android 录制短音频

有个语音聊天需求，于是写了个工具类用来录制短音频。

该类为单例模式，通过getInstance()获取到实例后调用startRecord开始录制，调用stopRecord停止录制,没有暂停功能.

getAMRFilePath获取文件路径，只会保留最后一次的录音文件，每次开始录制时都会删除上一次的录音文件。

public class AudioRecorderr {
    private boolean isRecord = false;
    private int maxDuration = 60 * 1000;//最长录制时间
    private int maxSize = 5 * 1024 * 1024;//最大录音大小限制为5M
    private MediaRecorder mMediaRecorder;

    private Context mContext;
    private final String AUDIO_AMR_FILENAME = "temp.amr";

    private AudioRecorderr(Context context) {
        mContext = context;
    }

    private static AudioRecorderr mInstance;

    /**
     * 获取实例
     * @param context
     * @return
     */
    public synchronized static AudioRecorderr getInstance(Context context) {
        if (mInstance == null)
            mInstance = new AudioRecorderr(context);
        return mInstance;
    }

    /**
     *  开始录制
     */
    public void startRecord() {
        if (!isRecord) {
            isRecord = true;
            if (mMediaRecorder == null)
                createMediaRecord();
            try {
                mMediaRecorder.prepare();
                mMediaRecorder.start();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }

    /**
     * 结束录制
     */
    public void stopRecord() {
        close();
    }

    /**
     * 获取录音文件的大小,单位为KB
     */
    public double getRecordSize() {
        File mFile = new File(getAMRFilePath());
        if (!mFile.exists())
            return -1;
        return mFile.length() / 1024;
    }

    private void createMediaRecord() {
        mMediaRecorder = new MediaRecorder();
        /*
        * 设置音频来源为麦克风
        */
        mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);

         /*
         * 设置最长录制时间
         */
        mMediaRecorder.setMaxDuration(maxDuration);

        /*
         * 设置最大录音文件大小
         */
        mMediaRecorder.setMaxFileSize(maxSize);

        /* 设置输出文件的格式：THREE_GPP/MPEG-4/RAW_AMR/Default
         * THREE_GPP(3gp格式，H263视频/ARM音频编码)、MPEG-4、RAW_AMR(只支持音频且音频编码要求为AMR_NB)
         */
        mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);

         /* 设置音频文件的编码：AAC/AMR_NB/AMR_MB/Default */
        mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
         /* 设置输出文件的路径 */
        File file = new File(getAMRFilePath());
        if (file.exists()) {
            file.delete();
        }
        mMediaRecorder.setOutputFile(getAMRFilePath());
    }

    private void close() {
        if (mMediaRecorder != null) {
            isRecord = false;
            mMediaRecorder.stop();
            mMediaRecorder.release();
            mMediaRecorder = null;
        }
    }

    /**
     * 获取AMR格式音频文件地址
     * @return
     */
    public String getAMRFilePath() {
        return mContext.getExternalCacheDir().getAbsolutePath() + "/" + AUDIO_AMR_FILENAME;
    }

}