Examples of javax.sql.PooledConnection

javax.sql.PooledConnection
An interface which provides facilities for handling connections to a database which are pooled.
Typically, a PooledConnection is recycled when it is no longer required by an application, rather than being closed and discarded. The reason for treating connections in this way is that it can be an expensive process both to establish a connection to a database and to destroy the connection. Reusing connections through a pool is a way of improving system performance and reducing overhead.
It is not intended that an application use the PooledConnection interface directly. The PooledConnection interface is intended for use by a component called a Connection Pool Manager, typically part of the infrastructure that supports use of the database by applications.
Applications obtain connections to the database by calling the DataSource.getConnection method. Under the covers, the Connection Pool Manager will get a PooledConnection object from its connection pool and passes back a Connection object that wraps or references the PooledConnection object. A new PooledConnection object will only be created if the pool is empty.
When the application is finished using a PooledConnection, the application calls the Connection.close method. The Connection Pool Manager is notified via a ConnectionEvent from the Connection that this has happened (the Pool Manager registers itself with the Connection before the Connection is given to the application). The Pool Manager removes the underlying PooledConnection object from the Connection and returns it to the pool for reuse - the PooledConnection is thus recycled rather than being destroyed.
The connection to the database represented by the PooledConnection is kept open until the PooledConnection object itself is deactivated by the Connection Pool Manager, which calls the PooledConnection.close method. This is typically done if there are too many inactive connections in the pool, if the PooledConnection encounters a problem that makes it unusable or if the whole system is being shut down.

    /**
     * Closes the PooledConnection and stops listening for events from it.
     */
    public void destroyObject(Object key, Object obj) throws Exception {
        if (obj instanceof PooledConnectionAndInfo) {
            PooledConnection pc = ((PooledConnectionAndInfo)obj).getPooledConnection();
            pc.removeConnectionEventListener(this);
            pcMap.remove(pc);
            pc.close(); 
        }
    }

View Full Code Here

     * @return true if validation suceeds
     */
    public boolean validateObject(Object key, Object obj) {
        boolean valid = false;
        if (obj instanceof PooledConnectionAndInfo) {
            PooledConnection pconn =
                ((PooledConnectionAndInfo)obj).getPooledConnection();
            String query = _validationQuery;
            if (null != query) {
                Connection conn = null;
                Statement stmt = null;
                ResultSet rset = null;
                // logical Connection from the PooledConnection must be closed
                // before another one can be requested and closing it will
                // generate an event. Keep track so we know not to return
                // the PooledConnection
                validatingMap.put(pconn, null);
                try {
                    conn = pconn.getConnection();
                    stmt = conn.createStatement();
                    rset = stmt.executeQuery(query);
                    if (rset.next()) {
                        valid = true;
                    } else {

View Full Code Here

     * method came from a PooledConnection, and the user calls the close()
     * method of this connection object. What we need to do here is to
     * release this PooledConnection from our pool...
     */
    public void connectionClosed(ConnectionEvent event) {
        PooledConnection pc = (PooledConnection)event.getSource();
        // if this event occurred because we were validating, or if this
        // connection has been marked for removal, ignore it
        // otherwise return the connection to the pool.
        if (!validatingMap.containsKey(pc)) {
            PooledConnectionAndInfo info =
                (PooledConnectionAndInfo) pcMap.get(pc);
            if (info == null) {
                throw new IllegalStateException(NO_KEY_MESSAGE);
            }
            try {
                _pool.returnObject(info.getUserPassKey(), info);
            } catch (Exception e) {
                System.err.println("CLOSING DOWN CONNECTION AS IT COULD " +
                "NOT BE RETURNED TO THE POOL");
                pc.removeConnectionEventListener(this);
                try {
                    _pool.invalidateObject(info.getUserPassKey(), info);
                } catch (Exception e3) {
                    System.err.println("EXCEPTION WHILE DESTROYING OBJECT " +
                            info);

View Full Code Here

    /**
     * If a fatal error occurs, close the underlying physical connection so as
     * not to be returned in the future
     */
    public void connectionErrorOccurred(ConnectionEvent event) {
        PooledConnection pc = (PooledConnection)event.getSource();
        if (null != event.getSQLException()) {
            System.err
                .println("CLOSING DOWN CONNECTION DUE TO INTERNAL ERROR (" +
                         event.getSQLException() + ")");
        }
        pc.removeConnectionEventListener(this);


        PooledConnectionAndInfo info = (PooledConnectionAndInfo) pcMap.get(pc);
        if (info == null) {
            throw new IllegalStateException(NO_KEY_MESSAGE);
        }

View Full Code Here

                    + " doesn't implement javax.sql.ConnectionPoolDataSource");
            }
        }
        
        // try to get a connection with the supplied username/password
        PooledConnection conn = null;
        try {
            if (username != null) {
                conn = cpds.getPooledConnection(username, password);
            }
            else {
                conn = cpds.getPooledConnection();
            }
            if (conn == null) {
                throw new SQLException(
                    "Cannot connect using the supplied username/password");
            }
        }
        finally {
            if (conn != null) {
                try {
                    conn.close();
                }
                catch (SQLException e) {
                    // at least we could connect
                }
            }

View Full Code Here

     }


    public synchronized Object makeObject() {
        Object obj;
        try {
            PooledConnection pc = null;
            if (_username == null) {
                pc = _cpds.getPooledConnection();
            } else {
                pc = _cpds.getPooledConnection(_username, _password);
            }


            if (pc == null) {
                throw new IllegalStateException("Connection pool data source returned null from getPooledConnection");
            }


            // should we add this object as a listener or the pool.
            // consider the validateObject method in decision
            pc.addConnectionEventListener(this);
            obj = new PooledConnectionAndInfo(pc, _username, _password);
            pcMap.put(pc, obj);
        } catch (SQLException e) {
            throw new RuntimeException(e.getMessage());
        }

View Full Code Here

    /**
     * Closes the PooledConnection and stops listening for events from it.
     */
    public void destroyObject(Object obj) throws Exception {
        if (obj instanceof PooledConnectionAndInfo) {
            PooledConnection pc = ((PooledConnectionAndInfo)obj).getPooledConnection();
            pc.removeConnectionEventListener(this);
            pcMap.remove(pc);
            pc.close(); 
        }
    }

View Full Code Here

    }


    public boolean validateObject(Object obj) {
        boolean valid = false;
        if (obj instanceof PooledConnectionAndInfo) {
            PooledConnection pconn =
                ((PooledConnectionAndInfo) obj).getPooledConnection();
            String query = _validationQuery;
            if (null != query) {
                Connection conn = null;
                Statement stmt = null;
                ResultSet rset = null;
                // logical Connection from the PooledConnection must be closed
                // before another one can be requested and closing it will
                // generate an event. Keep track so we know not to return
                // the PooledConnection
                validatingMap.put(pconn, null);
                try {
                    conn = pconn.getConnection();
                    stmt = conn.createStatement();
                    rset = stmt.executeQuery(query);
                    if (rset.next()) {
                        valid = true;
                    } else {

View Full Code Here

     * method came from a PooledConnection, and the user calls the close()
     * method of this connection object. What we need to do here is to
     * release this PooledConnection from our pool...
     */
    public void connectionClosed(ConnectionEvent event) {
        PooledConnection pc = (PooledConnection) event.getSource();
        // if this event occured becase we were validating, ignore it
        // otherwise return the connection to the pool.
        if (!validatingMap.containsKey(pc)) {
            Object info = pcMap.get(pc);
            if (info == null) {
                throw new IllegalStateException(NO_KEY_MESSAGE);
            }


            try {
                _pool.returnObject(info);
            } catch (Exception e) {
                System.err.println("CLOSING DOWN CONNECTION AS IT COULD "
                        + "NOT BE RETURNED TO THE POOL");
                pc.removeConnectionEventListener(this);
                try {
                    destroyObject(info);
                } catch (Exception e2) {
                    System.err.println("EXCEPTION WHILE DESTROYING OBJECT "
                            + info);

View Full Code Here

    /**
     * If a fatal error occurs, close the underlying physical connection so as
     * not to be returned in the future
     */
    public void connectionErrorOccurred(ConnectionEvent event) {
        PooledConnection pc = (PooledConnection)event.getSource();
        if (null != event.getSQLException()) {
            System.err.println(
                    "CLOSING DOWN CONNECTION DUE TO INTERNAL ERROR ("
                    + event.getSQLException() + ")");
        }
        pc.removeConnectionEventListener(this);


        Object info = pcMap.get(pc);
        if (info == null) {
            throw new IllegalStateException(NO_KEY_MESSAGE);
        }

View Full Code Here

0 1 2 3 4 5 6 7 8 9

TOP

Related Classes of javax.sql.PooledConnection

co.cask.cdap.common.db.DBConnectionPoolManager

co.cask.cdap.common.db.DBConnectionPoolManager$PoolConnectionEventListener

com.alibaba.druid.bvt.pool.DruidDataSourceTest_getPooledConnection

com.alibaba.druid.bvt.pool.DruidDataSourceTest_testOnBorrowFailed

com.alibaba.druid.bvt.pool.DruidDataSourceTest_testOnWhileIdleFailed

com.alibaba.wasp.jdbcx.JdbcConnectionPool

com.atomikos.jdbc.ConnectionPool

com.atomikos.jdbc.SimpleDataSourceBean

com.caucho.sql.DriverConfig

com.caucho.sql.ManagedConnectionImpl

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.