Android中URI的转换关于file和content相互转换工具类

调用时：File imageFile = getFileByUri(Uri);

工具类：

public File getFileByUri(Uri uri) {
String path = null;
if ("file".equals(uri.getScheme())) {
path = uri.getEncodedPath();
if (path != null) {
path = Uri.decode(path);
ContentResolver cr = this.getContentResolver();
StringBuffer buff = new StringBuffer();
buff.append("(").append( MediaStore.Images.ImageColumns.DATA).append("=").append("'" + path + "'").append(")");
Cursor cur = cr.query( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[] {  MediaStore.Images.ImageColumns._ID, MediaStore.Images.ImageColumns.DATA }, buff.toString(), null, null);
int index = 0;
int dataIdx = 0;
for (cur.moveToFirst(); !cur.isAfterLast(); cur.moveToNext()) {
index = cur.getColumnIndex( MediaStore.Images.ImageColumns._ID);
index = cur.getInt(index);
dataIdx = cur.getColumnIndex( MediaStore.Images.ImageColumns.DATA);
path = cur.getString(dataIdx);
}
cur.close();
if (index == 0) {
} else {
Uri u = Uri.parse("content://media/external/images/media/" + index);
System.out.println("temp uri is :" + u);
}
}
if (path != null) {
return new File(path);
}
} else if ("content".equals(uri.getScheme())) {
// 4.2.2以后
String[] proj = { MediaStore.Images.Media.DATA };
Cursor cursor = this.getContentResolver().query(uri, proj, null, null, null);
if (cursor.moveToFirst()) {
int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
path = cursor.getString(columnIndex);
}
cursor.close();

return new File(path);
} else {
//            Log.i(TAG, "Uri Scheme:" + uri.getScheme());
}
return null;
}