/*
* 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.logging.log4j.core.net;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.appender.AppenderRuntimeException;
import org.apache.logging.log4j.status.StatusLogger;
import java.io.IOException;
import java.io.OutputStream;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
/**
* OutputStream for UDP connections.
*/
public class DatagramOutputStream extends OutputStream {
/**
* Allow subclasses access to the status logger without creating another instance.
*/
protected static final Logger LOGGER = StatusLogger.getLogger();
private static final int SHIFT_1 = 8;
private static final int SHIFT_2 = 16;
private static final int SHIFT_3 = 24;
private DatagramSocket ds;
private final InetAddress address;
private final int port;
private byte[] data;
/**
* The Constructor.
* @param host The host to connect to.
* @param port The port on the host.
*/
public DatagramOutputStream(final String host, final int port) {
this.port = port;
try {
address = InetAddress.getByName(host);
} catch (final UnknownHostException ex) {
final String msg = "Could not find host " + host;
LOGGER.error(msg, ex);
throw new AppenderRuntimeException(msg, ex);
}
try {
ds = new DatagramSocket();
} catch (final SocketException ex) {
final String msg = "Could not instantiate DatagramSocket to " + host;
LOGGER.error(msg, ex);
throw new AppenderRuntimeException(msg, ex);
}
}
@Override
public synchronized void write(final byte[] bytes, final int offset, final int length) throws IOException {
copy(bytes, offset, length);
}
@Override
public synchronized void write(final int i) throws IOException {
copy(new byte[] {(byte) (i >>> SHIFT_3), (byte) (i >>> SHIFT_2), (byte) (i >>> SHIFT_1), (byte) i}, 0, 4);
}
@Override
public synchronized void write(final byte[] bytes) throws IOException {
copy(bytes, 0, bytes.length);
}
@Override
public synchronized void flush() throws IOException {
if (this.data != null && this.ds != null && this.address != null) {
final DatagramPacket packet = new DatagramPacket(data, data.length, address, port);
ds.send(packet);
}
data = null;
}
@Override
public synchronized void close() throws IOException {
if (ds != null) {
if (data != null) {
flush();
}
ds.close();
ds = null;
}
}
private void copy(final byte[] bytes, final int offset, final int length) {
final int index = data == null ? 0 : data.length;
final byte[] copy = new byte[length + index];
if (data != null) {
System.arraycopy(data, 0, copy, 0, index);
}
System.arraycopy(bytes, offset, copy, index, length);
data = copy;
}
}