoice,
deviceStrs.toArray(new String[deviceStrs.size()]));
alertDialog.setSingleChoiceItems(adapter, -1,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
int position = ((AlertDialog) dialog).getListView()
.getCheckedItemPosition();
deviceAddress = (String) devices.get(position);
System.out.println("Device Address-->" + deviceAddress);
/*
* Intent i = new Intent(MainActivity.this,
* SecondActivity.class); i.putExtra("uuid",
* "00001101-0000-1000-8000-00805F9B34FB");
* i.putExtra("deviceAddress", deviceAddress);
* i.putExtra("RPM", RPM); i.putExtra("Speed", Speed);
* startActivity(i);
*/
try {
dothings();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// save deviceAddress
}
});
alertDialog.setTitle("Choose Bluetooth device");
alertDialog.show();
}
@SuppressLint("NewApi")
protected void dothings() throws InterruptedException {
System.out.println("Inside Do things");
System.out.println("Device address in Do things -->" + deviceAddress);
device = BA.getRemoteDevice(deviceAddress);
// UUID SERIAL_UUID = device.getUuids()[0].getUuid();
// uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
System.out.println("Device Name-->" + device.getName());
System.out.println("Device Address-->" + device.getAddress());
System.out.println("Device Bond State-->" + device.getBondState());
System.out.println("Device Type-->" + device.getType());
System.out.println("Device UUIDS-->" + device.getUuids());
ConnectThread t = new ConnectThread(device);
t.start();
showRpm.setText(RPM);
showSpeed.setText(Speed);
showFuelType.setText(FuelType);
uuidTextView.setText("00001101-0000-1000-8000-00805F9B34FB");
deviceTextView.setText(deviceAddress);
}
public void off(View view) {
BA.disable();
Toast.makeText(getApplicationContext(), "Turned off", Toast.LENGTH_LONG)
.show();
}
public void visible(View view) {
Intent getVisible = new Intent(
BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
startActivityForResult(getVisible, 0);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
private class ConnectThread extends Thread {
private final BluetoothSocket mmSocket;
private final UUID WELL_KNOWN_UUID = UUID
.fromString("00001101-0000-1000-8000-00805f9b34fb");
private Object e;
public ConnectThread(BluetoothDevice device) {
// Use a temporary object that is later assigned to mmSocket,because
// mmSocket is final
BluetoothSocket tmp = null;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
tmp = device.createRfcommSocketToServiceRecord(WELL_KNOWN_UUID);
// This is the trick
Method m = device.getClass().getMethod("createRfcommSocket",
new Class[] { int.class });
tmp = (BluetoothSocket) m.invoke(device, 1);
} catch (Exception e) {
e.printStackTrace();
}
mmSocket = tmp;
}
public void run() {
System.out.println("Trying to connect...");
// Cancel discovery because it will slow down the connection
BA.cancelDiscovery();
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
System.out.println("Connection established");
// tv_connection_e.setText(e.print.stacktrace);
ConnectedThread tc = new ConnectedThread(mmSocket);
tc.start();
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
System.out.println("Fail to connect!");
try {
mmSocket.close();
} catch (IOException closeException) {
System.out.println("Fail to close connection");
}
return;
}
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
}
}
}
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
}
System.out.println("Inside the thread");
mmInStream = tmpIn;
mmOutStream = tmpOut;
try {
EngineRPMObdCommand engineRpmCommand = new EngineRPMObdCommand();
SpeedObdCommand speedCommand = new SpeedObdCommand();
FindFuelTypeObdCommand fueltypeCommand = new FindFuelTypeObdCommand();
System.out.println("Inside the try block");
while (!Thread.currentThread().isInterrupted()) {
System.out.println("Inside while");
// TODO handle commands result
Log.d("Poonam",
"RPM: " + engineRpmCommand.getFormattedResult());
Log.d("Poonam",
"Speed: " + speedCommand.getFormattedResult());
Log.d("Poonam",
"FuelType: " + fueltypeCommand.getFormattedResult());
RPM = engineRpmCommand.getFormattedResult();
Speed = speedCommand.getFormattedResult();
FuelType = fueltypeCommand.getFormattedResult();
try {
engineRpmCommand.run(mmInStream, mmOutStream);
speedCommand.run(mmInStream, mmOutStream);
fueltypeCommand.run(mmInStream, mmOutStream);
System.out.println("Commands Processed");
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("outside try catch");
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
System.out.println("inside catch before while");
}
// Get the input and output streams, using temp objects because
// member streams are final
}
public void run() {
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes; // bytes returned from read()
// Keep listening to the InputStream until an exception occurs
while (true) {
}
}
/* Call this from the main activity to send data to the remote device */
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) {
}
}
/* Call this from the main activity to shutdown the connection */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
}
}
}
}
**Bluetooth.java**
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.util.Log;
public class Bluetooth extends Activity{
private BluetoothSocketWrapper bluetoothSocket;
private BluetoothDevice device;
private boolean secure;
private BluetoothAdapter adapter;
private List<UUID> uuidCandidates;
private int candidate;
/**
* @param device the device
* @param secure if connection should be done via a secure socket
* @param adapter the Android BT adapter
* @param uuidCandidates a list of UUIDs. if null or empty, the Serial PP id is used
* @return
*/
public void BluetoothConnector(BluetoothDevice device, boolean secure, BluetoothAdapter adapter,
List<UUID> uuidCandidates) {
this.device = device;
this.secure = secure;
this.adapter = adapter;
this.uuidCandidates = uuidCandidates;
if (this.uuidCandidates == null || this.uuidCandidates.isEmpty()) {
this.uuidCandidates = new ArrayList<UUID>();
this.uuidCandidates.add(UUID.fromString("00001101-0000-1000-8000-00805f9b34fb"));
}
}
public BluetoothSocketWrapper connect() throws IOException {
boolean success = false;
while (selectSocket()) {
adapter.cancelDiscovery();
try {
bluetoothSocket.connect();
success = true;
break;
} catch (IOException e) {
//try the fallback
try {
bluetoothSocket = new FallbackBluetoothSocket(bluetoothSocket.getUnderlyingSocket());
Thread.sleep(500);
bluetoothSocket.connect();
success = true;
break;
} catch (FallbackException e1) {
Log.w("BT", "Could not initialize FallbackBluetoothSocket classes.", e);
} catch (InterruptedException e1) {
Log.w("BT", e1.getMessage(), e1);
} catch (IOException e1) {
Log.w("BT", "Fallback failed. Cancelling.", e1);
}
}
}
if (!success) {
throw new IOException("Could not connect to device: "+ device.getAddress());
}
return bluetoothSocket;
}
private boolean selectSocket() throws IOException {
if (candidate >= uuidCandidates.size()) {
return false;
}
BluetoothSocket tmp = null;
UUID uuid = uuidCandidates.get(candidate++);
Log.i("BT", "Attempting to connect to Protocol: "+ uuid);
if (secure) {
Method m = null;
try {
m = device.getClass().getMethod("createRfcommSocket", new Class[] {int.class});
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
tmp = (BluetoothSocket) m.invoke(device, 1);
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else {
tmp = device.createInsecureRfcommSocketToServiceRecord(uuid);
}
bluetoothSocket = new NativeBluetoothSocket(tmp);
return true;
}
public static interface BluetoothSocketWrapper {
InputStream getInputStream() throws IOException;
OutputStream getOutputStream() throws IOException;
String getRemoteDeviceName();
void connect() throws IOException;
String getRemoteDeviceAddress();
void close() throws IOException;
BluetoothSocket getUnderlyingSocket();
}
public static class NativeBluetoothSocket implements BluetoothSocketWrapper {
private BluetoothSocket socket;
public NativeBluetoothSocket(BluetoothSocket tmp) {
this.socket = tmp;
}
@Override
public InputStream getInputStream() throws IOException {
return socket.getInputStream();
}
@Override
public OutputStream getOutputStream() throws IOException {
return socket.getOutputStream();
}
@Override
public String getRemoteDeviceName() {
return socket.getRemoteDevice().getName();
}
@Override
public void connect() throws IOException {
socket.connect();
}
@Override
public String getRemoteDeviceAddress() {
return socket.getRemoteDevice().getAddress();
}
@Override
public void close() throws IOException {
socket.close();
}
@Override
public BluetoothSocket getUnderlyingSocket() {
return socket;
}
}
public class FallbackBluetoothSocket extends NativeBluetoothSocket {
private BluetoothSocket fallbackSocket;
public FallbackBluetoothSocket(BluetoothSocket tmp) throws FallbackException {
super(tmp);
try
{
Class<?> clazz = tmp.getRemoteDevice().getClass();
Class<?>[] paramTypes = new Class<?>[] {Integer.TYPE};
Method m = clazz.getMethod("createRfcommSocket", paramTypes);
Object[] params = new Object[] {Integer.valueOf(1)};
fallbackSocket = (BluetoothSocket) m.invoke(tmp.getRemoteDevice(), params);
}
catch (Exception e)
{
throw new FallbackException(e);
}
}
@Override
public InputStream getInputStream() throws IOException {
return fallbackSocket.getInputStream();
}
@Override
public OutputStream getOutputStream() throws IOException {
return fallbackSocket.getOutputStream();
}
@Override
public void connect() throws IOException {
fallbackSocket.connect();
}
@Override
public void close() throws IOException {
fallbackSocket.close();
}
}
public static class FallbackException extends Exception {
/**
*
*/
private static final long serialVersionUID = 1L;
public FallbackException(Exception e) {
super(e);
}
}
}
(MainActivity.java:367)
try {
engineRpmCommand.run(mmInStream, mmOutStream);
speedCommand.run(mmInStream, mmOutStream);
fueltypeCommand.run(mmInStream, mmOutStream);
System.out.println("Commands Processed");
} catch (InterruptedException e) {
// TODO Auto-generated catch block
367--> e.printStackTrace();
}
System.out.println("outside try catch");
}
(ObdCommand.java:164)
protected void readRawData(InputStream in) throws IOException {
byte b = 0;
StringBuilder res = new StringBuilder();
// read until '>' arrives
164--> while ((char) (b = (byte) in.read()) != '>')
res.append((char) b);
最佳答案
在抛出异常时，您是否检查过您的字符串生成器/缓冲区是否包含任何内容？
我在 Nexus 7 2012 上遇到过蓝牙问题，我唯一可以建议的是你在等待数据时使用 Thread.sleep() 并使用流中的 .available() 来确保你不不要阅读更多可用的内容。
您可以在 .available() 为零且不等于上一个循环的数量时 hibernate 循环，然后假设您在数据稳定时拥有所有数据。或者，您可以简单地捕获异常并假设您已收到此时的所有数据。
关于java.io.IOException : bt socket closed, 读取返回:-1，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28672348/