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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.jdbc;
18  
19  import java.io.StringReader;
20  import java.sql.Connection;
21  import java.sql.DatabaseMetaData;
22  import java.sql.PreparedStatement;
23  import java.sql.SQLException;
24  import java.sql.Timestamp;
25  import java.util.ArrayList;
26  import java.util.List;
27  
28  import org.apache.logging.log4j.core.LogEvent;
29  import org.apache.logging.log4j.core.appender.AppenderLoggingException;
30  import org.apache.logging.log4j.core.appender.ManagerFactory;
31  import org.apache.logging.log4j.core.appender.db.AbstractDatabaseManager;
32  import org.apache.logging.log4j.core.layout.PatternLayout;
33  import org.apache.logging.log4j.core.util.Closer;
34  
35  /**
36   * An {@link AbstractDatabaseManager} implementation for relational databases accessed via JDBC.
37   */
38  public final class JdbcDatabaseManager extends AbstractDatabaseManager {
39  
40      private static final JdbcDatabaseManagerFactory INSTANCE = new JdbcDatabaseManagerFactory();
41  
42      private final List<Column> columns;
43      private final ConnectionSource connectionSource;
44      private final String sqlStatement;
45  
46      private Connection connection;
47      private PreparedStatement statement;
48      private boolean isBatchSupported;
49  
50      private JdbcDatabaseManager(final String name, final int bufferSize, final ConnectionSource connectionSource,
51                                  final String sqlStatement, final List<Column> columns) {
52          super(name, bufferSize);
53          this.connectionSource = connectionSource;
54          this.sqlStatement = sqlStatement;
55          this.columns = columns;
56      }
57  
58      @Override
59      protected void startupInternal() throws Exception {
60          this.connection = this.connectionSource.getConnection();
61          final DatabaseMetaData metaData = this.connection.getMetaData();
62          this.isBatchSupported = metaData.supportsBatchUpdates();
63          Closer.closeSilently(this.connection);
64      }
65  
66      @Override
67      protected void shutdownInternal() {
68          if (this.connection != null || this.statement != null) {
69              this.commitAndClose();
70          }
71      }
72  
73      @Override
74      protected void connectAndStart() {
75          try {
76              this.connection = this.connectionSource.getConnection();
77              this.connection.setAutoCommit(false);
78              this.statement = this.connection.prepareStatement(this.sqlStatement);
79          } catch (final SQLException e) {
80              throw new AppenderLoggingException(
81                      "Cannot write logging event or flush buffer; JDBC manager cannot connect to the database.", e
82              );
83          }
84      }
85  
86      @Override
87      protected void writeInternal(final LogEvent event) {
88          StringReader reader = null;
89          try {
90              if (!this.isRunning() || this.connection == null || this.connection.isClosed() || this.statement == null
91                      || this.statement.isClosed()) {
92                  throw new AppenderLoggingException(
93                          "Cannot write logging event; JDBC manager not connected to the database.");
94              }
95  
96              int i = 1;
97              for (final Column column : this.columns) {
98                  if (column.isEventTimestamp) {
99                      this.statement.setTimestamp(i++, new Timestamp(event.getTimeMillis()));
100                 } else {
101                     if (column.isClob) {
102                         reader = new StringReader(column.layout.toSerializable(event));
103                         if (column.isUnicode) {
104                             this.statement.setNClob(i++, reader);
105                         } else {
106                             this.statement.setClob(i++, reader);
107                         }
108                     } else {
109                         if (column.isUnicode) {
110                             this.statement.setNString(i++, column.layout.toSerializable(event));
111                         } else {
112                             this.statement.setString(i++, column.layout.toSerializable(event));
113                         }
114                     }
115                 }
116             }
117 
118             if (this.isBatchSupported) {
119                 this.statement.addBatch();
120             } else if (this.statement.executeUpdate() == 0) {
121                 throw new AppenderLoggingException(
122                         "No records inserted in database table for log event in JDBC manager.");
123             }
124         } catch (final SQLException e) {
125             throw new AppenderLoggingException("Failed to insert record for log event in JDBC manager: " +
126                     e.getMessage(), e);
127         } finally {
128             Closer.closeSilently(reader);
129         }
130     }
131 
132     @Override
133     protected void commitAndClose() {
134         try {
135             if (this.connection != null && !this.connection.isClosed()) {
136                 if (this.isBatchSupported) {
137                     this.statement.executeBatch();
138                 }
139                 this.connection.commit();
140             }
141         } catch (final SQLException e) {
142             throw new AppenderLoggingException("Failed to commit transaction logging event or flushing buffer.", e);
143         } finally {
144             try {
145                 Closer.close(this.statement);
146             } catch (final Exception e) {
147                 LOGGER.warn("Failed to close SQL statement logging event or flushing buffer.", e);
148             } finally {
149                 this.statement = null;
150             }
151 
152             try {
153                 Closer.close(this.connection);
154             } catch (final Exception e) {
155                 LOGGER.warn("Failed to close database connection logging event or flushing buffer.", e);
156             } finally {
157                 this.connection = null;
158             }
159         }
160     }
161 
162     /**
163      * Creates a JDBC manager for use within the {@link JdbcAppender}, or returns a suitable one if it already exists.
164      *
165      * @param name The name of the manager, which should include connection details and hashed passwords where possible.
166      * @param bufferSize The size of the log event buffer.
167      * @param connectionSource The source for connections to the database.
168      * @param tableName The name of the database table to insert log events into.
169      * @param columnConfigs Configuration information about the log table columns.
170      * @return a new or existing JDBC manager as applicable.
171      */
172     public static JdbcDatabaseManager getJDBCDatabaseManager(final String name, final int bufferSize,
173                                                              final ConnectionSource connectionSource,
174                                                              final String tableName,
175                                                              final ColumnConfig[] columnConfigs) {
176 
177         return AbstractDatabaseManager.getManager(
178                 name, new FactoryData(bufferSize, connectionSource, tableName, columnConfigs), getFactory()
179         );
180     }
181 
182     private static JdbcDatabaseManagerFactory getFactory() {
183         return INSTANCE;
184     }
185 
186     /**
187      * Encapsulates data that {@link JdbcDatabaseManagerFactory} uses to create managers.
188      */
189     private static final class FactoryData extends AbstractDatabaseManager.AbstractFactoryData {
190         private final ColumnConfig[] columnConfigs;
191         private final ConnectionSource connectionSource;
192         private final String tableName;
193 
194         protected FactoryData(final int bufferSize, final ConnectionSource connectionSource, final String tableName,
195                               final ColumnConfig[] columnConfigs) {
196             super(bufferSize);
197             this.connectionSource = connectionSource;
198             this.tableName = tableName;
199             this.columnConfigs = columnConfigs;
200         }
201     }
202 
203     /**
204      * Creates managers.
205      */
206     private static final class JdbcDatabaseManagerFactory implements ManagerFactory<JdbcDatabaseManager, FactoryData> {
207         @Override
208         public JdbcDatabaseManager createManager(final String name, final FactoryData data) {
209             final StringBuilder columnPart = new StringBuilder();
210             final StringBuilder valuePart = new StringBuilder();
211             final List<Column> columns = new ArrayList<Column>();
212             int i = 0;
213             for (final ColumnConfig config : data.columnConfigs) {
214                 if (i++ > 0) {
215                     columnPart.append(',');
216                     valuePart.append(',');
217                 }
218 
219                 columnPart.append(config.getColumnName());
220 
221                 if (config.getLiteralValue() != null) {
222                     valuePart.append(config.getLiteralValue());
223                 } else {
224                     columns.add(new Column(
225                             config.getLayout(), config.isEventTimestamp(), config.isUnicode(), config.isClob()
226                     ));
227                     valuePart.append('?');
228                 }
229             }
230 
231             final String sqlStatement = "INSERT INTO " + data.tableName + " (" + columnPart + ") VALUES (" +
232                     valuePart + ')';
233 
234             return new JdbcDatabaseManager(name, data.getBufferSize(), data.connectionSource, sqlStatement, columns);
235         }
236     }
237 
238     /**
239      * Encapsulates information about a database column and how to persist data to it.
240      */
241     private static final class Column {
242         private final PatternLayout layout;
243         private final boolean isEventTimestamp;
244         private final boolean isUnicode;
245         private final boolean isClob;
246 
247         private Column(final PatternLayout layout, final boolean isEventDate, final boolean isUnicode,
248                        final boolean isClob) {
249             this.layout = layout;
250             this.isEventTimestamp = isEventDate;
251             this.isUnicode = isUnicode;
252             this.isClob = isClob;
253         }
254     }
255 }