Java14LoggingHandler.java

/*
 * Copyright (c) 2009-2015
 * 	IT-Consulting Stephan Schloepke (http://www.schloepke.de/)
 * 	klemm software consulting Mirko Klemm (http://www.klemm-scs.com/)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package org.jbasics.testing;

import org.jbasics.checker.ContractCheck;

import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.logging.ErrorManager;
import java.util.logging.Formatter;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogRecord;

/**
 * A Java14 Logging facility handler. Mostly this handler is designed to be used in testing facilities rather than
 * running in a production enviroment.
 *
 * @author Stephan Schloepke
 * @since 1.0.0
 */
public class Java14LoggingHandler extends Handler {
	private final Writer standardWriter;
	private final Writer errorWriter;
	private boolean standardHeaderWritten = false;
	private boolean errorHeaderWritten = false;
	private boolean closed = false;

	/**
	 * Constructs the logging handler for the {@link System#out} / {@link System#err} as default output and a newly
	 * created {@link Java14LoggingFormatter} and {@link Level#ALL}. <p> This should be used in testing only. </p>
	 */
	public Java14LoggingHandler() {
		this(Level.ALL, System.out, System.err, new Java14LoggingFormatter());
	}

	/**
	 * Constructs the logging handler.
	 *
	 * @param level     The logging level to use for this handler (Must not be null)
	 * @param output    The output to use for this handler (Must not be null)
	 * @param formatter The formatter to use (Must not be null)
	 */
	public Java14LoggingHandler(Level level, OutputStream output, OutputStream errorOutput, Formatter formatter) {
		setLevel(ContractCheck.mustNotBeNull(level, "level"));
		setFormatter(ContractCheck.mustNotBeNull(formatter, "formatter"));
		this.standardWriter = new OutputStreamWriter(output);
		if (output == errorOutput) {
			this.errorWriter = this.standardWriter;
		} else {
			this.errorWriter = new OutputStreamWriter(errorOutput);
		}
	}

	/**
	 * Constructs the logging handler for the {@link System#out} / {@link System#err} as default output and a newly
	 * created {@link Java14LoggingFormatter}.
	 *
	 * @param level The logging level to use for this handler (Must not be null)
	 */
	public Java14LoggingHandler(Level level) {
		this(level, System.out, System.err, new Java14LoggingFormatter());
	}

	/**
	 * Constructs the logging handler for the {@link System#out} / {@link System#err} as default output.
	 *
	 * @param level     The logging level to use for this handler (Must not be null)
	 * @param formatter The formatter to use (Must not be null)
	 */
	public Java14LoggingHandler(Level level, Formatter formatter) {
		this(level, System.out, System.err, formatter);
	}

	/*
	 * (non-Javadoc)
	 * @see java.util.logging.StreamHandler#publish(java.util.logging.LogRecord)
	 */
	@Override
	public synchronized void publish(final LogRecord record) {
		if (!isLoggable(record)) {
			return;
		}
		if (this.closed) {
			reportError("Already closed", null, ErrorManager.WRITE_FAILURE);
		}
		String msg;
		Formatter formatter;
		try {
			formatter = getFormatter();
			msg = formatter.format(record);
		} catch (Exception ex) {
			reportError("Could not obtain format", ex, ErrorManager.FORMAT_FAILURE);
			return;
		}
		try {
			if (record.getLevel() == Level.SEVERE) {
				if (!this.errorHeaderWritten) {
					this.errorWriter.write(formatter.getHead(this));
					this.errorHeaderWritten = true;
				}
				this.errorWriter.write(msg);
			} else {
				if (!this.standardHeaderWritten) {
					this.standardWriter.write(formatter.getHead(this));
					this.standardHeaderWritten = true;
				}
				this.standardWriter.write(msg);
			}
		} catch (Exception ex) {
			reportError("Could not write log record", ex, ErrorManager.WRITE_FAILURE);
		}
	}

	/*
	 * (non-Javadoc)
	 * @see java.util.logging.Handler#flush()
	 */
	@Override
	public synchronized void flush() {
		if (this.closed) return;
		try {
			this.errorWriter.flush();
			this.standardWriter.flush();
		} catch (Exception e) {
			reportError("Could not flush the output streams", e, ErrorManager.FLUSH_FAILURE);
		}
	}

	/*
	 * (non-Javadoc)
	 * @see java.util.logging.StreamHandler#close()
	 */
	@Override
	public synchronized void close() {
		if (this.closed) return;
		try {
			Formatter formatter = null;
			try {
				formatter = getFormatter();
			} catch (Exception ex) {
				reportError("Could not obtain format", ex, ErrorManager.FORMAT_FAILURE);
			}
			if (formatter != null) {
				if (!this.errorHeaderWritten) {
					this.errorWriter.write(formatter.getHead(this));
					this.errorHeaderWritten = true;
				}
				this.errorWriter.write(formatter.getTail(this));
				if (!this.standardHeaderWritten) {
					this.standardWriter.write(formatter.getHead(this));
					this.standardHeaderWritten = true;
				}
				this.standardWriter.write(formatter.getTail(this));
			}
			flush();
			this.closed = true;
		} catch (Exception e) {
			reportError("Could not close output streas", e, ErrorManager.CLOSE_FAILURE);
		}
	}
}