Android 4.4以上 根据uri获取路径的方法

当我们选择图片以后，返回的是Uri，此时我们要把路径存储到数据库，必须将其转换成String类型。

URI:  //content://com.android.providers.media.documents/document/image%3A255779

转换后的路径：/storage/emulated/0/DCIM/Camera/IMG_20160117_132926.jpg

转换的方法：getPath

import android.annotation.SuppressLint;import android.content.ContentUris;import android.content.Context;import android.database.Cursor;import android.net.Uri;import android.os.Build;import android.os.Environment;import android.provider.DocumentsContract;import android.provider.MediaStore;public class GetPathFromUri4kitkat {    /**     * 专为Android4.4设计的从Uri获取文件绝对路径，以前的方法已不好使     */    @SuppressLint("NewApi")    public static String getPath(final Context context, final Uri uri) {         final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;         // DocumentProvider        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {            // ExternalStorageProvider            if (isExternalStorageDocument(uri)) {                final String docId = DocumentsContract.getDocumentId(uri);                final String[] split = docId.split(":");                final String type = split[0];                 if ("primary".equalsIgnoreCase(type)) {                    return Environment.getExternalStorageDirectory() + "/" + split[1];                }                 // TODO handle non-primary volumes            }            // DownloadsProvider            else if (isDownloadsDocument(uri)) {                 final String id = DocumentsContract.getDocumentId(uri);                final Uri contentUri = ContentUris.withAppendedId(                        Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));                 return getDataColumn(context, contentUri, null, null);            }            // MediaProvider            else if (isMediaDocument(uri)) {                final String docId = DocumentsContract.getDocumentId(uri);                final String[] split = docId.split(":");                final 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;                }                 final String selection = "_id=?";                final String[] selectionArgs = new String[] { split[1] };                 return getDataColumn(context, contentUri, selection, selectionArgs);            }        }        // MediaStore (and general)        else if ("content".equalsIgnoreCase(uri.getScheme())) {            return getDataColumn(context, uri, null, null);        }        // File        else if ("file".equalsIgnoreCase(uri.getScheme())) {            return uri.getPath();        }         return null;    }     /**     * Get the value of the data column for this Uri. This is useful for     * MediaStore Uris, and other file-based ContentProviders.     *      * @param context     *            The context.     * @param uri     *            The Uri to query.     * @param selection     *            (Optional) Filter used in the query.     * @param selectionArgs     *            (Optional) Selection arguments used in the query.     * @return The value of the _data column, which is typically a file path.     */    public static 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;    }     /**     * @param uri     *            The Uri to check.     * @return Whether the Uri authority is ExternalStorageProvider.     */    public static boolean isExternalStorageDocument(Uri uri) {        return "com.android.externalstorage.documents".equals(uri.getAuthority());    }     /**     * @param uri     *            The Uri to check.     * @return Whether the Uri authority is DownloadsProvider.     */    public static boolean isDownloadsDocument(Uri uri) {        return "com.android.providers.downloads.documents".equals(uri.getAuthority());    }     /**     * @param uri     *            The Uri to check.     * @return Whether the Uri authority is MediaProvider.     */    public static boolean isMediaDocument(Uri uri) {        return "com.android.providers.media.documents".equals(uri.getAuthority());    }}