com.google.enterprise.connector.util.database

Class DatabaseConnectionPool

java.lang.Object

com.google.enterprise.connector.util.database.DatabaseConnectionPool

public class DatabaseConnectionPool
extends java.lang.Object

A pool of JDBC database Connections. In certain JDBC implementations, database Connections may be expensive and time-consuming to open. This pool maintains a LIFO stack of open Connections in an attempt to re-use existing Connections to the database.

This class requires a JDBC driver that supports the isValid method of java.sql.Connection, part of the JDBC 4.0 specification in Java 6.

Since:

2.8

Constructor Summary

Constructors

Constructor and Description
DatabaseConnectionPool(javax.sql.DataSource dataSource) Constructs a pool to hold cached Connections to the suppied JDBC DataSource.

Method Summary

Modifier and Type	Method and Description
void	closeConnections() Empties the connection pool, closing all its Connections.
java.sql.Connection	getConnection() Returns a Connection from the connection pool.
javax.sql.DataSource	getDataSource() Returns the JDBC DataSource that owns these Connections.
void	releaseConnection(java.sql.Connection connection) Releases a Connection, returning it to the connection pool for later re-use.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DatabaseConnectionPool

public DatabaseConnectionPool(javax.sql.DataSource dataSource)

Constructs a pool to hold cached Connections to the suppied JDBC DataSource. The pool is initially empty.

Parameters:

dataSource - a JDBC DataSource

Method Detail

getDataSource

public javax.sql.DataSource getDataSource()

Returns the JDBC DataSource that owns these Connections.

Returns:

the connection pool's DataSource

getConnection

public java.sql.Connection getConnection()
                                  throws java.sql.SQLException

Returns a Connection from the connection pool. If the pool is empty, a new Connection is obtained from the DataSource.

Returns:

a Connection to the DataSource

Throws:

java.sql.SQLException - if a Connection cannot be obtained

releaseConnection

public void releaseConnection(java.sql.Connection connection)

Releases a Connection, returning it to the connection pool for later re-use.

Parameters:

connection - a Connection to to return to the pool

closeConnections

public void closeConnections()

Empties the connection pool, closing all its Connections.