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 */
017package org.apache.logging.log4j.core.appender.db.jpa;
018
019import java.lang.reflect.Constructor;
020
021import org.apache.logging.log4j.core.Filter;
022import org.apache.logging.log4j.core.LogEvent;
023import org.apache.logging.log4j.core.appender.AbstractAppender;
024import org.apache.logging.log4j.core.appender.db.AbstractDatabaseAppender;
025import org.apache.logging.log4j.core.config.plugins.Plugin;
026import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
027import org.apache.logging.log4j.core.config.plugins.PluginElement;
028import org.apache.logging.log4j.core.config.plugins.PluginFactory;
029import org.apache.logging.log4j.core.helpers.Booleans;
030import org.apache.logging.log4j.core.helpers.Strings;
031
032/**
033 * This Appender writes logging events to a relational database using the Java Persistence API. It requires a
034 * pre-configured JPA persistence unit and a concrete implementation of the abstract
035 * {@link AbstractLogEventWrapperEntity} class decorated with JPA annotations.
036 *
037 * @see AbstractLogEventWrapperEntity
038 */
039@Plugin(name = "JPA", category = "Core", elementType = "appender", printObject = true)
040public final class JPAAppender extends AbstractDatabaseAppender<JPADatabaseManager> {
041    private final String description;
042
043    private JPAAppender(final String name, final Filter filter, final boolean ignoreExceptions,
044            final JPADatabaseManager manager) {
045        super(name, filter, ignoreExceptions, manager);
046        this.description = this.getName() + "{ manager=" + this.getManager() + " }";
047    }
048
049    @Override
050    public String toString() {
051        return this.description;
052    }
053
054    /**
055     * Factory method for creating a JPA appender within the plugin manager.
056     *
057     * @param name The name of the appender.
058     * @param ignore If {@code "true"} (default) exceptions encountered when appending events are logged; otherwise
059     *               they are propagated to the caller.
060     * @param filter The filter, if any, to use.
061     * @param bufferSize If an integer greater than 0, this causes the appender to buffer log events and flush whenever
062     *                   the buffer reaches this size.
063     * @param entityClassName The fully qualified name of the concrete {@link AbstractLogEventWrapperEntity}
064     *                        implementation that has JPA annotations mapping it to a database table.
065     * @param persistenceUnitName The name of the JPA persistence unit that should be used for persisting log events.
066     * @return a new JPA appender.
067     */
068    @PluginFactory
069    public static JPAAppender createAppender(
070            @PluginAttribute("name") final String name,
071            @PluginAttribute("ignoreExceptions") final String ignore,
072            @PluginElement("Filter") final Filter filter,
073            @PluginAttribute("bufferSize") final String bufferSize,
074            @PluginAttribute("entityClassName") final String entityClassName,
075            @PluginAttribute("persistenceUnitName") final String persistenceUnitName) {
076        if (Strings.isEmpty(entityClassName) || Strings.isEmpty(persistenceUnitName)) {
077            LOGGER.error("Attributes entityClassName and persistenceUnitName are required for JPA Appender.");
078            return null;
079        }
080
081        final int bufferSizeInt = AbstractAppender.parseInt(bufferSize, 0);
082        final boolean ignoreExceptions = Booleans.parseBoolean(ignore, true);
083
084        try {
085            @SuppressWarnings("unchecked")
086            final Class<? extends AbstractLogEventWrapperEntity> entityClass =
087                    (Class<? extends AbstractLogEventWrapperEntity>) Class.forName(entityClassName);
088
089            if (!AbstractLogEventWrapperEntity.class.isAssignableFrom(entityClass)) {
090                LOGGER.error("Entity class [{}] does not extend AbstractLogEventWrapperEntity.", entityClassName);
091                return null;
092            }
093
094            try {
095                entityClass.getConstructor();
096            } catch (final NoSuchMethodException e) {
097                LOGGER.error("Entity class [{}] does not have a no-arg constructor. The JPA provider will reject it.",
098                        entityClassName);
099                return null;
100            }
101
102            final Constructor<? extends AbstractLogEventWrapperEntity> entityConstructor =
103                    entityClass.getConstructor(LogEvent.class);
104
105            final String managerName = "jpaManager{ description=" + name + ", bufferSize=" + bufferSizeInt
106                    + ", persistenceUnitName=" + persistenceUnitName + ", entityClass=" + entityClass.getName() + "}";
107
108            final JPADatabaseManager manager = JPADatabaseManager.getJPADatabaseManager(
109                    managerName, bufferSizeInt, entityClass, entityConstructor, persistenceUnitName
110            );
111            if (manager == null) {
112                return null;
113            }
114
115            return new JPAAppender(name, filter, ignoreExceptions, manager);
116        } catch (final ClassNotFoundException e) {
117            LOGGER.error("Could not load entity class [{}].", entityClassName, e);
118            return null;
119        } catch (final NoSuchMethodException e) {
120            LOGGER.error("Entity class [{}] does not have a constructor with a single argument of type LogEvent.",
121                    entityClassName);
122            return null;
123        }
124    }
125}