    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.util;
    018
    019    import java.io.IOException;
    020    import java.io.InputStream;
    021    import java.net.URL;
    022    import java.util.Properties;
    023
    024    import org.apache.logging.log4j.Logger;
    025    import org.apache.logging.log4j.status.StatusLogger;
    026
    027    /**
    028     * <em>Consider this class private.</em>
    029     * <p>
    030     * Helps access properties. This utility provides a method to override system properties by specifying properties
    031     * in a properties file.
    032     * </p>
    033     */
    034    public final class PropertiesUtil {
    035
    036        private static final PropertiesUtil LOG4J_PROPERTIES = new PropertiesUtil("log4j2.component.properties");
    037
    038        private static final Logger LOGGER = StatusLogger.getLogger();
    039
    040        private final Properties props;
    041
    042        /**
    043         * Constructs a PropertiesUtil using a given Properties object as its source of defined properties.
    044         *
    045         * @param props the Properties to use by default
    046         */
    047        public PropertiesUtil(final Properties props) {
    048            this.props = props;
    049        }
    050
    051        /**
    052         * Loads and closes the given property input stream.
    053         * If an error occurs, log to the status logger.
    054         *
    055         * @param in
    056         *            a property input stream.
    057         * @param source
    058         *            a source object describing the source, like a resource string
    059         *            or a URL.
    060         * @return a new Properties object
    061         */
    062        static Properties loadClose(final InputStream in, final Object source) {
    063            final Properties props = new Properties();
    064            if (null != in) {
    065                try {
    066                    props.load(in);
    067                } catch (final IOException e) {
    068                    LOGGER.error("Unable to read {}", source, e);
    069                } finally {
    070                    try {
    071                        in.close();
    072                    } catch (final IOException e) {
    073                        LOGGER.error("Unable to close {}", source, e);
    074                    }
    075                }
    076            }
    077            return props;
    078        }
    079
    080        /**
    081         * Constructs a PropertiesUtil for a given properties file name on the classpath. The properties specified in this
    082         * file are used by default. If a property is not defined in this file, then the equivalent system property is
    083         * used.
    084         *
    085         * @param propertiesFileName the location of properties file to load
    086         */
    087        public PropertiesUtil(final String propertiesFileName) {
    088            @SuppressWarnings("IOResourceOpenedButNotSafelyClosed")
    089            final Properties properties = new Properties();
    090            for (final URL url : LoaderUtil.findResources(propertiesFileName)) {
    091                InputStream in = null;
    092                try {
    093                    in = url.openStream();
    094                    properties.load(in);
    095                } catch (final IOException ioe) {
    096                    LOGGER.error("Unable to read {}", url.toString(), ioe);
    097                } finally {
    098                    if (in != null) {
    099                        try {
    100                            in.close();
    101                        } catch (final IOException ioe) {
    102                            LOGGER.error("Unable to close {}", url.toString(), ioe);
    103                        }
    104                    }
    105                }
    106            }
    107            this.props = properties;
    108        }
    109
    110        /**
    111         * Returns the PropertiesUtil used by Log4j.
    112         *
    113         * @return the main Log4j PropertiesUtil instance.
    114         */
    115        public static PropertiesUtil getProperties() {
    116            return LOG4J_PROPERTIES;
    117        }
    118
    119        /**
    120         * Gets the named property as a String.
    121         *
    122         * @param name the name of the property to look up
    123         * @return the String value of the property or {@code null} if undefined.
    124         */
    125        public String getStringProperty(final String name) {
    126            String prop = null;
    127            try {
    128                prop = System.getProperty(name);
    129            } catch (final SecurityException ignored) {
    130                // Ignore
    131            }
    132            return prop == null ? props.getProperty(name) : prop;
    133        }
    134
    135        /**
    136         * Gets the named property as an integer.
    137         *
    138         * @param name         the name of the property to look up
    139         * @param defaultValue the default value to use if the property is undefined
    140         * @return the parsed integer value of the property or {@code defaultValue} if it was undefined or could not be
    141         * parsed.
    142         */
    143        public int getIntegerProperty(final String name, final int defaultValue) {
    144            String prop = null;
    145            try {
    146                prop = System.getProperty(name);
    147            } catch (final SecurityException ignored) {
    148                // Ignore
    149            }
    150            if (prop == null) {
    151                prop = props.getProperty(name);
    152            }
    153            if (prop != null) {
    154                try {
    155                    return Integer.parseInt(prop);
    156                } catch (final Exception ignored) {
    157                    return defaultValue;
    158                }
    159            }
    160            return defaultValue;
    161        }
    162
    163        /**
    164         * Gets the named property as a long.
    165         *
    166         * @param name         the name of the property to look up
    167         * @param defaultValue the default value to use if the property is undefined
    168         * @return the parsed long value of the property or {@code defaultValue} if it was undefined or could not be
    169         * parsed.
    170         */
    171        public long getLongProperty(final String name, final long defaultValue) {
    172            String prop = null;
    173            try {
    174                prop = System.getProperty(name);
    175            } catch (final SecurityException ignored) {
    176                // Ignore
    177            }
    178            if (prop == null) {
    179                prop = props.getProperty(name);
    180            }
    181            if (prop != null) {
    182                try {
    183                    return Long.parseLong(prop);
    184                } catch (final Exception ignored) {
    185                    return defaultValue;
    186                }
    187            }
    188            return defaultValue;
    189        }
    190
    191        /**
    192         * Gets the named property as a String.
    193         *
    194         * @param name         the name of the property to look up
    195         * @param defaultValue the default value to use if the property is undefined
    196         * @return the String value of the property or {@code defaultValue} if undefined.
    197         */
    198        public String getStringProperty(final String name, final String defaultValue) {
    199            final String prop = getStringProperty(name);
    200            return (prop == null) ? defaultValue : prop;
    201        }
    202
    203        /**
    204         * Gets the named property as a boolean value. If the property matches the string {@code "true"} (case-insensitive),
    205         * then it is returned as the boolean value {@code true}. Any other non-{@code null} text in the property is
    206         * considered {@code false}.
    207         *
    208         * @param name the name of the property to look up
    209         * @return the boolean value of the property or {@code false} if undefined.
    210         */
    211        public boolean getBooleanProperty(final String name) {
    212            return getBooleanProperty(name, false);
    213        }
    214
    215        /**
    216         * Gets the named property as a boolean value.
    217         *
    218         * @param name         the name of the property to look up
    219         * @param defaultValue the default value to use if the property is undefined
    220         * @return the boolean value of the property or {@code defaultValue} if undefined.
    221         */
    222        public boolean getBooleanProperty(final String name, final boolean defaultValue) {
    223            final String prop = getStringProperty(name);
    224            return (prop == null) ? defaultValue : "true".equalsIgnoreCase(prop);
    225        }
    226
    227        /**
    228         * Return the system properties or an empty Properties object if an error occurs.
    229         * @return The system properties.
    230         */
    231        public static Properties getSystemProperties() {
    232            try {
    233                return new Properties(System.getProperties());
    234            } catch (final SecurityException ex) {
    235                LOGGER.error("Unable to access system properties.", ex);
    236                // Sandboxed - can't read System Properties
    237                return new Properties();
    238            }
    239        }
    240    }