+/*
+ * Copyright 2005-2010 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
package org.wamblee.support.persistence;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
import javax.sql.DataSource;
+import junit.framework.Assert;
+
import org.apache.commons.dbcp.ConnectionFactory;
import org.apache.commons.dbcp.DriverManagerConnectionFactory;
import org.apache.commons.dbcp.PoolableConnectionFactory;
import org.apache.commons.dbcp.PoolingDataSource;
import org.apache.commons.pool.impl.GenericObjectPool;
+/**
+ * Abstract database class providing the creation of the datasource,
+ * preventing duplicate starts of the same database, and checking
+ * for connection leaks when the database is stopped.
+ *
+ * @author Erik Brakkee
+ *
+ */
public abstract class AbstractDatabase implements Database {
- private static final int CONNECTION_POOL_SIZE = 16;
-
- private DataSource itsDataSource;
-
- private boolean started;
-
- protected AbstractDatabase() {
- started = false;
- }
-
- protected abstract void doStart();
-
- protected abstract void doStop();
-
- /**
- * This method must be called from the start method.
- */
- protected final void createDataSource() {
- GenericObjectPool connectionPool = new GenericObjectPool(null);
- connectionPool.setMaxActive(CONNECTION_POOL_SIZE);
- ConnectionFactory connectionFactory = new DriverManagerConnectionFactory(getJdbcUrl(), getUsername(), getPassword());
- // The following line must be kept in although it does not appear to be used, the constructor regsiters the
- // constructed object at the connection pool.
- PoolableConnectionFactory poolableConnectionFactory = new PoolableConnectionFactory(connectionFactory,connectionPool,null,null,false,true);
- itsDataSource = new PoolingDataSource(connectionPool);
- }
-
-
- /// BELOW THIS LINE IS NOT OF INTEREST TO SUBCLASSES.
-
- public final DataSource start() {
- if ( started ) {
- throw new RuntimeException("Database already started");
- }
- started = true;
- doStart();
- return getDatasource();
- }
-
- public final void stop() {
- if ( ! started ) {
- return; // nothing to do.
- }
- started = false;
- doStop();
- }
-
- private final DataSource getDatasource() {
- if ( !started) {
- throw new RuntimeException("Database is not started!");
- }
- return itsDataSource;
- }
-
- protected String getProperty(String aName) {
- String value = System.getProperty(aName);
- if ( value != null ) {
- return value;
- }
- value = System.getenv(aName);
- if ( value != null ) {
- return value;
- }
- throw new RuntimeException("This class expects the '" + aName + "' property to be set");
- }
+
+ /**
+ * Set this system property to a non-null value to ignore connection leaks
+ * when {@link #stop()} is called.
+ */
+ private static final String IGNORE_CONNECTION_LEAK_PROPERTY = "org.wamblee.database.ignoreconnectionleaks";
+
+ private static final Logger LOGGER = Logger
+ .getLogger(AbstractDatabase.class.getName());
+
+ private static final int CONNECTION_POOL_SIZE = 16;
+
+ private DataSource itsDataSource;
+
+ private GenericObjectPool connectionPool;
+
+ private boolean started;
+
+ /**
+ * Constructs the database.
+ */
+ protected AbstractDatabase() {
+ started = false;
+ }
+
+ /**
+ * To be implemented by subclasses to start the database.
+ */
+ protected abstract void doStart();
+
+ /**
+ * To be implemented by subclasses to stop the database.
+ */
+ protected abstract void doStop();
+
+ /**
+ * This method must be called from the start method.
+ */
+ protected final void createDataSource() {
+ connectionPool = new GenericObjectPool(null);
+ connectionPool.setMaxActive(CONNECTION_POOL_SIZE);
+ ConnectionFactory connectionFactory = new DriverManagerConnectionFactory(
+ getJdbcUrl(), getUsername(), getPassword());
+ // The following line must be kept in although it does not appear to be
+ // used, the constructor regsiters the
+ // constructed object at the connection pool.
+ PoolableConnectionFactory poolableConnectionFactory = new PoolableConnectionFactory(
+ connectionFactory, connectionPool, null, null, false, true);
+ ingoredVariable(poolableConnectionFactory);
+ itsDataSource = new PoolingDataSource(connectionPool);
+ }
+
+ @Override
+ public int getActiveConnections() {
+ return connectionPool.getNumActive();
+ }
+
+ private static void ingoredVariable(PoolableConnectionFactory aFactory) {
+ // Empty
+ }
+
+ // / BELOW THIS LINE IS NOT OF INTEREST TO SUBCLASSES.
+
+ /**
+ * Starts the database.
+ */
+ public final DataSource start() {
+ if (started) {
+ throw new RuntimeException("Database already started");
+ }
+ started = true;
+ doStart();
+ return getDatasource();
+ }
+
+ /**
+ * Stops the database and tests for connection leaks.
+ * In cast the system property with the name given by {@link #IGNORE_CONNECTION_LEAK_PROPERTY}
+ * is set then the connection leaks are not checked.
+ */
+ public final void stop() {
+ if (!started) {
+ return; // nothing to do.
+ }
+ started = false;
+ try {
+ if (connectionPool.getNumActive() > 0) {
+ String msg = "JDBC connection pool still has " +
+ connectionPool.getNumActive() +
+ " active connection(s), this is a potential resource leak in the code\n";
+ // backdoor to ignore connection leaks. Use this system property only if you
+ // can safely ignore the connection leaks.
+ if (System.getProperty(IGNORE_CONNECTION_LEAK_PROPERTY) == null) {
+ Assert.fail(msg);
+ }
+ }
+ connectionPool.close();
+ connectionPool.close();
+ } catch (Exception e) {
+ LOGGER.log(Level.WARNING, "Could not close pool", e);
+ }
+ doStop();
+ }
+
+ private final DataSource getDatasource() {
+ if (!started) {
+ throw new RuntimeException("Database is not started!");
+ }
+ return itsDataSource;
+ }
+
+ protected String getProperty(String aName) {
+ String value = System.getProperty(aName);
+ if (value != null) {
+ return value;
+ }
+ value = System.getenv(aName);
+ if (value != null) {
+ return value;
+ }
+ throw new RuntimeException("This class expects the '" + aName +
+ "' property to be set");
+ }
}
git://wamblee.org / utils / blobdiff