org.apache.log4j.helpers.SyslogWriter Maven / Gradle / Ivy
/*
* 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.log4j.helpers;
import java.io.Writer;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.DatagramPacket;
import java.net.UnknownHostException;
import java.net.SocketException;
import java.io.IOException;
import java.net.URL;
import java.net.MalformedURLException;
/**
SyslogWriter is a wrapper around the java.net.DatagramSocket class
so that it behaves like a java.io.Writer.
@since 0.7.3
*/
public class SyslogWriter extends Writer {
final int SYSLOG_PORT = 514;
/**
* Host string from last constructed SyslogWriter.
* @deprecated
*/
static String syslogHost;
private InetAddress address;
private final int port;
private DatagramSocket ds;
/**
* Constructs a new instance of SyslogWriter.
* @param syslogHost host name, may not be null. A port
* may be specified by following the name or IPv4 literal address with
* a colon and a decimal port number. To specify a port with an IPv6
* address, enclose the IPv6 address in square brackets before appending
* the colon and decimal port number.
*/
public
SyslogWriter(final String syslogHost) {
SyslogWriter.syslogHost = syslogHost;
if (syslogHost == null) {
throw new NullPointerException("syslogHost");
}
String host = syslogHost;
int urlPort = -1;
//
// If not an unbracketed IPv6 address then
// parse as a URL
//
if (host.indexOf("[") != -1 || host.indexOf(':') == host.lastIndexOf(':')) {
try {
URL url = new URL("http://" + host);
if (url.getHost() != null) {
host = url.getHost();
// if host is a IPv6 literal, strip off the brackets
if(host.startsWith("[") && host.charAt(host.length() - 1) == ']') {
host = host.substring(1, host.length() - 1);
}
urlPort = url.getPort();
}
} catch(MalformedURLException e) {
LogLog.error("Malformed URL: will attempt to interpret as InetAddress.", e);
}
}
if (urlPort == -1) {
urlPort = SYSLOG_PORT;
}
port = urlPort;
try {
this.address = InetAddress.getByName(host);
}
catch (UnknownHostException e) {
LogLog.error("Could not find " + host +
". All logging will FAIL.", e);
}
try {
this.ds = new DatagramSocket();
}
catch (SocketException e) {
e.printStackTrace();
LogLog.error("Could not instantiate DatagramSocket to " + host +
". All logging will FAIL.", e);
}
}
public
void write(char[] buf, int off, int len) throws IOException {
this.write(new String(buf, off, len));
}
public
void write(final String string) throws IOException {
if(this.ds != null && this.address != null) {
byte[] bytes = string.getBytes();
//
// syslog packets must be less than 1024 bytes
//
int bytesLength = bytes.length;
if (bytesLength >= 1024) {
bytesLength = 1024;
}
DatagramPacket packet = new DatagramPacket(bytes, bytesLength,
address, port);
ds.send(packet);
}
}
public
void flush() {}
public void close() {
if (ds != null) {
ds.close();
}
}
}