com.oracle.tools.io.FileHelper Maven / Gradle / Ivy
/*
* File: FileHelper.java
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* The contents of this file are subject to the terms and conditions of
* the Common Development and Distribution License 1.0 (the "License").
*
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the License by consulting the LICENSE.txt file
* distributed with this file, or by consulting https://oss.oracle.com/licenses/CDDL
*
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file LICENSE.txt.
*
* MODIFICATIONS:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*/
package com.oracle.tools.io;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.UUID;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
/**
* Common {@link File} utilities.
*
* Copyright (c) 2013. All Rights Reserved. Oracle Corporation.
* Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
*
* @author Brian Oliver
*/
public class FileHelper
{
/**
* Create a Temporary Folder.
*
* @return a File representing the temporary folder
*
* @throws IOException if the folder could not be created
*/
public static File createTemporaryFolder(String prefix) throws IOException
{
// the location of the system temporary folder
File systemTemporaryFolder = new File(System.getProperty("java.io.tmpdir"));
// the number of attempts to create a unique temporary folder
final int maximumAttempts = 100;
int attemptsRemaining = maximumAttempts;
// the resulting temporary folder
File temporaryFolder = null;
while (attemptsRemaining > 0 && temporaryFolder == null)
{
// we need some randomness for the folder name
String randomness = UUID.randomUUID().toString();
// does the folder already exist?
temporaryFolder = new File(systemTemporaryFolder, prefix + randomness);
if (temporaryFolder.exists())
{
temporaryFolder = null;
}
else
{
try
{
// attempt to create the folder
temporaryFolder.mkdir();
return temporaryFolder;
}
catch (Exception e)
{
temporaryFolder = null;
}
}
// next attempt!
attemptsRemaining--;
}
throw new IOException("Failed to create a unique temporary folder after " + maximumAttempts + " attempts.");
}
/**
* Attempt to recursively delete the specified file or folder.
*
* @param file a file representing the File or Folder to delete
*
* @return true if all files/folders have been deleted, false if only
* partial removal occurred
*/
public static boolean recursiveDelete(File file)
{
if (file != null && file.exists())
{
if (file.isDirectory())
{
for (File child : file.listFiles())
{
if (!recursiveDelete(child))
{
return false;
}
}
}
return file.delete();
}
else
{
return true;
}
}
/**
* Zips the specified files, including directories and nested directories into the specified zip file.
*
* @param files the {@link File}s (including directories) to zip
* @param baseFolderName the folder that will be created when unzipping the zip file
* @param toZipFile the zip file (that will be created)
*/
public static void zip(Iterable files,
String baseFolderName,
String toZipFile) throws FileNotFoundException, IOException
{
ZipOutputStream zip = new ZipOutputStream(new FileOutputStream(toZipFile));
if (files != null)
{
for (File file : files)
{
if (file.exists())
{
if (file.isDirectory())
{
addFolderToZip(file, baseFolderName, zip);
}
else
{
addFileToZip(file, baseFolderName, zip);
}
}
}
}
zip.flush();
zip.close();
}
/**
* Adds a specified {@link File} (that is not a folder) to the specified
* {@link ZipOutputStream}, the {@link File} being located in the specified parent
* folder.
*
* @param file a file representing the {@link File} to add
* @param parentFolderName the parent folder of the {@link File}
* @param zip the {@link ZipOutputStream} to which to write the {@link File}
*
* @throws IOException should any problems occur
*/
private static void addFileToZip(File file,
String parentFolderName,
ZipOutputStream zip) throws IOException
{
String parent = parentFolderName == null || parentFolderName.trim().isEmpty()
? "" : parentFolderName.trim() + "/";
if (file.exists())
{
zip.putNextEntry(new ZipEntry(parent + file.getName()));
BufferedInputStream inputStream = new BufferedInputStream(new FileInputStream(file));
byte[] buffer = new byte[16096];
int count = 0;
while ((count = inputStream.read(buffer)) != -1)
{
zip.write(buffer, 0, count);
}
zip.closeEntry();
}
}
/**
* Recursively adds the contents of the specified {@link File} representing a folder to the
* specified {@link ZipOutputStream}.
*
* @param folder a {@link File} representing a folder to add
* @param parentFolderName the parent folder of the {@link File}
* @param zip the {@link ZipOutputStream} to which to write the {@link File}
*
* @throws IOException should any problems occur
*/
private static void addFolderToZip(File folder,
String parentFolderName,
ZipOutputStream zip) throws IOException
{
String parent = parentFolderName == null || parentFolderName.trim().isEmpty()
? "" : parentFolderName.trim() + "/";
if (folder.exists())
{
File[] files = folder.listFiles();
if (files != null)
{
for (File file : files)
{
if (file.isDirectory())
{
addFolderToZip(file, parent + file.getName(), zip);
}
else
{
addFileToZip(file, parentFolderName, zip);
}
}
}
}
}
}