我对android很陌生，出于某种原因，我必须实现一个代码，默认情况下打开前置摄像头而不是后置摄像头。我的最低 SDK 是 API 9，目标 SDK 是 API 21。我有一个 PicturePlugin.Java 文件，代码是：
public class PicturePlugin extends CordovaPlugin
{
private String callback="data";
private int IMAGE_TAKEN=1;
private CallbackContext callbackContext;
private String TAG="FilePlugin";
private int imageWidth,imageHeight;
private String imagePath;
private File destImageFile;
private String mode = "BACK";
private static String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
Locale.getDefault()).format(new Date());
CameraManager manager;
private static final String TAG1 = null ;
public boolean execute(String action, JSONArray args, CallbackContext callbackContext)
{
this.callbackContext = callbackContext;
this.cordova.getActivity().getApplicationContext().getPackageName();
try
{
JSONObject object=(JSONObject) args.get(0);
imageWidth=object.getInt("targetWidth");
imageHeight=object.getInt("targetHeight");
if(object.has("mode")){
if(object.getString("mode").equals("FRONT")){
mode = "FRONT";
openFrontFacingCamera();
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra("android.intent.extras.CAMERA_FACING", android.hardware.Camera.CameraInfo.CAMERA_FACING_FRONT);
}
}else{
mode = "BACK";
}
Intent camera=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
imagePath = getCapturedImageExternal();
destImageFile = new File(imagePath);
camera.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(destImageFile));
this.cordova.setActivityResultCallback(PicturePlugin.this);
cordova.getActivity().startActivityForResult(camera,IMAGE_TAKEN);
}
catch (Exception e)
{
Log.i(TAG, "Exception "+e.getMessage());
callbackContext.error("failed");
}
return true;
}
private Camera openFrontFacingCamera()
{
int cameraCount = 0;
Camera cam = null;
Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
cameraCount = Camera.getNumberOfCameras();
for ( int camId = 0; camId < cameraCount; camId++ ) {
Camera.getCameraInfo( camId, cameraInfo );
if ( cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT ) {
try {
cam = Camera.open( camId );
} catch (RuntimeException e) {
Log.e(TAG1, "Camera failed to open: " + e.getLocalizedMessage());
}
}
}
return cam;
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent)
{
if (requestCode == IMAGE_TAKEN && resultCode == Activity.RESULT_OK) {
File finalFile = null;
File fileTobeDeleted = null;
Bitmap photo = null;
File sd = new File(Environment.getExternalStorageDirectory(),
Constants.GOBIZMO_IMAGE_DIR);
String destinationImagePath = File.separator
+ Constants.TEMP_CAMERA_IMAGE + ".JPEG";
File destination = new File(sd, destinationImagePath);
sd.setWritable(true);
try {
String encoded;
imagePath = destImageFile.getAbsolutePath();
finalFile = new File(imagePath);
fileTobeDeleted = new File(imagePath);
int angle = getAngle(finalFile.getAbsolutePath());
if (finalFile.exists()) {
photo = BitmapFactory.decodeFile(finalFile
.getAbsolutePath());
Matrix matrix = new Matrix();
matrix.postRotate(angle);
Bitmap scaledBitmap = Bitmap.createScaledBitmap(photo, imageWidth, imageHeight, true);
photo = Bitmap.createBitmap(scaledBitmap, 0, 0, imageWidth, imageHeight, matrix, true);
// //////New orientation fix for all
// devices///////////////////////
try {
ByteArrayOutputStream stream = new ByteArrayOutputStream();
photo.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
encoded = Base64.encodeToString(byteArray, Base64.DEFAULT);
Log.e("base 64 image", encoded);
JSONObject object = new JSONObject();
object.put(callback, encoded);
finalFile.delete();
fileTobeDeleted.delete();
//imagePath = destination.getPath();
if(new File(imagePath).exists()){
new File(imagePath).delete();
}
callbackContext.success(encoded);
} catch (Exception e) {
e.printStackTrace();
Log.i(TAG, "onActivityResult " + e.getMessage());
finalFile.delete();
fileTobeDeleted.delete();
if(new File(imagePath).exists()){
new File(imagePath).delete();
}
callbackContext.error("failed");
}
}
} catch (Exception exp) {
exp.printStackTrace();
Log.i(TAG, "onActivityResult " + exp.getMessage());
try {
finalFile.delete();
fileTobeDeleted.delete();
imagePath = destination.getPath();
if(new File(imagePath).exists()){
new File(imagePath).delete();
}
callbackContext.error("failed");
}catch(Exception innerexception){
innerexception.printStackTrace();
}
}
}
}
public Uri getImageUri(Context inContext, Bitmap inImage)
{
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
inImage.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
String path = Images.Media.insertImage(inContext.getContentResolver(), inImage, "Title", null);
return Uri.parse(path);
}
public String getRealPathFromURI(Uri uri)
{
Cursor cursor = cordova.getActivity().getContentResolver().query(uri, null, null, null, null);
cursor.moveToFirst();
int idx = cursor.getColumnIndex(Images.ImageColumns.DATA);
return cursor.getString(idx);
}
public static String getCapturedImageExternal() {
// External sdcard location
File mediaStorageDir = new File(
android.os.Environment.getExternalStorageDirectory(),
"Gobizmo image");
// Create the storage directory if it does not exist
if (!mediaStorageDir.exists()){
mediaStorageDir.mkdirs();
}
if (!mediaStorageDir.exists() && !mediaStorageDir.mkdirs()) {
Log.d(Constants.GOBIZMO_IMAGE_DIR, "Oops! Failed create "
+ Constants.GOBIZMO_IMAGE_DIR + " directory");
return null;
}
// Create a timestamp
return mediaStorageDir.getPath() + File.separator + Constants.TEMP_CAMERA_IMAGE
+ ".JPEG";
}
public static String getRealPathFromURI(Context context, Uri contentUri) {
String filepath = "";
String uriPath = contentUri.toString();
// Handle local file and remove url encoding
if (uriPath.startsWith("file://")) {
filepath = uriPath.replace("file://", "");
try {
return URLDecoder.decode(filepath, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
try {
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = context.getContentResolver().query(contentUri,
projection, null, null, null);
if (cursor != null && cursor.getCount() != 0) {
int column_index = cursor
.getColumnIndex(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
filepath = cursor.getString(column_index);
}
} catch (Exception e) {
Log.e("Path Error", e.toString());
}
return filepath;
}
private int getAngle(String path)
{
int angle=0;
try
{
ExifInterface ei = new ExifInterface(path);
int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
Log.i(TAG, "getAngle "+orientation);
switch(orientation)
{
case ExifInterface.ORIENTATION_ROTATE_90:
angle=90;
break;
case ExifInterface.ORIENTATION_ROTATE_180:
angle=180;
break;
case ExifInterface.ORIENTATION_ROTATE_270 :
angle=270;
default:
angle=0;
}
}
catch(Exception ex)
{
Log.i("getAngle", "getAngle :: "+ex.getMessage());
}
return angle;
}
}
请帮我。这是我的第一个插件处理。