我知道已经有一些在SO上了，但是它们中的任何一个都无法真正解决我的问题，但是当我运行代码并开始录制音频然后按我的停止按钮时，它总是会失败，因为它在错误的状态。我不确定如何解决此问题。
这是我的MainActivity.java代码：
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.Button;
import android.widget.RadioGroup;
import android.widget.Toast;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import java.io.IOException;
import static android.Manifest.permission.RECORD_AUDIO;
import static android.Manifest.permission.WRITE_EXTERNAL_STORAGE;
public class MainActivity extends AppCompatActivity {
Button buttonStartRecording, buttonStopRecording, buttonPlayLastRecordAudio,
buttonStopPlayingRecording;
String AudioSavePathInDevice = null;
MediaRecorder mediaRecorder;
public static final int RequestPermissionCode = 1;
MediaPlayer mediaPlayer;
AudioManager audioManager;
boolean isAudioPlayInSameDevice = true;
// AudioRouter audioRouter;
RadioGroup mRadioGroup;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonStartRecording = (Button) findViewById(R.id.start_recording);
buttonStopRecording = (Button) findViewById(R.id.stop_rec);
buttonPlayLastRecordAudio = (Button) findViewById(R.id.play_last_rec);
buttonStopPlayingRecording = (Button) findViewById(R.id.stop_playing_btn);
// mRadioGroup = (RadioGroup) findViewById(R.id.radioGroup);
buttonStopRecording.setEnabled(false);
buttonPlayLastRecordAudio.setEnabled(false);
buttonStopPlayingRecording.setEnabled(false);
buttonStartRecording.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.O)
@Override
public void onClick(View view) {
// Check audio permission
if (checkPermission()) {
AudioSavePathInDevice =
Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + "AudioRecording.3gp";
// Start Media recorder
MediaRecorderReady();
try {
mediaRecorder.prepare();
mediaRecorder.start();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
buttonStartRecording.setEnabled(false);
buttonStopRecording.setEnabled(true);
Toast.makeText(MainActivity.this, "Recording started",
Toast.LENGTH_LONG).show();
} else {
requestPermission();
}
}
});
buttonStopRecording.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
buttonStopRecording.setEnabled(false);
buttonPlayLastRecordAudio.setEnabled(true);
buttonStartRecording.setEnabled(true);
buttonStopPlayingRecording.setEnabled(false);
// Stop Media recorder
mediaRecorder.stop();
Toast.makeText(MainActivity.this, "Recording Completed",
Toast.LENGTH_LONG).show();
}
});
buttonPlayLastRecordAudio.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) throws IllegalArgumentException,
SecurityException, IllegalStateException {
int selectedId = 1;
if (selectedId == 1) {
isAudioPlayInSameDevice = true;
} else {
isAudioPlayInSameDevice = false;
}
// if you want to play audio on your Mobile speaker then set isAudioPlayInSameDevice true
// and if you want to play audio to connected device then set isAudioPlayInSameDevice false.
if (isAudioPlayInSameDevice) {
audioManager.setMode(audioManager.STREAM_MUSIC);
audioManager.setSpeakerphoneOn(true);
} else {
audioManager.setSpeakerphoneOn(false);
audioManager.setMode(audioManager.MODE_NORMAL);
}
audioManager.setBluetoothScoOn(false);
audioManager.stopBluetoothSco();
buttonStopRecording.setEnabled(false);
buttonStartRecording.setEnabled(false);
buttonStopPlayingRecording.setEnabled(true);
mediaPlayer = new MediaPlayer();
try {
// Start media player
System.out.println("Recorded Audio Path-" + AudioSavePathInDevice);
mediaPlayer.setDataSource(AudioSavePathInDevice);
if (isAudioPlayInSameDevice) {
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
}
mediaPlayer.prepare();
mediaPlayer.start();
} catch (IOException e) {
e.printStackTrace();
}
Toast.makeText(MainActivity.this, "Recording Playing",
Toast.LENGTH_LONG).show();
}
});
buttonStopPlayingRecording.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
buttonStopRecording.setEnabled(false);
buttonStartRecording.setEnabled(true);
buttonStopPlayingRecording.setEnabled(false);
buttonPlayLastRecordAudio.setEnabled(true);
if (mediaPlayer != null) {
// Stop Media Player
mediaPlayer.stop();
mediaPlayer.release();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
MediaRecorderReady();
}
}
}
});
}
private BroadcastReceiver mBluetoothScoReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
int state = intent.getIntExtra(AudioManager.EXTRA_SCO_AUDIO_STATE, -1);
System.out.println("ANDROID Audio SCO state: " + state);
if (AudioManager.SCO_AUDIO_STATE_CONNECTED == state) {
/*
* Now the connection has been established to the bluetooth device.
* Record audio or whatever (on another thread).With AudioRecord you can record with an object created like this:
* new AudioRecord(MediaRecorder.AudioSource.MIC, 8000, AudioFormat.CHANNEL_CONFIGURATION_MONO,
* AudioFormat.ENCODING_PCM_16BIT, audioBufferSize);
*
* After finishing, don't forget to unregister this receiver and
* to stop the bluetooth connection with am.stopBluetoothSco();
*/
}
}
};
@RequiresApi(api = Build.VERSION_CODES.O)
public void MediaRecorderReady() {
mediaRecorder = new MediaRecorder();
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_2_TS);
mediaRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
mediaRecorder.setOutputFile(AudioSavePathInDevice);
}
@Override
protected void onResume() {
super.onResume();
IntentFilter intentFilter = new IntentFilter(AudioManager.ACTION_SCO_AUDIO_STATE_UPDATED);
registerReceiver(mBluetoothScoReceiver, intentFilter);
audioManager = (AudioManager) getApplicationContext().getSystemService(getApplicationContext().AUDIO_SERVICE);
// Start Bluetooth SCO.
audioManager.setMode(audioManager.MODE_NORMAL);
audioManager.setBluetoothScoOn(true);
audioManager.startBluetoothSco();
// Stop Speaker.
audioManager.setSpeakerphoneOn(false);
}
@Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(mBluetoothScoReceiver);
// Stop Bluetooth SCO.
audioManager.stopBluetoothSco();
audioManager.setMode(audioManager.MODE_NORMAL);
audioManager.setBluetoothScoOn(false);
// Start Speaker.
audioManager.setSpeakerphoneOn(true);
}
private void requestPermission() {
ActivityCompat.requestPermissions(MainActivity.this, new
String[]{WRITE_EXTERNAL_STORAGE, RECORD_AUDIO}, RequestPermissionCode);
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case RequestPermissionCode:
if (grantResults.length > 0) {
boolean StoragePermission = grantResults[0] ==
PackageManager.PERMISSION_GRANTED;
boolean RecordPermission = grantResults[1] ==
PackageManager.PERMISSION_GRANTED;
// if (StoragePermission && RecordPermission) {
// Toast.makeText(BluetoothAudioRecorder.this, "Permission Granted",
// Toast.LENGTH_LONG).show();
// } else {
// Toast.makeText(BluetoothAudioRecorder.this,"Permission Denied",Toast.LENGTH_LONG).show();
// }
}
break;
}
}
public boolean checkPermission() {
int result = ContextCompat.checkSelfPermission(getApplicationContext(),
WRITE_EXTERNAL_STORAGE);
int result1 = ContextCompat.checkSelfPermission(getApplicationContext(),
RECORD_AUDIO);
return result == PackageManager.PERMISSION_GRANTED &&
result1 == PackageManager.PERMISSION_GRANTED;
}
}
然后是发生错误时的日志：
2019-11-24 11:26:54.440 29627-29683/com.example.esense_application E/libc: Access denied finding property "vendor.gralloc.disable_ahardware_buffer"
2019-11-24 11:26:54.435 29627-29627/com.example.esense_application W/RenderThread: type=1400 audit(0.0:17779): avc: denied { read } for name="u:object_r:vendor_default_prop:s0" dev="tmpfs" ino=24699 scontext=u:r:untrusted_app:s0:c7,c257,c512,c768 tcontext=u:object_r:vendor_default_prop:s0 tclass=file permissive=0
2019-11-24 11:26:54.487 29627-29627/com.example.esense_application I/System.out: ANDROID Audio SCO state: 1
2019-11-24 11:26:54.487 29627-29627/com.example.esense_application I/System.out: ANDROID Audio SCO state: 2
2019-11-24 11:26:54.868 29627-29627/com.example.esense_application I/System.out: ANDROID Audio SCO state: 1
2019-11-24 11:26:57.769 29627-29627/com.example.esense_application I/System.out: ANDROID Audio SCO state: 1
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: java.io.FileNotFoundException: /storage/emulated/0/AudioRecording.3gp: open failed: EACCES (Permission denied)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at libcore.io.IoBridge.open(IoBridge.java:496)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at java.io.RandomAccessFile.<init>(RandomAccessFile.java:289)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at java.io.RandomAccessFile.<init>(RandomAccessFile.java:152)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at android.media.MediaRecorder.prepare(MediaRecorder.java:1046)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at com.example.esense_application.MainActivity$1.onClick(MainActivity.java:67)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at android.view.View.performClick(View.java:7140)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at android.view.View.performClickInternal(View.java:7117)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at android.view.View.access$3500(View.java:801)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at android.view.View$PerformClick.run(View.java:27351)
2019-11-24 11:27:00.647 29627-29627/com.example.esense_application W/System.err: at android.os.Handler.handleCallback(Handler.java:883)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at android.os.Handler.dispatchMessage(Handler.java:100)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at android.os.Looper.loop(Looper.java:214)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at android.app.ActivityThread.main(ActivityThread.java:7356)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at java.lang.reflect.Method.invoke(Native Method)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at libcore.io.Linux.open(Native Method)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at libcore.io.ForwardingOs.open(ForwardingOs.java:167)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at libcore.io.BlockGuardOs.open(BlockGuardOs.java:252)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at libcore.io.ForwardingOs.open(ForwardingOs.java:167)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at android.app.ActivityThread$AndroidOs.open(ActivityThread.java:7255)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: at libcore.io.IoBridge.open(IoBridge.java:482)
2019-11-24 11:27:00.648 29627-29627/com.example.esense_application W/System.err: ... 15 more
2019-11-24 11:27:03.528 29627-29627/com.example.esense_application E/MediaRecorder: stop called in an invalid state: 4
2019-11-24 11:27:03.528 29627-29627/com.example.esense_application D/AndroidRuntime: Shutting down VM
2019-11-24 11:27:03.529 29627-29627/com.example.esense_application E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.esense_application, PID: 29627
java.lang.IllegalStateException
at android.media.MediaRecorder.stop(Native Method)
at com.example.esense_application.MainActivity$2.onClick(MainActivity.java:98)
at android.view.View.performClick(View.java:7140)
at android.view.View.performClickInternal(View.java:7117)
at android.view.View.access$3500(View.java:801)
at android.view.View$PerformClick.run(View.java:27351)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7356)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
2019-11-24 11:27:03.540 29627-29627/com.example.esense_application I/Process: Sending signal. PID: 29627 SIG: 9
您尝试MediaRecorder时抛出stop()，因为它从未进入"recording"状态。实际上，它甚至从未进入“准备”状态，因为您对prepare()的调用未成功完成。
SOLUTION
在返回prepare()调用之前（不引发），不允许调用start（）。
在返回start()调用之前（不允许抛出），不允许调用stop（）。
请确保您为输出文件选择了有效位置。尝试使用getExternalFilesDir( null )而不是getExternalFilesDir( null )。文件路径错误是Environment.getExternalStorageDirectory()调用当前失败并显示prepare()的原因。
如您所见，吞没异常而不解决其根本原因（即仅执行EACCESS并继续进行），即使在用于学习/实验的粗糙代码中，也可能迅速导致问题。如果要添加异常处理程序，最好提供真正的错误处理-始终确保您了解为什么会引发异常。