    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements. See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache license, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License. You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the license for the specific language governing permissions and
    015     * limitations under the license.
    016     */
    017    package org.apache.logging.log4j.status;
    018
    019    import java.io.IOException;
    020    import java.io.PrintStream;
    021
    022    import org.apache.logging.log4j.Level;
    023
    024    /**
    025     * StatusListener that writes to the Console.
    026     */
    027    @SuppressWarnings("UseOfSystemOutOrSystemErr")
    028    public class StatusConsoleListener implements StatusListener {
    029
    030        private Level level = Level.FATAL;
    031        private String[] filters;
    032        private final PrintStream stream;
    033
    034        /**
    035         * Creates the StatusConsoleListener using the supplied Level.
    036         * @param level The Level of status messages that should appear on the console.
    037         */
    038        public StatusConsoleListener(final Level level) {
    039            this(level, System.out);
    040        }
    041
    042        /**
    043         * Creates the StatusConsoleListener using the supplied Level. Make sure not to use a logger stream of some sort
    044         * to avoid creating an infinite loop of indirection!
    045         * @param level The Level of status messages that should appear on the console.
    046         * @param stream The PrintStream to write to.
    047         * @throws IllegalArgumentException if the PrintStream argument is {@code null}.
    048         */
    049        public StatusConsoleListener(final Level level, final PrintStream stream) {
    050            if (stream == null) {
    051                throw new IllegalArgumentException("You must provide a stream to use for this listener.");
    052            }
    053            this.level = level;
    054            this.stream = stream;
    055        }
    056
    057        /**
    058         * Sets the level to a new value.
    059         * @param level The new Level.
    060         */
    061        public void setLevel(final Level level) {
    062            this.level = level;
    063        }
    064
    065        /**
    066         * Return the Log Level for which the Listener should receive events.
    067         * @return the Log Level.
    068         */
    069        @Override
    070        public Level getStatusLevel() {
    071            return this.level;
    072        }
    073
    074        /**
    075         * Writes status messages to the console.
    076         * @param data The StatusData.
    077         */
    078        @Override
    079        public void log(final StatusData data) {
    080            if (!filtered(data)) {
    081                stream.println(data.getFormattedStatus());
    082            }
    083        }
    084
    085        /**
    086         * Adds package name filters to exclude.
    087         * @param filters An array of package names to exclude.
    088         */
    089        public void setFilters(final String... filters) {
    090            this.filters = filters;
    091        }
    092
    093        private boolean filtered(final StatusData data) {
    094            if (filters == null) {
    095                return false;
    096            }
    097            final String caller = data.getStackTraceElement().getClassName();
    098            for (final String filter : filters) {
    099                if (caller.startsWith(filter)) {
    100                    return true;
    101                }
    102            }
    103            return false;
    104        }
    105
    106        @Override
    107        public void close() throws IOException {
    108            // only want to close non-system streams
    109            if (this.stream != System.out && this.stream != System.err) {
    110                this.stream.close();
    111            }
    112        }
    113    }