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	/*
	* Copyright (c) 2000, 2013, 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.*;

	/**
	* Stream based logging <tt>Handler</tt>.
	* <p>
	* This is primarily intended as a base class or support class to
	* be used in implementing other logging <tt>Handlers</tt>.
	* <p>
	* <tt>LogRecords</tt> are published to a given <tt>java.io.OutputStream</tt>.
	* <p>
	* <b>Configuration:</b>
	* By default each <tt>StreamHandler</tt> is initialized using the following
	* <tt>LogManager</tt> configuration properties where <tt><handler-name></tt>
	* 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 <tt>Handler</tt>
	* (defaults to <tt>Level.INFO</tt>). </li>
	* <li> <handler-name>.filter
	* specifies the name of a <tt>Filter</tt> class to use
	* (defaults to no <tt>Filter</tt>). </li>
	* <li> <handler-name>.formatter
	* specifies the name of a <tt>Formatter</tt> class to use
	* (defaults to <tt>java.util.logging.SimpleFormatter</tt>). </li>
	* <li> <handler-name>.encoding
	* the name of the character set encoding to use (defaults to
	* the default platform encoding). </li>
	* </ul>
	* <p>
	* For example, the properties for {@code StreamHandler} would be:
	* <ul>
	* <li> java.util.logging.StreamHandler.level=INFO </li>
	* <li> java.util.logging.StreamHandler.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>
	* @since 1.4
	*/

	public class StreamHandler extends Handler {
	private OutputStream output;
	private boolean doneHeader;
	private volatile Writer writer;

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

	setLevel(manager.getLevelProperty(cname +".level", Level.INFO));
	setFilter(manager.getFilterProperty(cname +".filter", null));
	setFormatter(manager.getFormatterProperty(cname +".formatter", new SimpleFormatter()));
	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;
	}
	}
	}

	/**
	* Create a <tt>StreamHandler</tt>, with no current output stream.
	*/
	public StreamHandler() {
	sealed = false;
	configure();
	sealed = true;
	}

	/**
	* Create a <tt>StreamHandler</tt> with a given <tt>Formatter</tt>
	* and output stream.
	* <p>
	* @param out the target output stream
	* @param formatter Formatter to be used to format output
	*/
	public StreamHandler(OutputStream out, Formatter formatter) {
	sealed = false;
	configure();
	setFormatter(formatter);
	setOutputStream(out);
	sealed = true;
	}

	/**
	* Change the output stream.
	* <P>
	* If there is a current output stream then the <tt>Formatter</tt>'s
	* tail string is written and the stream is flushed and closed.
	* Then the output stream is replaced with the new output stream.
	*
	* @param out New output stream. May not be null.
	* @exception SecurityException if a security manager exists and if
	* the caller does not have <tt>LoggingPermission("control")</tt>.
	*/
	protected synchronized void setOutputStream(OutputStream out) throws SecurityException {
	if (out == null) {
	throw new NullPointerException();
	}
	flushAndClose();
	output = out;
	doneHeader = false;
	String encoding = getEncoding();
	if (encoding == null) {
	writer = new OutputStreamWriter(output);
	} else {
	try {
	writer = new OutputStreamWriter(output, encoding);
	} catch (UnsupportedEncodingException ex) {
	// This shouldn't happen. The setEncoding method
	// should have validated that the encoding is OK.
	throw new Error("Unexpected exception " + ex);
	}
	}
	}

	/**
	* Set (or change) the character encoding used by this <tt>Handler</tt>.
	* <p>
	* The encoding should be set before any <tt>LogRecords</tt> are written
	* to the <tt>Handler</tt>.
	*
	* @param encoding The name of a supported character encoding.
	* May be null, to indicate the default platform encoding.
	* @exception SecurityException if a security manager exists and if
	* the caller does not have <tt>LoggingPermission("control")</tt>.
	* @exception UnsupportedEncodingException if the named encoding is
	* not supported.
	*/
	@Override
	public synchronized void setEncoding(String encoding)
	throws SecurityException, java.io.UnsupportedEncodingException {
	super.setEncoding(encoding);
	if (output == null) {
	return;
	}
	// Replace the current writer with a writer for the new encoding.
	flush();
	if (encoding == null) {
	writer = new OutputStreamWriter(output);
	} else {
	writer = new OutputStreamWriter(output, encoding);
	}
	}

	/**
	* Format and publish a <tt>LogRecord</tt>.
	* <p>
	* The <tt>StreamHandler</tt> first checks if there is an <tt>OutputStream</tt>
	* and if the given <tt>LogRecord</tt> has at least the required log level.
	* If not it silently returns. If so, it calls any associated
	* <tt>Filter</tt> to check if the record should be published. If so,
	* it calls its <tt>Formatter</tt> to format the record and then writes
	* the result to the current output stream.
	* <p>
	* If this is the first <tt>LogRecord</tt> to be written to a given
	* <tt>OutputStream</tt>, the <tt>Formatter</tt>'s "head" string is
	* written to the stream before the <tt>LogRecord</tt> is written.
	*
	* @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;
	}
	String msg;
	try {
	msg = getFormatter().format(record);
	} catch (Exception ex) {
	// We don't want to throw an exception here, but we
	// report the exception to any registered ErrorManager.
	reportError(null, ex, ErrorManager.FORMAT_FAILURE);
	return;
	}

	try {
	if (!doneHeader) {
	writer.write(getFormatter().getHead(this));
	doneHeader = true;
	}
	writer.write(msg);
	} catch (Exception ex) {
	// We don't want to throw an exception here, but we
	// report the exception to any registered ErrorManager.
	reportError(null, ex, ErrorManager.WRITE_FAILURE);
	}
	}


	/**
	* Check if this <tt>Handler</tt> would actually log a given <tt>LogRecord</tt>.
	* <p>
	* This method checks if the <tt>LogRecord</tt> has an appropriate level and
	* whether it satisfies any <tt>Filter</tt>. It will also return false if
	* no output stream has been assigned yet or the LogRecord is null.
	* <p>
	* @param record a <tt>LogRecord</tt>
	* @return true if the <tt>LogRecord</tt> would be logged.
	*
	*/
	@Override
	public boolean isLoggable(LogRecord record) {
	if (writer == null \|\| record == null) {
	return false;
	}
	return super.isLoggable(record);
	}

	/**
	* Flush any buffered messages.
	*/
	@Override
	public synchronized void flush() {
	if (writer != null) {
	try {
	writer.flush();
	} catch (Exception ex) {
	// We don't want to throw an exception here, but we
	// report the exception to any registered ErrorManager.
	reportError(null, ex, ErrorManager.FLUSH_FAILURE);
	}
	}
	}

	private synchronized void flushAndClose() throws SecurityException {
	checkPermission();
	if (writer != null) {
	try {
	if (!doneHeader) {
	writer.write(getFormatter().getHead(this));
	doneHeader = true;
	}
	writer.write(getFormatter().getTail(this));
	writer.flush();
	writer.close();
	} catch (Exception ex) {
	// We don't want to throw an exception here, but we
	// report the exception to any registered ErrorManager.
	reportError(null, ex, ErrorManager.CLOSE_FAILURE);
	}
	writer = null;
	output = null;
	}
	}

	/**
	* Close the current output stream.
	* <p>
	* The <tt>Formatter</tt>'s "tail" string is written to the stream before it
	* is closed. In addition, if the <tt>Formatter</tt>'s "head" string has not
	* yet been written to the stream, it will be written before the
	* "tail" string.
	*
	* @exception SecurityException if a security manager exists and if
	* the caller does not have LoggingPermission("control").
	*/
	@Override
	public synchronized void close() throws SecurityException {
	flushAndClose();
	}
	}

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