/*
 * @(#)SocketHandler.java	1.13 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */


package java.util.logging;

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

/**
 * Simple network logging <tt>Handler</tt>.
 * <p>
 * <tt>LogRecords</tt> are published to a network stream connection.  By default
 * the <tt>XMLFormatter</tt> class is used for formatting.
 * <p>
 * <b>Configuration:</b>
 * By default each <tt>SocketHandler</tt> is initialized using the following
 * <tt>LogManager</tt> configuration properties.  If properties are not defined
 * (or have invalid values) then the specified default values are used.
 * <ul>
 * <li>   java.util.logging.SocketHandler.level
 *	  specifies the default level for the <tt>Handler</tt>
 *	  (defaults to <tt>Level.ALL</tt>).
 * <li>   java.util.logging.SocketHandler.filter
 * 	  specifies the name of a <tt>Filter</tt> class to use
 *	  (defaults to no <tt>Filter</tt>).
 * <li>   java.util.logging.SocketHandler.formatter
 *	  specifies the name of a <tt>Formatter</tt> class to use 
 *	  (defaults to <tt>java.util.logging.XMLFormatter</tt>).
 * <li>   java.util.logging.SocketHandler.encoding 
 *	  the name of the character set encoding to use (defaults to
 *	  the default platform encoding).
 * <li>   java.util.logging.SocketHandler.host
 *	  specifies the target host name to connect to (no default).
 * <li>   java.util.logging.SocketHandler.port
 *	  specifies the target TCP port to use (no default).
 * </ul>
 * <p>
 * The output IO stream is buffered, but is flushed after each
 * <tt>LogRecord</tt> is written.
 *
 * @version 1.13, 01/23/03
 * @since 1.4
 */

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

    // Private method to configure a SocketHandler from LogManager
    // properties and/or default values as specified in the class
    // javadoc.
    private void configure() {
        LogManager manager = LogManager.getLogManager();
	String cname = SocketHandler.class.getName();

	setLevel(manager.getLevelProperty(cname +".level", Level.ALL));
	setFilter(manager.getFilterProperty(cname +".filter", null));
	setFormatter(manager.getFormatterProperty(cname +".formatter", new XMLFormatter()));
	try {
	    setEncoding(manager.getStringProperty(cname +".encoding", null));
	} catch (Exception ex) {
	    try {
	        setEncoding(null);
	    } catch (Exception ex2) {
		// doing a setEncoding with null should always work.
		// assert false;
	    }
	}
	port = manager.getIntProperty(cname + ".port", 0);
	host = manager.getStringProperty(cname + ".host", null);
    }


    /**
     * Create a <tt>SocketHandler</tt>, using only <tt>LogManager</tt> 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 {
	// We are going to use the logging defaults.
	sealed = false;
	configure();

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

    /**
     * Construct a <tt>SocketHandler</tt> using a specified host and port.
     *
     * The <tt>SocketHandler</tt> is configured based on <tt>LogManager</tt> 
     * properties (or their default values) except that the given target host
     * and port arguments are 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 {
	sealed = false;
	configure();
	sealed = true;
	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);
	setOutputStream(bout);
    }

    /**
     * Close this output stream.
     *
     * @exception  SecurityException  if a security manager exists and if
     *             the caller does not have <tt>LoggingPermission("control")</tt>.
     */
    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 <tt>LogRecord</tt>.
     *
     * @param  record  description of the log event
     */
    public synchronized void publish(LogRecord record) {
	if (!isLoggable(record)) {
	    return;
	}
	super.publish(record);
	flush();
    }
}