Android 自定義相機（可外接攝像頭）

Camera##

	相信大家對相機的使用都不陌生吧，下面我給大家分享一下自定義相機

Android提供了Camera來控制拍照，步驟如下：
（1）調用Camera的open()方法打開相機。
（2）調用Camera的getParameters（）獲取拍照參數，該方法返回一個Cmera.Parameters對象。
（3）調用Camera.Parameters對象對照相的參數進行設置。
（4）調用Camera的setParameters（），並將Camera.Parameters對象作爲參數傳入，這樣就可以對拍照進行參數控制，Android2.3.3以後不用設置。
（5）調用Camerade的startPreview()的方法開始預覽取景，在之前需要調用Camera的setPreviewDisplay(SurfaceHolder holder)設置使用哪個SurfaceView來顯示取得的圖片。
（6）調用Camera的takePicture()方法進行拍照。
（7）程序結束時，要調用Camera的stopPreview()方法停止預覽，並且通過Camera.release()來釋放資源。

Camera需要賦予的權限：

<uses-permission android:name="android.permission.CAMERA" />
    <!-- 閃光燈權限 -->
    <uses-permission android:name="android.permission.FLASHLIGHT" />
    <!-- 往SDCard寫入數據權限 -->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

接下來就是自定義的代碼了：

import android.content.Context;
import android.hardware.Camera;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;

import java.io.IOException;
import java.util.List;

/**
 * Created by DELL on 2018/3/30.
 */

public class CameraPreview extends ViewGroup implements SurfaceHolder.Callback, Camera.AutoFocusCallback {
    private final String TAG = "CameraPreview";
    /**
     * 圖片的偏移
     */
    public int moveX = 0;
    public int moveY = 0;

    public SurfaceView mSurfaceView;
    private SurfaceHolder mHolder;
    public Camera.Size mPreviewSize;
    private List<Camera.Size> mSupportedPreviewSizes;

    public Camera.Size mPictureSize;
    private List<Camera.Size> mSupportedPictureSizes;

    private Camera mCamera;

    public CameraPreview(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    public CameraPreview(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context);
    }

    public SurfaceHolder getLouisSurfaceHolder() {
        return mHolder;
    }

    private void init(Context context) {
        mSurfaceView = new SurfaceView(context);
        ViewGroup.LayoutParams layoutParams = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
        addView(mSurfaceView, layoutParams);
        mHolder = mSurfaceView.getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void setCamera(Camera camera) {
        mCamera = camera;
        if (mCamera != null) {
            try {
                mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
                mSupportedPictureSizes = mCamera.getParameters().getSupportedPictureSizes();
                for (Camera.Size size : mSupportedPreviewSizes) {
                    Log.e(TAG, "CameraPreview for mPreviewSize w - h : " + size.width + " - " + size.height);
                }
                for (Camera.Size size : mSupportedPictureSizes) {
                    Log.e(TAG, "CameraPreview for mPictureSize w - h : " + size.width + " - " + size.height);
                }
                mCamera.setDisplayOrientation(90);
            } catch (Exception e) {
                e.printStackTrace();
            }
            requestLayout();
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // 我們故意忽視了孩子的測量，因爲它是一個表面視圖的包裝器，它將攝像機的預覽置於中心，而不是拉伸
        final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
        final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
        setMeasuredDimension(width, height);
        if (mSupportedPreviewSizes != null) {
            // 需要寬高切換 因爲相機有90度的角度
            mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, height, width);
        }
        if (mSupportedPictureSizes != null) {
            mPictureSize = getOptimalPreviewSize(mSupportedPictureSizes, height, width);
        }

    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        if (changed && getChildCount() > 0) {
            final View child = getChildAt(0);

            final int width = r - l;
            final int height = b - t;

            int previewWidth = width;
            int previewHeight = height;
            if (mPreviewSize != null) {
                previewWidth = mPreviewSize.height;
                previewHeight = mPreviewSize.width;
            }

            // 將子視圖置於父視圖內
            if (width * previewHeight > height * previewWidth) {

                final int scaleWidth = width;
                final int scaleHeight = width * previewHeight / previewWidth;
                moveX = 0;
                moveY = (scaleHeight - height) / 2;
                if (moveY < 0) {
                    moveY = 0;
                }
                child.layout(-moveX, -moveY, scaleWidth, scaleHeight);
            } else {

                final int scaleHeight = height;
                final int scaleWidth = height * previewWidth / previewHeight;
                moveX = (scaleWidth - width) / 2;
                moveY = 0;
                if (moveX < 0) {
                    moveX = 0;
                }
                child.layout(-moveX, -moveY, scaleWidth, scaleHeight);
            }

        }
    }

    public void surfaceCreated(SurfaceHolder holder) {
        Log.d("", "surface surfaceCreated()");
        // 表面已經被創造出來，獲得相機並告訴它在哪裏。
        try {
            if (mCamera != null) {
                mCamera.setPreviewDisplay(holder);
            }
        } catch (IOException exception) {
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // 當我們返回時，表面會被破壞，所以停止預覽。
        if (mCamera != null) {
            mCamera.stopPreview();
        }
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        if (mCamera == null) {
            return;
        }
        try {
            // 現在已知大小，設置相機參數並開始。
            // 預覽
            Camera.Parameters parameters = mCamera.getParameters();
            parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
            parameters.setPictureSize(mPictureSize.width, mPictureSize.height);
            requestLayout();

            mCamera.setParameters(parameters);
            mCamera.startPreview();
            mCamera.autoFocus(this);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onAutoFocus(boolean success, Camera camera) {

    }

    private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
        final double ASPECT_TOLERANCE = 0.1;
        double targetRatio = (double) w / h;
        if (sizes == null) return null;

        Camera.Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;

        int targetHeight = h;

        // 試着找出一個尺寸匹配的寬比和大小。
        for (Camera.Size size : sizes) {
            double ratio = (double) size.width / size.height;
            if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }
        // 找不到一個匹配的縱橫比，忽略要求。
        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Camera.Size size : sizes) {
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }
        }
        return optimalSize;
    }
}

Activity的代碼:

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.hardware.Camera;
import android.net.Uri;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.Display;
import android.view.Surface;
import android.view.View;
import android.view.WindowManager;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.Toast;

import com.example.dell.facedetection.CameraLine;
import com.example.dell.facedetection.view.CameraPreview;
import com.example.dell.facedetection.DoubleClickConfig;
import com.example.dell.facedetection.R;
import com.example.dell.facedetection.utils.ScreenSwitchUtils;
import com.example.dell.facedetection.utils.Utils;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class CameraActivity extends AppCompatActivity implements Camera.PictureCallback, Camera.ShutterCallback {

    public static final int FLAG_CHOOCE_PICTURE = 2001;
    private final int FLAG_AUTO_FOCUS = 1001;
    private final int TAKE_PHOTO_FINISH = 1002;

    private final int FOCUS_DURATION = 3000;//延遲聚焦

    private int mScreenHeight, mScreenWidth;
    private int viewHeight;

    public static final int ZOOM_FACTOR = 5;//縮放因子
    private int zoomValue = 0;
    private boolean safeToTakePicture = true;

    private CameraPreview mPreview;
    Camera mCamera;
    int cameraCurrentlyLocked;


    private ImageView preview_iv;
    private Handler handler;
    Bitmap rightBitmap;
    ImageView id_iv_flash_switch;
    CameraLine mCameraLine;

    private int defaultCameraId = 1;
    int cameraPosition = 1;

    private ScreenSwitchUtils mScreenSwitchInstance;
    private boolean isPortrait = true;
    private int orientationState = ScreenSwitchUtils.ORIENTATION_HEAD_IS_UP;
    private byte[] bytesData;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);//設置屏幕常亮
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);//去掉信息欄
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);//【旋轉問題】首先強制豎屏，手機橫過來時候 控件不變

        setContentView(R.layout.activity_camera);

        mScreenSwitchInstance = ScreenSwitchUtils.init(getApplicationContext());
        if (!Utils.checkCameraHardware(this)) {
            Toast.makeText(CameraActivity.this, "設備沒有攝像頭", Toast.LENGTH_SHORT).show();
            return;
        }
        mCameraLine = (CameraLine) findViewById(R.id.id_cl);
        preview_iv = (ImageView) findViewById(R.id.id_preview_iv);
        RelativeLayout id_rl_cp_view = (RelativeLayout) findViewById(R.id.id_rl_cp_view);
        DoubleClickConfig.registerDoubleClickListener(id_rl_cp_view, new DoubleClickConfig.OnDoubleClickListener() {

            @Override
            public void OnSingleClick(View v) {
                zoomDown();//單機縮小
            }

            @Override
            public void OnDoubleClick(View v) {
                zoomUp();//雙擊放大
            }
        });

        id_iv_flash_switch = (ImageView) findViewById(R.id.id_iv_flash_switch);

        handler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                if (msg.what == FLAG_AUTO_FOCUS) {
                    if (mCamera != null && safeToTakePicture && !TextUtils.isEmpty(mCamera.getParameters().getFlashMode())) {
                        mCamera.startPreview();
                        mCamera.autoFocus(null);
                    }

                    handler.sendEmptyMessageDelayed(FLAG_AUTO_FOCUS, FOCUS_DURATION);

                } else if (msg.what == TAKE_PHOTO_FINISH) {
                    // byte[] bitmapByte= (byte[]) msg.obj;
                    if (msg.obj == null) {
                        return;
                    }
                    String filePath = msg.obj.toString();
                    Intent intent = new Intent(CameraActivity.this, PreviewActivity.class);
                    intent.putExtra("filePath", filePath);
                    CameraActivity.this.startActivity(intent);
                }
            }
        };

        Log.d("CameraSurfaceView", "CameraSurfaceView onCreate currentThread : " + Thread.currentThread());
        // 得到屏幕的大小
        WindowManager wManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
        Display display = wManager.getDefaultDisplay();
        mScreenHeight = display.getHeight();
        mScreenWidth = display.getWidth();
        viewHeight = mScreenWidth / 2;
        mPreview = (CameraPreview) findViewById(R.id.camera_preview);

        startCamera();
    }

    @Override
    protected void onStart() {
        super.onStart();
        //【重力感應處理】
        mScreenSwitchInstance.start(this);
    }

    @Override
    protected void onStop() {
        super.onStop();
        //【重力感應處理】
        mScreenSwitchInstance.stop();
    }

    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.id_iv_shutter:
                stopFocus();
                takePicture(null, null, this);
                break;
            case R.id.id_iv_flash_switch:
                toggleFlash();
                break;
            case R.id.id_iv_config_line:
                mCameraLine.changeLineStyle();
                break;
            case R.id.id_iv_change:
                changeCameraTwo();
                break;
            default:

                break;
        }
    }

    @Override
    protected void onResume() {
        super.onResume();

        startCamera();
    }

    public void changeCameraTwo() {
        //切換前後攝像頭
        int cameraCount = 0;
        Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
        cameraCount = Camera.getNumberOfCameras();//得到攝像頭的個數
        for (int i = 0; i < cameraCount; i++) {
            Camera.getCameraInfo(i, cameraInfo);//得到每一個攝像頭的信息
            if (cameraPosition == 1) {
                Toast.makeText(this, "1現在是後置，變更爲前置", Toast.LENGTH_SHORT).show();
                //現在是後置，變更爲前置
                if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {//代表攝像頭的方位，CAMERA_FACING_FRONT前置      CAMERA_FACING_BACK後置
                    mCamera.stopPreview();//停掉原來攝像頭的預覽
                    releaseCamera();
                    mCamera = Camera.open(i);//打開當前選中的攝像頭
                    try {
                        mCamera.setPreviewDisplay(mPreview.getLouisSurfaceHolder());//通過surfaceview顯示取景畫面
                        // mCamera.setDisplayOrientation(90); //
                        mPreview.setCamera(mCamera);
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    mCamera.startPreview();//開始預覽
                    cameraPosition = 0;
                    break;
                }
            } else {
                Toast.makeText(this, "2現在是前置， 變更爲後置", Toast.LENGTH_SHORT).show();
                //現在是前置， 變更爲後置
                if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {//代表攝像頭的方位，CAMERA_FACING_FRONT前置      CAMERA_FACING_BACK後置
                    mCamera.stopPreview();//停掉原來攝像頭的預覽
                    releaseCamera();
                    mCamera = Camera.open(i);//打開當前選中的攝像頭
                    try {
                        mCamera.setPreviewDisplay(mPreview.getLouisSurfaceHolder());//通過surfaceview顯示取景畫面
                        // mCamera.setDisplayOrientation(90); //
                        mPreview.setCamera(mCamera);
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    mCamera.startPreview();//開始預覽
                    cameraPosition = 1;
                    break;
                }
            }

        }
    }

    private void startCamera() {
        // Open the default i.e. the first rear facing camera.
        try {
            if (mCamera == null) {
                mCamera = Camera.open();
            }
        } catch (Exception e) {
            e.printStackTrace();
            Toast.makeText(this, "啓動照相機失敗，請檢查設備並打開權限", Toast.LENGTH_SHORT).show();
        }
        cameraCurrentlyLocked = defaultCameraId;
        mPreview.setCamera(mCamera);

        startFocus();
    }

    @Override
    protected void onPause() {
        super.onPause();
        stopFocus();
        releaseCamera();
    }

    /**
     * 開啓自動對焦
     */
    private void startFocus() {
        stopFocus();
        handler.sendEmptyMessageDelayed(FLAG_AUTO_FOCUS, FOCUS_DURATION);
    }

    /**
     * 關閉自動對焦
     */
    private void stopFocus() {
        handler.removeMessages(FLAG_AUTO_FOCUS);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        releaseCamera();
    }

    /**
     * 釋放mCamera
     */
    private void releaseCamera() {
        // Because the Camera object is a shared resource, it's very
        // important to release it when the activity is paused.
        if (mCamera != null) {
            mPreview.setCamera(null);
            mCamera.release();
            mCamera = null;
        }
    }

    /**
     * 拍照
     *
     * @param shutter
     * @param raw
     * @param jpeg
     */
    public void takePicture(Camera.ShutterCallback shutter, Camera.PictureCallback raw,
                            Camera.PictureCallback jpeg) {
        if (mCamera != null) {
            if (safeToTakePicture) {
                mCamera.takePicture(shutter, raw, jpeg);
                safeToTakePicture = false;
            }
        }
    }

    /**
     * 縮小
     */
    public void zoomDown() {
        if (mCamera == null) {
            return;
        }
        Camera.Parameters p = mCamera.getParameters();
        if (!p.isZoomSupported()) return;

        if (zoomValue > 0) {
            zoomValue--;
        } else {
            zoomValue = 0;
            // Toast.makeText(getApplicationContext(), "已縮小到最小級別", Toast.LENGTH_SHORT).show();
            return;
        }
        int value = (int) (1F * zoomValue / ZOOM_FACTOR * p.getMaxZoom());
        p.setZoom(value);
        mCamera.setParameters(p);
    }

    /**
     * 放大
     */
    public void zoomUp() {
        if (mCamera == null) {
            return;
        }
        Camera.Parameters p = mCamera.getParameters();
        if (!p.isZoomSupported()) return;

        if (zoomValue < ZOOM_FACTOR) {
            zoomValue++;
        } else {
            zoomValue = ZOOM_FACTOR;
            Toast.makeText(getApplicationContext(), "已放大到最大級別", Toast.LENGTH_SHORT).show();
            return;
        }
        int value = (int) (1F * zoomValue / ZOOM_FACTOR * p.getMaxZoom());
        p.setZoom(value);
        mCamera.setParameters(p);
    }

    /**
     * 開關閃光燈
     * 持續的亮燈FLASH_MODE_TORCH
     * 閃一下FLASH_MODE_ON
     * 關閉模式FLASH_MODE_OFF
     * 自動感應是否要用閃光燈FLASH_MODE_AUTO
     */
    public void toggleFlash() {
        if (mCamera == null) {
            return;
        }

        Camera.Parameters p = mCamera.getParameters();
        if (Camera.Parameters.FLASH_MODE_OFF.equals(p.getFlashMode())) {
            p.setFlashMode(Camera.Parameters.FLASH_MODE_ON);
            mCamera.setParameters(p);
            id_iv_flash_switch.setImageDrawable(getResources().getDrawable(R.mipmap.camera_flash_on));
        } else if (Camera.Parameters.FLASH_MODE_ON.equals(p.getFlashMode())) {
            p.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
            mCamera.setParameters(p);
            id_iv_flash_switch.setImageDrawable(getResources().getDrawable(R.mipmap.camera_flash_auto));
        } else if (Camera.Parameters.FLASH_MODE_AUTO.equals(p.getFlashMode())) {
            p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);//持續的亮燈
            mCamera.setParameters(p);
            id_iv_flash_switch.setImageDrawable(getResources().getDrawable(R.mipmap.camera_flash_light));
        } else if (Camera.Parameters.FLASH_MODE_TORCH.equals(p.getFlashMode())) {
            p.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
            mCamera.setParameters(p);
            id_iv_flash_switch.setImageDrawable(getResources().getDrawable(R.mipmap.camera_flash_off));
        } else {
            Toast.makeText(this, "Flash mode setting is not supported.", Toast.LENGTH_SHORT).show();
        }

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == FLAG_CHOOCE_PICTURE && resultCode == RESULT_OK) {
            Uri uri = data.getData();
            String imgPath = getUrl(uri);
            Log.d("", "CameraSurfaceView imgPath : " + imgPath);
        }
    }

    @Override
    public void onPictureTaken(byte[] data, Camera camera) {

        if (data == null || data.length <= 0) {
            safeToTakePicture = true;
            return;
        }

        Log.d("CameraSurfaceView", "CameraSurfaceView onPictureTaken data.length : " + data.length);
        isPortrait = mScreenSwitchInstance.isPortrait();
        orientationState = mScreenSwitchInstance.getOrientationState();
        Log.i("xxx", "louis==xx==isPortrait：" + isPortrait);
        Log.i("xxx", "louis==xx==orientationState：" + orientationState);
        // 保存圖片
        bytesData = data;
        safeToTakePicture = true;
        handleAndSaveBitmap(data);
    }

    @Override
    public void onShutter() {
        Log.d("CameraSurfaceView", "CameraSurfaceView onShutter");
    }

    /**
     * 處理拍照圖片並保存
     *
     * @param data
     */
    private synchronized void handleAndSaveBitmap(byte[] data) {
        // 保存圖片
        //### Bitmap b = BitmapFactory.decodeByteArray(data, 0, data.length);
        Bitmap b = Utils.Bytes2Bitmap(data);

        if (cameraPosition == 1) {
            //後置攝像頭
            //rightBitmap = Utils.rotate(b, 0);
            rightBitmap = Utils.rotate(b, 90);//擺正位置
            //rightBitmap = Utils.rotate(b, 180);
            // rightBitmap = Utils.rotate(b, 270);
            //根據重力感應 更正旋轉
            switch (orientationState) {
                case ScreenSwitchUtils.ORIENTATION_HEAD_IS_UP:
                    break;
                case ScreenSwitchUtils.ORIENTATION_HEAD_IS_DOWN:
                    rightBitmap = Utils.rotate(rightBitmap, 180);
                    break;
                case ScreenSwitchUtils.ORIENTATION_HEAD_IS_LEFT:
                    rightBitmap = Utils.rotate(rightBitmap, 270);
                    break;
                case ScreenSwitchUtils.ORIENTATION_HEAD_IS_RIGHT:
                    rightBitmap = Utils.rotate(rightBitmap, 90);
                    break;
            }
        } else {
            //前置攝像頭
            rightBitmap = Utils.rotate(b, 270);//擺正位置
            //根據重力感應 更正旋轉
            switch (orientationState) {
                case ScreenSwitchUtils.ORIENTATION_HEAD_IS_UP:
                    break;
                case ScreenSwitchUtils.ORIENTATION_HEAD_IS_DOWN:
                    rightBitmap = Utils.rotate(rightBitmap, 180);
                    break;
                case ScreenSwitchUtils.ORIENTATION_HEAD_IS_LEFT:
                    rightBitmap = Utils.rotate(rightBitmap, 90);
                    break;
                case ScreenSwitchUtils.ORIENTATION_HEAD_IS_RIGHT:
                    rightBitmap = Utils.rotate(rightBitmap, 270);
                    break;
            }
        }

        String filePath = saveImageFile(rightBitmap);
        Message message = handler.obtainMessage();
        message.what = TAKE_PHOTO_FINISH;
        message.obj = filePath;
        message.sendToTarget();
    }

    private String saveImageFile(Bitmap bmp) {
        String filePath = null;
        File file = Utils.getDiskCacheDir(this, "bitmap");
        if (!file.exists()) {
            file.mkdirs();
        }
        File f = new File(file, System.currentTimeMillis() + ".jpg");
        try {
            BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(f));
            bmp.compress(Bitmap.CompressFormat.JPEG, 100, bos);
            bos.flush();
            bos.close();
            filePath = f.getAbsolutePath();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {

            if (bmp != null && !bmp.isRecycled()) {
                bmp.recycle();
                bmp = null;
            }
        }
        //   /storage/sdcard0/Android/data/com.example.dell.facedetection/cache/bitmap/1522393623105.jpg
        return filePath;
    }

    /**
     * 獲取從相冊中選擇的圖片的據對路徑
     *
     * @param uri
     * @return
     */
    private String getUrl(Uri uri) {
        if (uri == null) {
            return null;
        }

        String[] proj = {MediaStore.Images.Media.DATA};
        Cursor actualimagecursor = managedQuery(uri, proj, null, null, null);
        int actual_image_column_index = actualimagecursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        actualimagecursor.moveToFirst();
        String img_path = actualimagecursor.getString(actual_image_column_index);
        return TextUtils.isEmpty(img_path) ? null : img_path;
    }

    /**
     * 重力感應導致橫豎屏切換的條件下：獲取當前屏幕旋轉角度，要是鎖定豎屏就一直返回0了。。。
     *
     * @param activity
     * @return 0表示是豎屏; 90表示是左橫屏; 180表示是反向豎屏; 270表示是右橫屏
     */
    public static int getDisplayRotation(Activity activity) {
        if (activity == null) {
            return 0;
        }

        int rotation = activity.getWindowManager().getDefaultDisplay()
                .getRotation();
        switch (rotation) {
            case Surface.ROTATION_0:
                return 0;
            case Surface.ROTATION_90:
                return 90;
            case Surface.ROTATION_180:
                return 180;
            case Surface.ROTATION_270:
                return 270;
        }
        return 0;
    }

    public String saveImageFilePath() {
        String imageFilePath = Environment.getExternalStorageDirectory().getPath();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy_MM_dd");
        imageFilePath = imageFilePath + File.separator + "TongueImage";

        IfNotExistMkdir(imageFilePath);

        String subPath = File.separator + sdf.format(new Date());
        imageFilePath += subPath;

        IfNotExistMkdir(imageFilePath);

        SimpleDateFormat hms = new SimpleDateFormat("HHMMSS");
        String FileName = hms.format(new Date());
        return imageFilePath = File.separator + imageFilePath + File.separator + FileName + ".jpg";
    }

    private void IfNotExistMkdir(String filePath) {
        File file = new File(filePath);
        if (!file.exists()) {
            try {
                file.mkdir();
            } catch (Exception e) {
                //no do
            }


        }
    }

    public void saveToSDCard(byte[] data) throws IOException {
        // Log.d(TAG, "saveToSDCard");
        Date date = new Date();
        SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmss"); // 格式化時間
        String filename = format.format(date) + ".jpg";
        File fileFolder = new File(Environment.getExternalStorageDirectory() + "/ansen/");// Environment.getRootDirectory()
        if (!fileFolder.exists()) {
            fileFolder.mkdir();
        }
        File jpgFile = new File(fileFolder, filename);
        FileOutputStream outputStream = new FileOutputStream(jpgFile); // 文件輸出流
        outputStream.write(data);
        outputStream.close();
        mCamera.startPreview(); // 拍完照後，重新開始預覽
        if (false) {
            Bitmap b = Utils.BytesToBitmap(data);
            // 獲取手機屏幕的寬高
            WindowManager windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
            int windowWidth = windowManager.getDefaultDisplay().getWidth();
            int windowHight = windowManager.getDefaultDisplay().getHeight();
            Bitmap bitmap = Bitmap.createBitmap(b, 0, 0, windowWidth, windowHight);
            // 圖片壓縮
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
            outputStream.flush();

        }
    }


}

使用截圖：

預覽圖片：

選擇圖片：

CSDN下載地址