001/*
002 * jPOS Project [http://jpos.org]
003 * Copyright (C) 2000-2026 jPOS Software SRL
004 *
005 * This program is free software: you can redistribute it and/or modify
006 * it under the terms of the GNU Affero General Public License as
007 * published by the Free Software Foundation, either version 3 of the
008 * License, or (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
013 * GNU Affero General Public License for more details.
014 *
015 * You should have received a copy of the GNU Affero General Public License
016 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
017 */
018
019package org.jpos.util;
020
021import java.io.PrintStream;
022
023/**
024 * Abstract class for LogEventWriter implementations.
025 *
026 * Ensures that derived classes close the PrintStream since some of them
027 * may wrap it in an outer stream.
028 *
029 * Default write implementation is what is currently used by SimpleLogListener
030 * with an additional null check on the passed in LogEvent.
031 *
032 * @author Alwyn Schoeman
033 * @since 2.1.4
034 */
035public abstract class BaseLogEventWriter implements LogEventWriter {
036    /** Default constructor for subclass instantiation. */
037    protected BaseLogEventWriter() {}
038    PrintStream p;
039
040    @Override
041    public void setPrintStream(PrintStream p) {
042        if (p == null) {
043            close();
044            return;
045        }
046        if (this.p == p) return;
047        if (this.p != null) close();
048        this.p = p;
049    }
050
051    @Override
052    public synchronized void close() {
053        if (p != null) {
054            p.close();
055            p = null;
056        }
057    }
058
059    @Override
060    public void write(LogEvent ev) {
061        if (p != null && ev != null) {
062            ev.dump(p, "");
063            p.flush();
064        }
065    }
066}