Android WebView 调用相机、相册，压缩图片后上传
声明：文中代码根据多篇博客进行修改，由本人缝合而成，对应地方会放出原文链接。
重写webChromeClient的onShowFileChooser方法
@Overridepublic boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {mUploadCallbackAboveL = filePathCallback;openAlbum();return true;}
fileChooserParams可以接收h5中input标签的一些参数，选择好文件后，将文件uri传递给filePathCallback。
原文链接：调用原生相机、相册
选择调用相机或相册
private void openAlbum() {// 指定拍照存储位置的方式调起相机String filePath = Environment.getExternalStorageDirectory() + File.separator+ Environment.DIRECTORY_PICTURES + File.separator;String fileName = "IMG_" + DateFormat.format("yyyyMMdd_hhmmss", Calendar.getInstance(Locale.CHINA)) + ".jpg";image = new File(filePath + fileName);imageUri = Uri.fromFile(image);Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);Intent Photo = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);Intent chooserIntent = Intent.createChooser(Photo, "选择照片");chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Parcelable[]{captureIntent});startActivityForResult(chooserIntent, REQUEST_CODE);}
通过imageUri保存调用相机拍照的照片的存储位置。用Intent打开选择相机、相册或文件夹的activity。
接收选择照片，或者拍照返回的uri
@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);if (requestCode == REQUEST_CODE) {if (mUploadCallbackAboveL != null) {chooseAbove(resultCode, data);} else {Toast.makeText(this, "发生错误", Toast.LENGTH_SHORT).show();}}}
choosAbove方法来处理获取后的uri，并回传给filePathCallback。
处理uri
具体的处理步骤，通过uri获取到图片的path，读取图片，压缩图片后重新存储，将压缩后的图片uri进行回传
（1）. chooseAbove方法
private void chooseAbove(int resultCode, Intent data) {if (RESULT_OK == resultCode) {updatePhotos();if (data != null) {//处理选择的照片Uri[] results;Uri uriData = data.getData();if (uriData != null) {results = new Uri[]{uriData};try {Uri compressImageUri = pressBmpFromBmp(uriToString(uriData));mUploadCallbackAboveL.onReceiveValue(new Uri[]{compressImageUri});} catch (Exception e) {e.printStackTrace();requestWritePermission();}} else {mUploadCallbackAboveL.onReceiveValue(null);}} else {//处理拍照的照片try {Uri compressImageUri = pressBmpFromBmp(imageUri.getPath());mUploadCallbackAboveL.onReceiveValue(new Uri[]{compressImageUri});} catch (Exception e) {e.printStackTrace();requestWritePermission();}}} else {mUploadCallbackAboveL.onReceiveValue(null);}mUploadCallbackAboveL = null;}
由于拍照的照片存储在imageUri，这里将拍照和相册选择分开处理，注意，如果没有选择照片，给filePathCallback传一个空值，防止上传只能点击一次后失效。
（2）. 压缩图片的工具类ImageCompressUtils
原文链接图片压缩工具类（解决了压缩后图片被旋转的问题）
public class ImageCompressUtils {/*** @param srcPath* @return* @description 将图片从本地读到内存时，即图片从File形式变为Bitmap形式* 特点：通过设置采样率，减少图片的像素，达到对内存中的Bitmao进行压缩* 方法说明: 该方法就是对Bitmap形式的图片进行压缩, 也就是通过设置采样率, 减少Bitmap的像素, 从而减少了它所占用的内存*/public static Uri compressBmpFromBmp(String srcPath) {// String srcPathStr = srcPath;BitmapFactory.Options newOptions = new BitmapFactory.Options();newOptions.inJustDecodeBounds = true;//只读边，不读内容Bitmap bitmap = BitmapFactory.decodeFile(srcPath, newOptions);newOptions.inJustDecodeBounds = false;int w = newOptions.outWidth;int h = newOptions.outHeight;float hh = 800f;float ww = 480f;int be = 1;if (w > h && w > ww) {be = (int) (newOptions.outWidth / ww);} else if (w < h && h > hh) {be = (int) (newOptions.outHeight / hh);}if (be <= 0)be = 1;newOptions.inSampleSize = be;//设置采样率newOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;//该模式是默认的，可不设newOptions.inPurgeable = true;//同时设置才会有效newOptions.inInputShareable = true;//当系统内存不够时候图片会自动被回收bitmap = BitmapFactory.decodeFile(srcPath, newOptions);int degree = readPictureDegree(srcPath);bitmap = rotateBitmap(bitmap, degree);return compressBmpToFile(bitmap);}/*** @param bmp* @description 将图片保存到本地时进行压缩, 即将图片从Bitmap形式变为File形式时进行压缩,* 特点是: File形式的图片确实被压缩了, 但是当你重新读取压缩后的file为 Bitmap是,它占用的内存并没有改变* 所谓的质量压缩，即为改变其图像的位深和每个像素的透明度，也就是说JPEG格式压缩后，原来图片中透明的元素将消失，所以这种格式很可能造成失真*/public static Uri compressBmpToFile(Bitmap bmp) {String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/shoppingMall/compressImgs/";File file = new File(path + System.currentTimeMillis() + ".jpg");//判断文件夹是否存在,如果不存在则创建文件夹if (!file.getParentFile().exists()) {file.getParentFile().mkdirs();}ByteArrayOutputStream baos = new ByteArrayOutputStream();int options = 80;press(pressFormat.JPEG, options, baos);while (baos.toByteArray().length / 1024 > 100) {baos.reset();options -= 10;press(pressFormat.JPEG, options, baos);}try {FileOutputStream fos = new FileOutputStream(file);fos.write(baos.toByteArray());fos.flush();fos.close();// copyExif(srcPathStr,file.getAbsolutePath());// return file.getAbsolutePath();return Uri.fromFile(file);} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}return null;}/*** 获取图片旋转角度** @param srcPath* @return*/private static int readPictureDegree(String srcPath) {int degree = 0;try {ExifInterface exifInterface = new ExifInterface(srcPath);int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);switch (orientation) {case ExifInterface.ORIENTATION_ROTATE_90:degree = 90;break;case ExifInterface.ORIENTATION_ROTATE_180:degree = 180;break;case ExifInterface.ORIENTATION_ROTATE_270:degree = 270;break;}} catch (IOException e) {e.printStackTrace();}return degree;}//处理图片旋转private static Bitmap rotateBitmap(Bitmap bitmap, int rotate) {if (bitmap == null)return null;int w = bitmap.getWidth();int h = bitmap.getHeight();// Setting post rotate to 90Matrix mtx = new Matrix();mtx.postRotate(rotate);return Bitmap.createBitmap(bitmap, 0, 0, w, h, mtx, true);}}
调用压缩方法，将压缩后的图片的uri传递给filePathCallback，上传结束。
5.需要注意的地方
如果应用没有文件存储的权限，要动态请求权限。一下是请求权限及其回调方法。
原文链接：动态获取文件存储权限
private void requestWritePermission() {if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, WRITE_PERMISSION);}}@Overridepublic void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {if (requestCode == WRITE_PERMISSION) {if (grantResults[0] != PackageManager.PERMISSION_GRANTED) {String message = "必须提供文件存储权限，否则无法正常使用.";AlertDialog.Builder localBuilder = new AlertDialog.Builder(webView.getContext());localBuilder.setMessage(message).setPositiveButton(getResources().getString(R.string.sure), new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {requestWritePermission();}});localBuilder.setCancelable(false);localBuilder.create().show();}}}
通过uri获取path的问题
imageUri保存的图片，通过getPath可以直接获取。但是相册和文件夹选择的uri，getPath获取到的路径在读取照片时却找不到。因此，使用如下方法，通过uri获取path。
原文地址：uri获取path
private String uriToString(Uri uri) {String path = null;if (ContentResolver.SCHEME_CONTENT.equals(uri.getScheme())) {if (DocumentsContract.isDocumentUri(this, uri)) {// ExternalStorageProviderif ("com.android.externalstorage.documents".equals(uri.getAuthority())) {String docId = DocumentsContract.getDocumentId(uri);String[] split = docId.split(":");String type = split[0];if ("primary".equalsIgnoreCase(type)) {path = Environment.getExternalStorageDirectory() + "/" + split[1];}} else if ("com.android.providers.downloads.documents".equals(uri.getAuthority())) {// DownloadsProviderString id = DocumentsContract.getDocumentId(uri);Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));path = getDataColumn(this, contentUri, null, null);} else if ("com.android.providers.media.documents".equals(uri.getAuthority())) {// MediaProviderString docId = DocumentsContract.getDocumentId(uri);String[] split = docId.split(":");String type = split[0];Uri contentUri = null;if ("image".equals(type)) {contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;} else if ("video".equals(type)) {contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;} else if ("audio".equals(type)) {contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;}String selection = "_id=?";String[] selectionArgs = new String[]{split[1]};path = getDataColumn(this, contentUri, selection, selectionArgs);}} else {path = getRealPathFromUri(this, uri);}}return path;}private String getRealPathFromUri(Context context, Uri contentUri) {Cursor cursor = null;try {String[] proj = {MediaStore.Files.FileColumns.DATA};cursor = context.getContentResolver().query(contentUri, proj, null, null, null);int column_index = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DATA);cursor.moveToFirst();return cursor.getString(column_index);} finally {if (cursor != null) {cursor.close();}}}private String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {Cursor cursor = null;final String column = "_data";final String[] projection = {column};try {cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);if (cursor != null && cursor.moveToFirst()) {final int column_index = cursor.getColumnIndexOrThrow(column);return cursor.getString(column_index);}} finally {if (cursor != null)cursor.close();}return null;}
拍照后，广播通知系统刷新文件
private void updatePhotos() {// 该广播即使多发（即选取照片成功时也发送）也没有关系，只是唤醒系统刷新媒体文件Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);intent.setData(imageUri);sendBroadcast(intent);}
