FileUtilities.java

/*
Copyright (c) Microsoft Open Technologies, Inc.
All Rights Reserved
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

THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED,
INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
MERCHANTABLITY OR NON-INFRINGEMENT.

See the Apache 2 License for the specific language governing permissions and limitations under the License.
*/

package com.msopentech.thali.toronionproxy;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class FileUtilities {
    private static final Logger LOG = LoggerFactory.getLogger(FileUtilities.class);

    /**
     * Closes both input and output streams when done.
     *
     * @param in  Stream to read from
     * @param out Stream to write to
     * @throws java.io.IOException - If close on input or output fails
     */
    public static void copy(InputStream in, OutputStream out) throws IOException {
        try {
            copyDoNotCloseInput(in, out);
        } finally {
            in.close();
        }
    }

    /**
     * Won't close the input stream when it's done, needed to handle ZipInputStreams
     *
     * @param in  Won't be closed
     * @param out Will be closed
     * @throws java.io.IOException - If close on output fails
     */
    public static void copyDoNotCloseInput(InputStream in, OutputStream out) throws IOException {
        try {
            byte[] buf = new byte[4096];
            while (true) {
                int read = in.read(buf);
                if (read == -1) break;
                out.write(buf, 0, read);
            }
        } finally {
            out.close();
        }
    }

    public static void listFilesToLog(File f) {
        if (f.isDirectory()) {
            for (File child : f.listFiles()) {
                listFilesToLog(child);
            }
        } else {
            LOG.info(f.getAbsolutePath());
        }
    }

    public static byte[] read(File f) throws IOException {
        byte[] b = new byte[(int) f.length()];
        FileInputStream in = new FileInputStream(f);
        try {
            int offset = 0;
            while (offset < b.length) {
                int read = in.read(b, offset, b.length - offset);
                if (read == -1) throw new EOFException();
                offset += read;
            }
            return b;
        } finally {
            in.close();
        }
    }

    /**
     * Reads the input stream, deletes fileToWriteTo if it exists and over writes it with the stream.
     *
     * @param readFrom      Stream to read from
     * @param fileToWriteTo File to write to
     * @throws java.io.IOException - If any of the file operations fail
     */
    public static void cleanInstallOneFile(InputStream readFrom, File fileToWriteTo) throws IOException {
        if (fileToWriteTo.exists() && fileToWriteTo.delete() == false) {
            throw new RuntimeException("Could not remove existing file " + fileToWriteTo.getName());
        }
        OutputStream out = new FileOutputStream(fileToWriteTo);
        FileUtilities.copy(readFrom, out);
    }

    public static void recursiveFileDelete(File fileOrDirectory) {
        if (fileOrDirectory.isDirectory()) {
            for (File child : fileOrDirectory.listFiles()) {
                recursiveFileDelete(child);
            }
        }

        if (fileOrDirectory.exists() && fileOrDirectory.delete() == false) {
            throw new RuntimeException("Could not delete directory " + fileOrDirectory.getAbsolutePath());
        }
    }

    /**
     * This has to exist somewhere! Why isn't it a part of the standard Java library?
     *
     * @param destinationDirectory Directory files are to be extracted to
     * @param zipFileInputStream   Stream to unzip
     * @throws java.io.IOException - If there are any file errors
     */
    public static void extractContentFromZip(File destinationDirectory, InputStream zipFileInputStream)
            throws IOException {
        ZipInputStream zipInputStream;
        try {
            zipInputStream = new ZipInputStream(zipFileInputStream);
            ZipEntry zipEntry;
            while ((zipEntry = zipInputStream.getNextEntry()) != null) {
                File file = new File(destinationDirectory, zipEntry.getName());
                if (zipEntry.isDirectory()) {
                    if (file.exists() == false && file.mkdirs() == false) {
                        throw new RuntimeException("Could not create directory " + file);
                    }
                } else {
                    if (file.exists() && file.delete() == false) {
                        throw new RuntimeException(
                                "Could not delete file in preparation for overwriting it. File - " +
                                        file.getAbsolutePath());
                    }

                    if (file.createNewFile() == false) {
                        throw new RuntimeException("Could not create file " + file);
                    }

                    OutputStream fileOutputStream = new FileOutputStream(file);
                    copyDoNotCloseInput(zipInputStream, fileOutputStream);
                }
            }
        } finally {
            if (zipFileInputStream != null) {
                zipFileInputStream.close();
            }
        }
    }
}