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
018package org.apache.logging.log4j.core.appender.rolling.action;
019
020import java.nio.file.Path;
021import java.util.List;
022import java.util.Objects;
023
024import javax.script.SimpleBindings;
025
026import org.apache.logging.log4j.Logger;
027import org.apache.logging.log4j.core.Core;
028import org.apache.logging.log4j.core.config.Configuration;
029import org.apache.logging.log4j.core.config.plugins.Plugin;
030import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
031import org.apache.logging.log4j.core.config.plugins.PluginElement;
032import org.apache.logging.log4j.core.config.plugins.PluginFactory;
033import org.apache.logging.log4j.core.script.AbstractScript;
034import org.apache.logging.log4j.core.script.ScriptFile;
035import org.apache.logging.log4j.core.script.ScriptRef;
036import org.apache.logging.log4j.status.StatusLogger;
037
038/**
039 * A condition of the {@link DeleteAction} where a user-provided script selects the files to delete from a provided
040 * list. The specified script may be a {@link Script}, a {@link ScriptFile} or a {@link ScriptRef}.
041 *
042 * @see #createCondition(AbstractScript, Configuration)
043 */
044@Plugin(name = "ScriptCondition", category = Core.CATEGORY_NAME, printObject = true)
045public class ScriptCondition {
046    private static Logger LOGGER = StatusLogger.getLogger();
047
048    private final AbstractScript script;
049    private final Configuration configuration;
050
051    /**
052     * Constructs a new ScriptCondition.
053     *
054     * @param script the script that can select files to delete
055     * @param configuration configuration containing the StrSubstitutor passed to the script
056     */
057    public ScriptCondition(final AbstractScript script, final Configuration configuration) {
058        this.script = Objects.requireNonNull(script, "script");
059        this.configuration = Objects.requireNonNull(configuration, "configuration");
060        if (!(script instanceof ScriptRef)) {
061            configuration.getScriptManager().addScript(script);
062        }
063    }
064
065    /**
066     * Executes the script
067     *
068     * @param baseDir
069     * @param candidates
070     * @return
071     */
072    @SuppressWarnings("unchecked")
073    public List<PathWithAttributes> selectFilesToDelete(final Path basePath, final List<PathWithAttributes> candidates) {
074        final SimpleBindings bindings = new SimpleBindings();
075        bindings.put("basePath", basePath);
076        bindings.put("pathList", candidates);
077        bindings.putAll(configuration.getProperties());
078        bindings.put("configuration", configuration);
079        bindings.put("substitutor", configuration.getStrSubstitutor());
080        bindings.put("statusLogger", LOGGER);
081        final Object object = configuration.getScriptManager().execute(script.getName(), bindings);
082        return (List<PathWithAttributes>) object;
083    }
084
085    /**
086     * Creates the ScriptCondition.
087     *
088     * @param script The script to run. This may be a {@link Script}, a {@link ScriptFile} or a {@link ScriptRef}. The
089     *            script must return a {@code List<PathWithAttributes>}. When the script is executed, it is provided the
090     *            following bindings:
091     *            <ul>
092     *            <li>basePath - the directory from where the {@link DeleteAction Delete} action started scanning for
093     *            files to delete. Can be used to relativize the paths in the pathList.</li>
094     *            <li>pathList - a {@code java.util.List} containing {@link PathWithAttribute} objects. (The script is
095     *            free to modify and return this list.)</li>
096     *            <li>substitutor - a {@link StrSubstitutor} that can be used to look up variables embedded in the base
097     *            dir or other properties
098     *            <li>statusLogger - the {@link StatusLogger} that can be used to log events during script execution
099     *            <li>any properties declared in the configuration</li>
100     *            </ul>
101     * @param configuration the configuration
102     * @return A ScriptCondition.
103     */
104    @PluginFactory
105    public static ScriptCondition createCondition(@PluginElement("Script") final AbstractScript script,
106            @PluginConfiguration final Configuration configuration) {
107
108        if (script == null) {
109            LOGGER.error("A Script, ScriptFile or ScriptRef element must be provided for this ScriptCondition");
110            return null;
111        }
112        if (script instanceof ScriptRef) {
113            if (configuration.getScriptManager().getScript(script.getName()) == null) {
114                LOGGER.error("ScriptCondition: No script with name {} has been declared.", script.getName());
115                return null;
116            }
117        }
118        return new ScriptCondition(script, configuration);
119    }
120}