/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.karaf.util.properties;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.channels.FileLock;
import org.apache.felix.utils.properties.Properties;
public final class FileLockUtils {
private FileLockUtils() { }
public static interface Runnable {
void run(RandomAccessFile file) throws IOException;
}
public static interface Callable<T> {
T call(RandomAccessFile file) throws IOException;
}
public static interface RunnableWithProperties {
void run(Properties properties) throws IOException;
}
public static interface CallableWithProperties<T> {
T call(Properties properties) throws IOException;
}
public static void execute(File file, Runnable callback) throws IOException {
RandomAccessFile raf = new RandomAccessFile(file, "rw");
try {
FileLock lock = raf.getChannel().lock();
try {
callback.run(raf);
} finally {
lock.release();
}
} finally {
raf.close();
}
}
public static <T> T execute(File file, Callable<T> callback) throws IOException {
RandomAccessFile raf = new RandomAccessFile(file, "rw");
try {
FileLock lock = raf.getChannel().lock();
try {
return callback.call(raf);
} finally {
lock.release();
}
} finally {
raf.close();
}
}
public static void execute(File file, final RunnableWithProperties callback, final boolean writeToFile) throws IOException {
execute(file, new Runnable() {
public void run(RandomAccessFile file) throws IOException {
byte[] buffer = new byte[(int) file.length()];
file.readFully(buffer);
Properties props = new Properties();
props.load(new ByteArrayInputStream(buffer));
callback.run(props);
if (writeToFile) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
props.store(baos, null);
file.setLength(0);
file.write(baos.toByteArray());
}
}
});
}
public static <T> T execute(File file, final CallableWithProperties<T> callback, final boolean writeToFile) throws IOException {
return execute(file, new Callable<T>() {
public T call(RandomAccessFile file) throws IOException {
byte[] buffer = new byte[(int) file.length()];
file.readFully(buffer);
Properties props = new Properties();
props.load(new ByteArrayInputStream(buffer));
T result = callback.call(props);
if (writeToFile) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
props.store(baos, null);
file.setLength(0);
file.write(baos.toByteArray());
}
return result;
}
});
}
}