请给出Android开发中使用camera2 Api录像并且进行保存的所有相关代码

以下是使用Camera2 API进行录像并保存的相关代码：

1. 添加权限到 AndroidManifest.xml 文件中：

<uses-feature android:name="android.hardware.camera"/>
<uses-feature android:name="android.hardware.camera.autofocus"/>
<uses-feature android:name="android.hardware.camera2.full"/>

<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

2. 在布局文件中添加一个 SurfaceView 用于预览相机：

<SurfaceView
    android:id="@+id/surface_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

3. 在 Activity 中定义相机设备和相机预览会话：

private CameraDevice mCameraDevice;
private CameraCaptureSession mPreviewSession;

4. 初始化相机设备并打开相机：

private void openCamera() {
    CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
    try {
        String cameraId = manager.getCameraIdList()[0];
        CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
        StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
        mVideoSize = chooseVideoSize(map.getOutputSizes(MediaRecorder.class));
        mPreviewSize = chooseOptimalSize(map.getOutputSizes(SurfaceTexture.class),
                mVideoSize.getWidth(), mVideoSize.getHeight());
        mMediaRecorder = new MediaRecorder();

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        manager.openCamera(cameraId, mStateCallback, null);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

private CameraDevice.StateCallback mStateCallback = new CameraDevice.StateCallback() {
    @Override
    public void onOpened(CameraDevice camera) {
        mCameraDevice = camera;
        startPreview();
    }

    @Override
    public void onDisconnected(CameraDevice camera) {
        camera.close();
        mCameraDevice = null;
    }

    @Override
    public void onError(CameraDevice camera, int error) {
        camera.close();
        mCameraDevice = null;
    }
};

5. 创建相机预览会话：

private void startPreview() {
    SurfaceTexture texture = mTextureView.getSurfaceTexture();
    texture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());
    Surface surface = new Surface(texture);

    try {
        mPreviewBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
        mPreviewBuilder.addTarget(surface);

        mCameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
            @Override
            public void onConfigured(CameraCaptureSession session) {
                mPreviewSession = session;
                updatePreview();
            }

            @Override
            public void onConfigureFailed(CameraCaptureSession session) {
                // failed
            }
        }, null);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

private void updatePreview() {
    if (null == mCameraDevice) {
        return;
    }
    mPreviewBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
    HandlerThread thread = new HandlerThread("CameraPreview");
    thread.start();
    Handler backgroundHandler = new Handler(thread.getLooper());

    try {
        mPreviewSession.setRepeatingRequest(mPreviewBuilder.build(), null, backgroundHandler);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}

6. 开始录像：

private void startRecordingVideo() {
    if (null == mCameraDevice || !mTextureView.isAvailable() || null == mPreviewSize) {
        return;
    }
    try {
        closePreviewSession();
        setUpMediaRecorder();

        SurfaceTexture texture = mTextureView.getSurfaceTexture();
        texture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());
        mPreviewBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_RECORD);
        List<Surface> surfaces = new ArrayList<>();

        Surface previewSurface = new Surface(texture);
        surfaces.add(previewSurface);
        mPreviewBuilder.addTarget(previewSurface);

        Surface recorderSurface = mMediaRecorder.getSurface();
        surfaces.add(recorderSurface);
        mPreviewBuilder.addTarget(recorderSurface);

        mCameraDevice.createCaptureSession(surfaces, new CameraCaptureSession.StateCallback() {
            @Override
            public void onConfigured(CameraCaptureSession cameraCaptureSession) {
                mPreviewSession = cameraCaptureSession;
                updatePreview();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        mIsRecordingVideo = true;
                        mMediaRecorder.start();
                    }
                });
            }

            @Override
            public void onConfigureFailed(CameraCaptureSession cameraCaptureSession) {
                // failed
            }
        }, null);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private void setUpMediaRecorder() throws IOException {
    final Activity activity = this;
    if (null == activity) {
        return;
    }
    mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
    mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
    mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
    mMediaRecorder.setOutputFile(getOutputMediaFile(MEDIA_TYPE_VIDEO).toString());
    mMediaRecorder.setVideoEncodingBitRate(10000000);
    mMediaRecorder.setVideoFrameRate(30);
    mMediaRecorder.setVideoSize(mVideoSize.getWidth(), mVideoSize.getHeight());
    mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
    mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
    int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
    switch (mSensorOrientation) {
        case SENSOR_ORIENTATION_DEFAULT_DEGREES:
            mMediaRecorder.setOrientationHint(DEFAULT_ORIENTATIONS.get(rotation));
            break;
        case SENSOR_ORIENTATION_INVERSE_DEGREES:
            mMediaRecorder.setOrientationHint(INVERSE_ORIENTATIONS.get(rotation));
            break;
    }
    mMediaRecorder.prepare();
}

private void closePreviewSession() {
    if (mPreviewSession != null) {
        mPreviewSession.close();
        mPreviewSession = null;
    }
}

private void stopRecordingVideo() {
    mIsRecordingVideo = false;
    mMediaRecorder.stop();
    mMediaRecorder.reset();
    startPreview();
}

7. 释放相机：

private void releaseCamera() {
    if (null != mCameraDevice) {
        mCameraDevice.close();
        mCameraDevice = null;
    }
}

8. 创建保存视频的文件：

private static File getOutputMediaFile(int type) {
    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES), "MyCameraApp");
    if (!mediaStorageDir.exists()) {
        if (!mediaStorageDir.mkdirs()) {
            return null;
        }
    }
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File mediaFile;
    if (type == MEDIA_TYPE_VIDEO) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator + "VID_" + timeStamp + ".mp4");
    } else {
        return null;
    }
    return mediaFile;
}

注意：需要在 Android 6.0 及以上版本动态请求相机和存储权限。