Android 微信打开文件URI 转成真实路径, File的Lenght=0的问题。

import android.annotation.TargetApi;
import android.app.Activity;
import android.content.ContentUris;
import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.ProviderInfo;
import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.support.v4.content.FileProvider;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.List;

public class GetRealPath {
    /**
     * 从uri获取path
     *
     * @param uri content://media/external/file/109009
     *            <p>
     *            FileProvider适配
     *            content://com.tencent.mobileqq.fileprovider/external_files/storage/emulated/0/Tencent/QQfile_recv/
     *            content://com.tencent.mm.external.fileprovider/external/tencent/MicroMsg/Download/
     */
    public static String getFilePathFromContentUri(Context context, Uri uri) {
        if (null == uri) return null;
        String data = null;

        String[] filePathColumn = {MediaStore.MediaColumns.DATA, MediaStore.MediaColumns.DISPLAY_NAME};
        Cursor cursor = context.getContentResolver().query(uri, filePathColumn, null, null, null);
        if (null != cursor) {
            if (cursor.moveToFirst()) {
                int index = cursor.getColumnIndex(MediaStore.MediaColumns.DATA);
                if (index > -1) {
                    data = cursor.getString(index);
                } else {
                    int nameIndex = cursor.getColumnIndex(MediaStore.MediaColumns.DISPLAY_NAME);
                    String fileName = cursor.getString(nameIndex);
                    data = getPathFromInputStreamUri(context, uri, fileName);
                }
            }
            cursor.close();
        }
        return data;
    }

    /**
     * 用流拷贝文件一份到自己APP私有目录下
     *
     * @param context
     * @param uri
     * @param fileName
     */
    private static String getPathFromInputStreamUri(Context context, Uri uri, String fileName) {
        InputStream inputStream = null;
        String filePath = null;

        if (uri.getAuthority() != null) {
            try {
                inputStream = context.getContentResolver().openInputStream(uri);
                File file = createTemporalFileFrom(context, inputStream, fileName);
                filePath = file.getPath();

            } catch (Exception e) {
            } finally {
                try {
                    if (inputStream != null) {
                        inputStream.close();
                    }
                } catch (Exception e) {
                }
            }
        }

        return filePath;
    }

    private static File createTemporalFileFrom(Context context, InputStream inputStream, String fileName)
            throws IOException {
        File targetFile = null;

        if (inputStream != null) {
            int read;
            byte[] buffer = new byte[8 * 1024];
            //自己定义拷贝文件路径
            targetFile = new File(context.getExternalCacheDir(), fileName);
            if (targetFile.exists()) {
                targetFile.delete();
            }
            OutputStream outputStream = new FileOutputStream(targetFile);

            while ((read = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, read);
            }
            outputStream.flush();

            try {
                outputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return targetFile;
    }
}