android编程实现电话录音的方法

<uses-permission android:name="android.permission.READ_PHONE_STATE"/><!-- 在SDCard中创建与删除文件权限 --><uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/><!-- 往SDCard写入数据权限 --><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/><uses-permission android:name="android.permission.RECORD_AUDIO"/><!-- 访问internet权限 --><uses-permission android:name="android.permission.INTERNET"/><uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>

public class PhoneListenerService extends Service {@Overridepublic void onCreate() { TelephonyManager manager =    (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE); //监听电话的状态 manager.listen(new MyListener(), PhoneStateListener.LISTEN_CALL_STATE);}private final class MyListener extends PhoneStateListener { private String num; private MediaRecorder recorder; public void onCallStateChanged(int state, String incomingNumber) { switch (state) {  case TelephonyManager.CALL_STATE_RINGING: /* 电话进来时 */  num = incomingNumber;  break;  case TelephonyManager.CALL_STATE_OFFHOOK: /* 接起电话时 */  try {   File file = new File(Environment.getExternalStorageDirectory(), num + "_" + System.currentTimeMillis() + ".3gp");   recorder = new MediaRecorder();   recorder.setAudioSource(AudioSource.MIC);//声音采集来源(话筒)   recorder.setOutputFormat(OutputFormat.THREE_GPP);//输出的格式   recorder.setAudioEncoder(AudioEncoder.AMR_NB);//音频编码方式   recorder.setOutputFile(file.getAbsolutePath());//输出方向   recorder.prepare();   recorder.start();  } catch (Exception e) {   e.printStackTrace();  }  break;  case TelephonyManager.CALL_STATE_IDLE: /* 无任何状态时 */  if (recorder != null) {   recorder.stop();   recorder.release();  }  break; } }}}