com.knowgate.jdc

Class JDCConnectionPool

java.lang.Object

com.knowgate.jdc.JDCConnectionPool

All Implemented Interfaces:

com.knowgate.storage.DataSource, javax.sql.CommonDataSource, javax.sql.ConnectionPoolDataSource

public final class JDCConnectionPool
extends java.lang.Object
implements javax.sql.ConnectionPoolDataSource, com.knowgate.storage.DataSource

JDBC Connection Pool

Implementation of a standard JDBC connection pool.

Version:

7.0

Constructor Summary

Constructors

Constructor and Description
JDCConnectionPool()
JDCConnectionPool(java.lang.Object bind, java.lang.String url, java.lang.String user, java.lang.String password, int maxpoolsize, int maxconnections) Constructor This method sets a default login timeout of 20 seconds
JDCConnectionPool(java.lang.Object bind, java.lang.String url, java.lang.String user, java.lang.String password, int maxpoolsize, int maxconnections, int logintimeout) Constructor This method sets a default login timeout of 20 seconds
JDCConnectionPool(java.lang.Object bind, java.lang.String url, java.lang.String user, java.lang.String password, int maxpoolsize, int maxconnections, int logintimeout, long connectiontimeout) Constructor This method sets a default login timeout of 20 seconds
JDCConnectionPool(java.lang.String url, java.lang.String user, java.lang.String password) Constructor By default, maximum pool size is set to 32, maximum opened connections is 100, login timeout is 20 seconds, connection timeout is 5 minutes.
JDCConnectionPool(java.lang.String url, java.lang.String user, java.lang.String password, int maxpoolsize, int maxconnections) Constructor This method sets a default login timeout of 20 seconds
JDCConnectionPool(java.lang.String url, java.lang.String user, java.lang.String password, int maxpoolsize, int maxconnections, int logintimeout) Constructor

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close all connections and stop connection reaper
void	closeConnections() Close all connections from the pool regardless of their current state
int	closeStaledConnections() Close connections from the pool not used for a longer time
java.lang.String	dumpStatistics() Human readable usage statistics
JDCActivityInfo	getActivityInfo() Get information of current activity at database to which this pool is connected
JDCConnection[]	getAllConnections() Get an array with references to all pooled connections
JDCConnection	getConnection(java.lang.String sCaller) Get a connection from the pool
JDCConnection	getConnectionForPId(java.lang.String sPId) Get conenction for a server process identifier
javax.sql.DataSource	getDatabaseBinding() Get the DBbind object owner of this conenction pool
java.util.Map	getDBTablesMap()
com.knowgate.storage.Engine	getEngine()
int	getLoginTimeout() Get login timeout from java.sql.DriverManager
java.io.PrintWriter	getLogWriter() Get LogWriter from java.sql.DriverManager
int	getMaxPoolSize() Absolute maximum allowed for concurrent opened connections.
com.knowgate.storage.SchemaMetaData	getMetaData()
java.util.logging.Logger	getParentLogger() This method is added for compatibility with Java 7 and it is not implemented
javax.sql.PooledConnection	getPooledConnection() Get a connection from the pool
javax.sql.PooledConnection	getPooledConnection(java.lang.String sUser, java.lang.String sPasswd) Get a connection bypassing the pool and connection directly to the database with the given user and password
int	getPoolSize() Get prefered open connections limit Additional connections beyond PoolSize may be opened but they will closed inmediately after use and not pooled.
long	getReaperDaemonDelay() Delay betwwen connection reaper executions
long	getTimeout() Get staled connection threshold The default value is 600000ms (10 mins.)
boolean	isClosed()
boolean	isReadOnly()
void	open(java.lang.String url, java.lang.String user, java.lang.String password, boolean readonly) Open ConnectionPool By default, maximum pool size is set to 32, maximum opened connections is 100, login timeout is 20 seconds, connection timeout is 5 minutes.
com.knowgate.storage.Table	openTable(com.knowgate.storage.Record oRec)
com.knowgate.storage.Table	openTable(java.lang.String sName)
com.knowgate.storage.Table	openTable(java.lang.String sName, java.lang.String[] sIndexes)
void	returnConnection(JDCConnection conn) Return a connection to the pool
void	returnConnection(JDCConnection conn, java.lang.String sCaller) Return a connection to the pool
void	setLoginTimeout(int seconds) Set login timeout for java.sql.DriverManager
void	setLogWriter(java.io.PrintWriter printwrt) Set LogWriter for java.sql.DriverManager
void	setMaxPoolSize(int iMaxConnections) Set maximum concurrent open connections limit The default value is 100.
void	setPoolSize(int iPoolSize) Set prefered open connections limit Additional connections beyond PoolSize may be opened but they will closed inmediately after use and not pooled.
void	setReaperDaemonDelay(long lDelayMs) Set delay betwwen connection reaper executions (default value is 5 mins)
void	setTimeout(long miliseconds) Set staled connection threshold
int	size()

Methods inherited from class java.lang.Object

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

Constructor Detail

JDCConnectionPool

public JDCConnectionPool()

JDCConnectionPool

public JDCConnectionPool(java.lang.String url,
                 java.lang.String user,
                 java.lang.String password)
                  throws com.knowgate.storage.StorageException

Constructor By default, maximum pool size is set to 32, maximum opened connections is 100, login timeout is 20 seconds, connection timeout is 5 minutes.

Parameters:

url - JDBC URL string

user - Database user

password - Password for user

Throws:

com.knowgate.storage.StorageException

JDCConnectionPool

public JDCConnectionPool(java.lang.Object bind,
                 java.lang.String url,
                 java.lang.String user,
                 java.lang.String password,
                 int maxpoolsize,
                 int maxconnections,
                 int logintimeout,
                 long connectiontimeout)

Constructor

This method sets a default login timeout of 20 seconds

Parameters:

bind - DBBind owner of the connection pool (may be null)

url - JDBC URL string

user - Database user

password - Password for user

maxpoolsize - Maximum pool size

maxconnections - Maximum opened connections

connectiontimeout - Maximum time that a

logintimeout - Maximum time, in seconds, to wait for connection

Since:

v2.2

JDCConnectionPool

public JDCConnectionPool(java.lang.Object bind,
                 java.lang.String url,
                 java.lang.String user,
                 java.lang.String password,
                 int maxpoolsize,
                 int maxconnections,
                 int logintimeout)

Constructor

This method sets a default login timeout of 20 seconds

Parameters:

bind - DBBind owner of the connection pool (may be null)

url - JDBC URL string

user - Database user

password - Password for user

maxpoolsize - Maximum pool size

maxconnections - Maximum opened connections

logintimeout - Maximum time, in seconds, to wait for connection

Since:

v2.2

JDCConnectionPool

public JDCConnectionPool(java.lang.Object bind,
                 java.lang.String url,
                 java.lang.String user,
                 java.lang.String password,
                 int maxpoolsize,
                 int maxconnections)

Constructor

This method sets a default login timeout of 20 seconds

Parameters:

bind - DBBind owner of the connection pool (may be null)

url - JDBC URL string

user - Database user

password - Password for user

maxpoolsize - Maximum pool size (Default 32)

maxconnections - Maximum opened connections (Default 100)

JDCConnectionPool

public JDCConnectionPool(java.lang.String url,
                 java.lang.String user,
                 java.lang.String password,
                 int maxpoolsize,
                 int maxconnections,
                 int logintimeout)

Constructor

Parameters:

url - JDBC URL string

user - Database user

password - Password for user

maxpoolsize - Maximum pool size (Default 32)

maxconnections - Maximum opened connections (Default 100)

logintimeout - Maximum time, in seconds, to wait for connection

Since:

v2.2

JDCConnectionPool

public JDCConnectionPool(java.lang.String url,
                 java.lang.String user,
                 java.lang.String password,
                 int maxpoolsize,
                 int maxconnections)

Constructor

This method sets a default login timeout of 20 seconds

Parameters:

url - JDBC URL string

user - Database user

password - Password for user

maxpoolsize - Maximum pool size

maxconnections - Maximum opened connections

Method Detail

getEngine

public com.knowgate.storage.Engine getEngine()

Specified by:

getEngine in interface com.knowgate.storage.DataSource

Returns:

Engine.JDBCRDBMS

Since:

6.0

open

public void open(java.lang.String url,
        java.lang.String user,
        java.lang.String password,
        boolean readonly)
          throws com.knowgate.storage.StorageException

Open ConnectionPool

By default, maximum pool size is set to 32, maximum opened connections is 100, login timeout is 20 seconds, connection timeout is 5 minutes.

Specified by:

open in interface com.knowgate.storage.DataSource

Parameters:

url - JDBC URL string

user - Database user

password - Password for user

Throws:

com.knowgate.storage.StorageException

close

public void close()

Close all connections and stop connection reaper

Specified by:

close in interface com.knowgate.storage.DataSource

isClosed

public boolean isClosed()

Specified by:

isClosed in interface com.knowgate.storage.DataSource

getPoolSize

public int getPoolSize()

Get prefered open connections limit

Additional connections beyond PoolSize may be opened but they will closed inmediately after use and not pooled.
The default value is 32.

Returns:

open connections soft limit

setPoolSize

public void setPoolSize(int iPoolSize)

Set prefered open connections limit

Additional connections beyond PoolSize may be opened but they will closed inmediately after use and not pooled.
The default value is 32.
Connections not being used can only be in the pool for a maximum of five minutes.
After a connection is not used for over 5 minutes it will be closed so the actual pool size will eventually go down to zero after a period of inactivity.

Parameters:

iPoolSize - Maximum pooled connections

setMaxPoolSize

public void setMaxPoolSize(int iMaxConnections)

Set maximum concurrent open connections limit

The default value is 100.
If iMaxConnections is set to zero then the connection pool is effectively turned off and no pooling occurs.

Parameters:

iMaxConnections - Absolute maximum for opened connections

getMaxPoolSize

public int getMaxPoolSize()

Absolute maximum allowed for concurrent opened connections.

The default value is 100.

getLogWriter

public java.io.PrintWriter getLogWriter()
                                 throws java.sql.SQLException

Get LogWriter from java.sql.DriverManager

Specified by:

getLogWriter in interface javax.sql.CommonDataSource

Throws:

java.sql.SQLException

Since:

4.0

setLogWriter

public void setLogWriter(java.io.PrintWriter printwrt)
                  throws java.sql.SQLException

Set LogWriter for java.sql.DriverManager

Specified by:

setLogWriter in interface javax.sql.CommonDataSource

Throws:

java.sql.SQLException

Since:

4.0

getLoginTimeout

public int getLoginTimeout()
                    throws java.sql.SQLException

Get login timeout from java.sql.DriverManager

Specified by:

getLoginTimeout in interface javax.sql.CommonDataSource

Throws:

java.sql.SQLException

Since:

4.0

setLoginTimeout

public void setLoginTimeout(int seconds)
                     throws java.sql.SQLException

Set login timeout for java.sql.DriverManager

Specified by:

setLoginTimeout in interface javax.sql.CommonDataSource

Throws:

java.sql.SQLException

Since:

4.0

getTimeout

public long getTimeout()

Get staled connection threshold

The default value is 600000ms (10 mins.)
This implies that all database operations done using connections obtained from the pool must be completed before 10 minutes or else they can be closed by the connection reaper before their normal finish.

Returns:

The maximum amount of time in miliseconds that a JDCConnection can be opened and not used before considering it staled.

setTimeout

public void setTimeout(long miliseconds)
                throws java.lang.IllegalArgumentException

Set staled connection threshold

Parameters:

miliseconds - The maximum amount of time in miliseconds that a JDCConnection can be opened and not used before considering it staled.
Default value is 600000ms (10 mins.) Minimum value is 1000.

Throws:

java.lang.IllegalArgumentException - If miliseconds<1000

getReaperDaemonDelay

public long getReaperDaemonDelay()

Delay betwwen connection reaper executions

Returns:

long Number of miliseconds

Since:

3.0

setReaperDaemonDelay

public void setReaperDaemonDelay(long lDelayMs)
                          throws java.lang.IllegalArgumentException

Set delay betwwen connection reaper executions (default value is 5 mins)

Parameters:

lDelayMs - long Miliseconds

Throws:

java.lang.IllegalArgumentException - if lDelayMs is less than 1000

Since:

3.0

closeConnections

public void closeConnections()

Close all connections from the pool regardless of their current state

closeStaledConnections

public int closeStaledConnections()

Close connections from the pool not used for a longer time

Returns:

Count of staled connections closed

getAllConnections

public JDCConnection[] getAllConnections()

Get an array with references to all pooled connections

getDatabaseBinding

public javax.sql.DataSource getDatabaseBinding()

Get the DBbind object owner of this conenction pool

Returns:

DBBind instance or null if this connection pool has no owner

getConnection

public JDCConnection getConnection(java.lang.String sCaller)
                            throws java.sql.SQLException

Get a connection from the pool

Parameters:

sCaller - This is just an information parameter used for open/closed mismatch tracking and other benchmarking and statistical purposes.

Returns:

Opened JDCConnection

Throws:

java.sql.SQLException - If getMaxPoolSize() opened connections is reached an SQLException with SQLState="08004" will be raised upon calling getConnection().
Microsoft SQL Server: Connection reuse requires that SelectMethod=cursor was specified at connection string.

getPooledConnection

public javax.sql.PooledConnection getPooledConnection()
                                               throws java.sql.SQLException

Get a connection from the pool

Specified by:

getPooledConnection in interface javax.sql.ConnectionPoolDataSource

Returns:

Opened PooledConnection

Throws:

java.sql.SQLException - If getMaxPoolSize() opened connections is reached an SQLException with SQLState="08004" will be raised upon calling getConnection().
Microsoft SQL Server: Connection reuse requires that SelectMethod=cursor was specified at connection string.

Since:

4.0

getPooledConnection

public javax.sql.PooledConnection getPooledConnection(java.lang.String sUser,
                                             java.lang.String sPasswd)
                                               throws java.sql.SQLException

Get a connection bypassing the pool and connection directly to the database with the given user and password

Specified by:

getPooledConnection in interface javax.sql.ConnectionPoolDataSource

Parameters:

sUser -

sPasswd -

Returns:

Opened Connection

Throws:

java.sql.SQLException

Since:

4.0

getParentLogger

public java.util.logging.Logger getParentLogger()

This method is added for compatibility with Java 7 and it is not implemented

Specified by:

getParentLogger in interface javax.sql.CommonDataSource

Returns:

null

Since:

7.0

getConnectionForPId

public JDCConnection getConnectionForPId(java.lang.String sPId)
                                  throws java.sql.SQLException

Get conenction for a server process identifier

Parameters:

sPId - String Operating system process identifier at server side

Returns:

JDCConnection or null if no connection for such pid was found

Throws:

java.sql.SQLException

Since:

2.2

returnConnection

public void returnConnection(JDCConnection conn)

Return a connection to the pool

Parameters:

conn - JDCConnection returned to the pool

returnConnection

public void returnConnection(JDCConnection conn,
                    java.lang.String sCaller)

Return a connection to the pool

Parameters:

conn - JDCConnection returned to the pool

sCaller - Must be the same String passed as parameter at getConnection()

size

public int size()

Returns:

Actual connection pool size

getActivityInfo

public JDCActivityInfo getActivityInfo()
                                throws java.sql.SQLException

Get information of current activity at database to which this pool is connected

Returns:

JDCActivityInfo

Throws:

java.sql.SQLException

Since:

3.0

dumpStatistics

public java.lang.String dumpStatistics()
                                throws java.util.ConcurrentModificationException

Human readable usage statistics

Returns:

Connection pool usage statistics string

Throws:

java.util.ConcurrentModificationException - If pool is modified while iterating throught connection collection

isReadOnly

public boolean isReadOnly()

Specified by:

isReadOnly in interface com.knowgate.storage.DataSource

openTable

public com.knowgate.storage.Table openTable(com.knowgate.storage.Record oRec)
                                     throws com.knowgate.storage.StorageException

Specified by:

openTable in interface com.knowgate.storage.DataSource

Throws:

com.knowgate.storage.StorageException

openTable

public com.knowgate.storage.Table openTable(java.lang.String sName)
                                     throws com.knowgate.storage.StorageException

Specified by:

openTable in interface com.knowgate.storage.DataSource

Throws:

com.knowgate.storage.StorageException

openTable

public com.knowgate.storage.Table openTable(java.lang.String sName,
                                   java.lang.String[] sIndexes)
                                     throws com.knowgate.storage.StorageException

Specified by:

openTable in interface com.knowgate.storage.DataSource

Throws:

com.knowgate.storage.StorageException

getMetaData

public com.knowgate.storage.SchemaMetaData getMetaData()

Specified by:

getMetaData in interface com.knowgate.storage.DataSource

getDBTablesMap

public java.util.Map getDBTablesMap()
                             throws java.lang.IllegalStateException

Throws:

java.lang.IllegalStateException