Added ping to connection validation check.

Closing connections at server shutdown.

src/de/diddiz/LogBlock/LogBlock.java

@@ -74,7 +74,7 @@ public class LogBlock extends JavaPlugin
 			return;
 		}
 		try {
-			pool = new ConnectionPool("com.mysql.jdbc.Driver", config.url, config.user, config.password);
+			pool = new ConnectionPool(config.url, config.user, config.password);
 			final Connection conn = getConnection();
 			conn.close();
 		} catch (final Exception ex) {
@@ -159,6 +159,8 @@ public class LogBlock extends JavaPlugin
 				thread.run();
 			}
 		}
+		if (pool != null)
+			pool.closeConnections();
 		log.info("LogBlock disabled.");
 	}
 
@@ -527,7 +529,7 @@ public class LogBlock extends JavaPlugin
 
 	public Connection getConnection() {
 		try {
-			return pool.connect(ConnectionPool.URL_PREFIX, null);
+			return pool.getConnection();
 		} catch (final SQLException ex) {
 			log.log(Level.SEVERE, "[LogBlock] Error while fetching connection", ex);
 			return null;

src/de/diddiz/util/ConnectionPool.java

@@ -20,11 +20,10 @@ import java.sql.CallableStatement;
 import java.sql.Clob;
 import java.sql.Connection;
 import java.sql.DatabaseMetaData;
-import java.sql.Driver;
 import java.sql.DriverManager;
-import java.sql.DriverPropertyInfo;
 import java.sql.NClob;
 import java.sql.PreparedStatement;
+import java.sql.ResultSet;
 import java.sql.SQLClientInfoException;
 import java.sql.SQLException;
 import java.sql.SQLWarning;
@@ -37,48 +36,80 @@ import java.util.Map;
 import java.util.Properties;
 import java.util.Vector;
 
-public class ConnectionPool implements Driver {
+public class ConnectionPool {
-	public static final String URL_PREFIX = "jdbc:jdc:";
+	private final Vector<JDCConnection> connections;
-	private static final int MAJOR_VERSION = 1;
+	private final String url, user, password;
-	private static final int MINOR_VERSION = 0;
+	private final long timeout = 60000;
-	private final ConnectionService pool;
+	private final ConnectionReaper reaper;
+	private final int poolsize = 10;
 
-	public ConnectionPool(String driver, String url, String user, String password) throws ClassNotFoundException, InstantiationException, IllegalAccessException, SQLException {
+	public ConnectionPool(String url, String user, String password) throws ClassNotFoundException {
-		DriverManager.registerDriver(this);
+		Class.forName("com.mysql.jdbc.Driver");
-		Class.forName(driver).newInstance();
+		this.url = url;
-		pool = new ConnectionService(url, user, password);
+		this.user = user;
+		this.password = password;
+		connections = new Vector<JDCConnection>(poolsize);
+		reaper = new ConnectionReaper();
+		reaper.start();
 	}
 
-	@Override
+	public synchronized Connection getConnection() throws SQLException {
-	public Connection connect(String url, Properties props) throws SQLException {
+		JDCConnection c;
-		if (!url.startsWith(URL_PREFIX))
+		for (int i = 0; i < connections.size(); i++) {
-			return null;
+			c = connections.elementAt(i);
-		return pool.getConnection();
+			if (c.lease()) {
+				if (c.validate())
+					return c;
+				else {
+					c.terminate();
+					removeConnection(c);
+				}
+			}
+		}
+		c = new JDCConnection(DriverManager.getConnection(url, user, password));
+		c.lease();
+		if (!c.validate()) {
+			c.terminate();
+			throw new SQLException("Failed to validate a brand new connection");
+		}
+		connections.addElement(c);
+		return c;
 	}
 
-	@Override
+	private synchronized void reapConnections() {
-	public boolean acceptsURL(String url) {
+		final long stale = System.currentTimeMillis() - timeout;
-		return url.startsWith(URL_PREFIX);
+		final Enumeration<JDCConnection> connlist = connections.elements();
+		while (connlist != null && connlist.hasMoreElements()) {
+			final JDCConnection conn = connlist.nextElement();
+			if (conn.inUse() && stale > conn.getLastUse() && !conn.validate())
+				removeConnection(conn);
+		}
 	}
 
-	@Override
+	public synchronized void closeConnections() {
-	public int getMajorVersion() {
+		final Enumeration<JDCConnection> connlist = connections.elements();
-		return MAJOR_VERSION;
+		while (connlist != null && connlist.hasMoreElements()) {
+			final JDCConnection conn = connlist.nextElement();
+			conn.terminate();
+			removeConnection(conn);
+		}
 	}
 
-	@Override
+	private synchronized void removeConnection(JDCConnection conn) {
-	public int getMinorVersion() {
+		connections.removeElement(conn);
-		return MINOR_VERSION;
 	}
 
-	@Override
+	private class ConnectionReaper extends Thread
-	public DriverPropertyInfo[] getPropertyInfo(String str, Properties props) {
+	{
-		return new DriverPropertyInfo[0];
+		@Override
-	}
+		public void run() {
-
+			while (true) {
-	@Override
+				try {
-	public boolean jdbcCompliant() {
+					Thread.sleep(300000);
-		return false;
+				} catch (final InterruptedException e) {}
+				reapConnections();
+			}
+		}
 	}
 
 	private class JDCConnection implements Connection
@@ -93,6 +124,12 @@ public class ConnectionPool implements Driver {
 			timestamp = 0;
 		}
 
+		public void terminate() {
+			try {
+				conn.close();
+			} catch (SQLException ex) {}
+		}
+
 		public synchronized boolean lease() {
 			if (inuse) {
 				return false;
@@ -104,12 +141,24 @@ public class ConnectionPool implements Driver {
 		}
 
 		public boolean validate() {
+			Statement state = null;
+			ResultSet rs = null;
 			try {
 				conn.getMetaData();
-			} catch (final Exception e) {
+				state = conn.createStatement();
-				return false;
+				rs = state.executeQuery("/* ping */");
+				if (rs.next() && rs.getInt(1) == 1)
+					return true;
+			} catch (final SQLException ex) {
+			} finally {
+				try {
+					if (rs != null)
+						rs.close();
+					if (state != null)
+						state.close();
+				} catch (final SQLException ex) {}
 			}
-			return true;
+			return false;
 		}
 
 		public boolean inUse() {
@@ -122,10 +171,6 @@ public class ConnectionPool implements Driver {
 
 		@Override
 		public void close() {
-			expireLease();
-		}
-
-		protected void expireLease() {
 			inuse = false;
 		}
 
@@ -363,85 +408,4 @@ public class ConnectionPool implements Driver {
 			return null;
 		}
 	}
-
-	public class ConnectionService
-	{
-		private final Vector<JDCConnection> connections;
-		private final String url, user, password;
-		final private long timeout = 60000;
-		private final ConnectionReaper reaper;
-		final private int poolsize = 10;
-
-		public ConnectionService(String url, String user, String password) {
-			this.url = url;
-			this.user = user;
-			this.password = password;
-			connections = new Vector<JDCConnection>(poolsize);
-			reaper = new ConnectionReaper(this);
-			reaper.start();
-		}
-
-		public synchronized void reapConnections() {
-			final long stale = System.currentTimeMillis() - timeout;
-			final Enumeration<JDCConnection> connlist = connections.elements();
-			while (connlist != null && connlist.hasMoreElements()) {
-				final JDCConnection conn = connlist.nextElement();
-				if (conn.inUse() && stale > conn.getLastUse() && !conn.validate())
-					removeConnection(conn);
-			}
-		}
-
-		public synchronized void closeConnections() {
-			final Enumeration<JDCConnection> connlist = connections.elements();
-			while (connlist != null && connlist.hasMoreElements()) {
-				final JDCConnection conn = connlist.nextElement();
-				removeConnection(conn);
-			}
-		}
-
-		private synchronized void removeConnection(JDCConnection conn) {
-			connections.removeElement(conn);
-		}
-
-		public synchronized Connection getConnection() throws SQLException {
-			JDCConnection c;
-			for (int i = 0; i < connections.size(); i++) {
-				c = connections.elementAt(i);
-				if (c.lease()) {
-					if (c.validate())
-						return c;
-					else
-						removeConnection(c);
-				}
-			}
-			c = new JDCConnection(DriverManager.getConnection(url, user, password));
-			c.lease();
-			connections.addElement(c);
-			return c;
-		}
-
-		public synchronized void returnConnection(JDCConnection conn) {
-			conn.expireLease();
-		}
-	}
-
-	class ConnectionReaper extends Thread
-	{
-		private final ConnectionService pool;
-		private final long delay = 300000;
-
-		ConnectionReaper(ConnectionService pool) {
-			this.pool = pool;
-		}
-
-		@Override
-		public void run() {
-			while (true) {
-				try {
-					Thread.sleep(delay);
-				} catch (final InterruptedException e) {}
-				pool.reapConnections();
-			}
-		}
-	}
 }