common/util/src/com/android/compatibility/common/util/FileUtil.java

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.compatibility.common.util;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * A helper class for file related operations
 */
public class FileUtil {

    /**
     * Recursively delete given file or directory and all its contents.
     *
     * @param rootDir the directory or file to be deleted; can be null
     */
    public static void recursiveDelete(File rootDir) {
        if (rootDir != null) {
            if (rootDir.isDirectory()) {
                File[] childFiles = rootDir.listFiles();
                if (childFiles != null) {
                    for (File child : childFiles) {
                        recursiveDelete(child);
                    }
                }
            }
            rootDir.delete();
        }
    }

    /**
     * A helper method for writing stream data to file
     *
     * @param input the unbuffered input stream
     * @param destFile the dest file to write to
     */
    public static void writeToFile(InputStream input, File destFile) throws IOException {
        InputStream origStream = null;
        OutputStream destStream = null;
        try {
            origStream = new BufferedInputStream(input);
            destStream = new BufferedOutputStream(new FileOutputStream(destFile));
            StreamUtil.copyStreams(origStream, destStream);
        } finally {
            origStream.close();
            destStream.flush();
            destStream.close();
        }
    }

}