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	/*
	* Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/


	package java.util.logging;

	import java.io.*;
	import java.net.*;

	/**
	* Simple network logging {@code Handler}.
	* <p>
	* {@code LogRecords} are published to a network stream connection. By default
	* the {@code XMLFormatter} class is used for formatting.
	* <p>
	* <b>Configuration:</b>
	* By default each {@code SocketHandler} is initialized using the following
	* {@code LogManager} configuration properties where {@code <handler-name>}
	* refers to the fully-qualified class name of the handler.
	* If properties are not defined
	* (or have invalid values) then the specified default values are used.
	* <ul>
	* <li> <handler-name>.level
	* specifies the default level for the {@code Handler}
	* (defaults to {@code Level.ALL}). </li>
	* <li> <handler-name>.filter
	* specifies the name of a {@code Filter} class to use
	* (defaults to no {@code Filter}). </li>
	* <li> <handler-name>.formatter
	* specifies the name of a {@code Formatter} class to use
	* (defaults to {@code java.util.logging.XMLFormatter}). </li>
	* <li> <handler-name>.encoding
	* the name of the character set encoding to use (defaults to
	* the default platform encoding). </li>
	* <li> <handler-name>.host
	* specifies the target host name to connect to (no default). </li>
	* <li> <handler-name>.port
	* specifies the target TCP port to use (no default). </li>
	* </ul>
	* <p>
	* For example, the properties for {@code SocketHandler} would be:
	* <ul>
	* <li> java.util.logging.SocketHandler.level=INFO </li>
	* <li> java.util.logging.SocketHandler.formatter=java.util.logging.SimpleFormatter </li>
	* </ul>
	* <p>
	* For a custom handler, e.g. com.foo.MyHandler, the properties would be:
	* <ul>
	* <li> com.foo.MyHandler.level=INFO </li>
	* <li> com.foo.MyHandler.formatter=java.util.logging.SimpleFormatter </li>
	* </ul>
	* <p>
	* The output IO stream is buffered, but is flushed after each
	* {@code LogRecord} is written.
	*
	* @since 1.4
	*/

	public class SocketHandler extends StreamHandler {
	private Socket sock;
	private String host;
	private int port;

	/**
	* Create a {@code SocketHandler}, using only {@code LogManager} properties
	* (or their defaults).
	* @throws IllegalArgumentException if the host or port are invalid or
	* are not specified as LogManager properties.
	* @throws IOException if we are unable to connect to the target
	* host and port.
	*/
	public SocketHandler() throws IOException {
	// configure with specific defaults for SocketHandler
	super(Level.ALL, new XMLFormatter(), null);

	LogManager manager = LogManager.getLogManager();
	String cname = getClass().getName();
	port = manager.getIntProperty(cname + ".port", 0);
	host = manager.getStringProperty(cname + ".host", null);

	try {
	connect();
	} catch (IOException ix) {
	System.err.println("SocketHandler: connect failed to " + host + ":" + port);
	throw ix;
	}
	}

	/**
	* Construct a {@code SocketHandler} using a specified host and port.
	*
	* The {@code SocketHandler} is configured based on {@code LogManager}
	* properties (or their default values) except that the given target host
	* and port arguments are used. If the host argument is empty, but not
	* null String then the localhost is used.
	*
	* @param host target host.
	* @param port target port.
	*
	* @throws IllegalArgumentException if the host or port are invalid.
	* @throws IOException if we are unable to connect to the target
	* host and port.
	*/
	public SocketHandler(String host, int port) throws IOException {
	// configure with specific defaults for SocketHandler
	super(Level.ALL, new XMLFormatter(), null);

	this.port = port;
	this.host = host;

	connect();
	}

	private void connect() throws IOException {
	// Check the arguments are valid.
	if (port == 0) {
	throw new IllegalArgumentException("Bad port: " + port);
	}
	if (host == null) {
	throw new IllegalArgumentException("Null host name: " + host);
	}

	// Try to open a new socket.
	sock = new Socket(host, port);
	OutputStream out = sock.getOutputStream();
	BufferedOutputStream bout = new BufferedOutputStream(out);
	setOutputStreamPrivileged(bout);
	}

	/**
	* Close this output stream.
	*
	* @throws SecurityException if a security manager exists and if
	* the caller does not have {@code LoggingPermission("control")}.
	*/
	@Override
	public synchronized void close() throws SecurityException {
	super.close();
	if (sock != null) {
	try {
	sock.close();
	} catch (IOException ix) {
	// drop through.
	}
	}
	sock = null;
	}

	/**
	* Format and publish a {@code LogRecord}.
	*
	* @param record description of the log event. A null record is
	* silently ignored and is not published
	*/
	@Override
	public synchronized void publish(LogRecord record) {
	if (!isLoggable(record)) {
	return;
	}
	super.publish(record);
	flush();
	}
	}

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