Hi, What is the justification for this extra level?
Gary <div>-------- Original message --------</div><div>From: mattsic...@apache.org </div><div>Date:08/11/2014 22:04 (GMT-05:00) </div><div>To: comm...@logging.apache.org </div><div>Subject: svn commit: r1617397 - /logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/jdbc/JdbcDatabaseManager.java </div><div> </div>Author: mattsicker Date: Tue Aug 12 02:04:38 2014 New Revision: 1617397 URL: http://svn.apache.org/r1617397 Log: Singleton pattern Modified: logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/jdbc/JdbcDatabaseManager.java Modified: logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/jdbc/JdbcDatabaseManager.java URL: http://svn.apache.org/viewvc/logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/jdbc/JdbcDatabaseManager.java?rev=1617397&r1=1617396&r2=1617397&view=diff ============================================================================== --- logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/jdbc/JdbcDatabaseManager.java (original) +++ logging/log4j/log4j2/trunk/log4j-core/src/main/java/org/apache/logging/log4j/core/appender/db/jdbc/JdbcDatabaseManager.java Tue Aug 12 02:04:38 2014 @@ -36,7 +36,6 @@ import org.apache.logging.log4j.core.uti * An {@link AbstractDatabaseManager} implementation for relational databases accessed via JDBC. */ public final class JdbcDatabaseManager extends AbstractDatabaseManager { - private static final JDBCDatabaseManagerFactory FACTORY = new JDBCDatabaseManagerFactory(); private final List<Column> columns; private final ConnectionSource connectionSource; @@ -174,10 +173,19 @@ public final class JdbcDatabaseManager e final ColumnConfig[] columnConfigs) { return AbstractDatabaseManager.getManager( - name, new FactoryData(bufferSize, connectionSource, tableName, columnConfigs), FACTORY + name, new FactoryData(bufferSize, connectionSource, tableName, columnConfigs), getFactory() ); } + // the usual lazy singleton + private static class Holder { + private static final JDBCDatabaseManagerFactory INSTANCE = new JDBCDatabaseManagerFactory(); + } + + private static JDBCDatabaseManagerFactory getFactory() { + return Holder.INSTANCE; + } + /** * Encapsulates data that {@link JDBCDatabaseManagerFactory} uses to create managers. */
