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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements. See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache license, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License. You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the license for the specific language governing permissions and
15   * limitations under the license.
16   */
17  package org.apache.logging.log4j.core.appender.db.jpa;
18  
19  import java.io.Serializable;
20  import java.lang.reflect.Constructor;
21  
22  import javax.persistence.EntityManager;
23  import javax.persistence.EntityManagerFactory;
24  import javax.persistence.EntityTransaction;
25  import javax.persistence.Persistence;
26  
27  import org.apache.logging.log4j.core.LogEvent;
28  import org.apache.logging.log4j.core.appender.AppenderLoggingException;
29  import org.apache.logging.log4j.core.appender.ManagerFactory;
30  import org.apache.logging.log4j.core.appender.db.AbstractDatabaseManager;
31  
32  /**
33   * An {@link AbstractDatabaseManager} implementation for relational databases accessed via JPA.
34   */
35  public final class JpaDatabaseManager extends AbstractDatabaseManager {
36      private static final JPADatabaseManagerFactory FACTORY = new JPADatabaseManagerFactory();
37  
38      private final String entityClassName;
39      private final Constructor<? extends AbstractLogEventWrapperEntity> entityConstructor;
40      private final String persistenceUnitName;
41  
42      private EntityManagerFactory entityManagerFactory;
43  
44      private EntityManager entityManager;
45      private EntityTransaction transaction;
46  
47      private JpaDatabaseManager(final String name, final int bufferSize,
48                                 final Class<? extends AbstractLogEventWrapperEntity> entityClass,
49                                 final Constructor<? extends AbstractLogEventWrapperEntity> entityConstructor,
50                                 final String persistenceUnitName) {
51          super(name, bufferSize);
52          this.entityClassName = entityClass.getName();
53          this.entityConstructor = entityConstructor;
54          this.persistenceUnitName = persistenceUnitName;
55      }
56  
57      @Override
58      protected void startupInternal() {
59          this.entityManagerFactory = Persistence.createEntityManagerFactory(this.persistenceUnitName);
60      }
61  
62      @Override
63      protected boolean shutdownInternal() {
64          boolean closed = true;
65          if (this.entityManager != null || this.transaction != null) {
66              closed &= this.commitAndClose();
67          }
68          if (this.entityManagerFactory != null && this.entityManagerFactory.isOpen()) {
69              this.entityManagerFactory.close();
70          }
71          return closed;
72      }
73  
74      @Override
75      protected void connectAndStart() {
76          try {
77              this.entityManager = this.entityManagerFactory.createEntityManager();
78              this.transaction = this.entityManager.getTransaction();
79              this.transaction.begin();
80          } catch (final Exception e) {
81              throw new AppenderLoggingException(
82                      "Cannot write logging event or flush buffer; manager cannot create EntityManager or transaction.", e
83              );
84          }
85      }
86  
87      @Override
88      protected void writeInternal(final LogEvent event, final Serializable serializable) {
89          if (!this.isRunning() || this.entityManagerFactory == null || this.entityManager == null
90                  || this.transaction == null) {
91              throw new AppenderLoggingException(
92                      "Cannot write logging event; JPA manager not connected to the database.");
93          }
94  
95          AbstractLogEventWrapperEntity entity;
96          try {
97              entity = this.entityConstructor.newInstance(event);
98          } catch (final Exception e) {
99              throw new AppenderLoggingException("Failed to instantiate entity class [" + this.entityClassName + "].", e);
100         }
101 
102         try {
103             this.entityManager.persist(entity);
104         } catch (final Exception e) {
105             if (this.transaction != null && this.transaction.isActive()) {
106                 this.transaction.rollback();
107                 this.transaction = null;
108             }
109             throw new AppenderLoggingException("Failed to insert record for log event in JPA manager: " +
110                     e.getMessage(), e);
111         }
112     }
113 
114     @Override
115     protected boolean commitAndClose() {
116         boolean closed = true;
117         try {
118             if (this.transaction != null && this.transaction.isActive()) {
119                 this.transaction.commit();
120             }
121         } catch (final Exception e) {
122             if (this.transaction != null && this.transaction.isActive()) {
123                 this.transaction.rollback();
124             }
125         } finally {
126             this.transaction = null;
127             try {
128                 if (this.entityManager != null && this.entityManager.isOpen()) {
129                     this.entityManager.close();
130                 }
131             } catch (final Exception e) {
132                 logWarn("Failed to close entity manager while logging event or flushing buffer", e);
133                 closed = false;
134             } finally {
135                 this.entityManager = null;
136             }
137         }
138         return closed;
139     }
140 
141     /**
142      * Creates a JPA manager for use within the {@link JpaAppender}, or returns a suitable one if it already exists.
143      *
144      * @param name The name of the manager, which should include connection details, entity class name, etc.
145      * @param bufferSize The size of the log event buffer.
146      * @param entityClass The fully-qualified class name of the {@link AbstractLogEventWrapperEntity} concrete
147      *                    implementation.
148      * @param entityConstructor The one-arg {@link LogEvent} constructor for the concrete entity class.
149      * @param persistenceUnitName The name of the JPA persistence unit that should be used for persisting log events.
150      * @return a new or existing JPA manager as applicable.
151      */
152     public static JpaDatabaseManager getJPADatabaseManager(final String name, final int bufferSize,
153                                                            final Class<? extends AbstractLogEventWrapperEntity>
154                                                                    entityClass,
155                                                            final Constructor<? extends AbstractLogEventWrapperEntity>
156                                                                    entityConstructor,
157                                                            final String persistenceUnitName) {
158 
159         return AbstractDatabaseManager.getManager(
160                 name, new FactoryData(bufferSize, entityClass, entityConstructor, persistenceUnitName), FACTORY
161         );
162     }
163 
164     /**
165      * Encapsulates data that {@link JPADatabaseManagerFactory} uses to create managers.
166      */
167     private static final class FactoryData extends AbstractDatabaseManager.AbstractFactoryData {
168         private final Class<? extends AbstractLogEventWrapperEntity> entityClass;
169         private final Constructor<? extends AbstractLogEventWrapperEntity> entityConstructor;
170         private final String persistenceUnitName;
171 
172         protected FactoryData(final int bufferSize, final Class<? extends AbstractLogEventWrapperEntity> entityClass,
173                               final Constructor<? extends AbstractLogEventWrapperEntity> entityConstructor,
174                               final String persistenceUnitName) {
175             super(bufferSize, null);
176 
177             this.entityClass = entityClass;
178             this.entityConstructor = entityConstructor;
179             this.persistenceUnitName = persistenceUnitName;
180         }
181     }
182 
183     /**
184      * Creates managers.
185      */
186     private static final class JPADatabaseManagerFactory implements ManagerFactory<JpaDatabaseManager, FactoryData> {
187         @Override
188         public JpaDatabaseManager createManager(final String name, final FactoryData data) {
189             return new JpaDatabaseManager(
190                     name, data.getBufferSize(), data.entityClass, data.entityConstructor, data.persistenceUnitName
191             );
192         }
193     }
194 }