io.joshworks.snappy.maven.tools.FileUtils Maven / Gradle / Ivy
/*
* Copyright 2012-2015 the original author or authors.
*
* 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 io.joshworks.snappy.maven.tools;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
* Utilities for manipulating files and directories in Spring Boot tooling.
*
* @author Dave Syer
* @author Phillip Webb
*/
public abstract class FileUtils {
/**
* Utility to remove duplicate files from an "output" directory if they already exist
* in an "origin". Recursively scans the origin directory looking for files (not
* directories) that exist in both places and deleting the copy.
*
* @param outputDirectory the output directory
* @param originDirectory the origin directory
*/
public static void removeDuplicatesFromOutputDirectory(File outputDirectory,
File originDirectory) {
if (originDirectory.isDirectory()) {
for (String name : originDirectory.list()) {
File targetFile = new File(outputDirectory, name);
if (targetFile.exists() && targetFile.canWrite()) {
if (!targetFile.isDirectory()) {
targetFile.delete();
} else {
FileUtils.removeDuplicatesFromOutputDirectory(targetFile,
new File(originDirectory, name));
}
}
}
}
}
/**
* Generate a SHA.1 Hash for a given file.
*
* @param file the file to hash
* @return the hash value as a String
* @throws IOException if the file cannot be read
*/
public static String sha1Hash(File file) throws IOException {
try {
DigestInputStream inputStream = new DigestInputStream(
new FileInputStream(file), MessageDigest.getInstance("SHA-1"));
try {
byte[] buffer = new byte[4098];
while (inputStream.read(buffer) != -1) {
// Read the entire stream
}
return bytesToHex(inputStream.getMessageDigest().digest());
} finally {
inputStream.close();
}
} catch (NoSuchAlgorithmException ex) {
throw new IllegalStateException(ex);
}
}
private static String bytesToHex(byte[] bytes) {
StringBuilder hex = new StringBuilder();
for (byte b : bytes) {
hex.append(String.format("%02x", b));
}
return hex.toString();
}
}