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