oracle.jdbc.pool
Class OracleConnectionCacheImpl

java.lang.Object
  |
  +--oracle.jdbc.pool.OracleDataSource
        |
        +--oracle.jdbc.pool.OracleConnectionCacheImpl

public class OracleConnectionCacheImpl

extends OracleDataSource

implements OracleConnectionCache, java.io.Serializable, javax.naming.Referenceable

See Also:

Serialized Form

Field Summary

static int	DYNAMIC_SCHEME
static int	FIXED_RETURN_NULL_SCHEME
static int	FIXED_WAIT_SCHEME

Constructor Summary

OracleConnectionCacheImpl()
Default Constructor.

OracleConnectionCacheImpl(javax.sql.ConnectionPoolDataSource ds)
Create an OracleConnectionCacheImpl with the given ConnectionPoolDataSource from which PooledConnections have to created.

Method Summary

void	close() Physically close all the pooled connections in the cache and free all the resources.
void	closePooledConnection(javax.sql.PooledConnection pc) Invoked by the ConnectionEventListener when an error occurs on a PooledConnection/LogicalConnection signaling that it is no longer good to be used and can be closed.
int	getActiveSize() Return the total no of connections that are being used.
int	getCacheScheme() Return the Caching Scheme being used.
int	getCacheSize() Return the total no of connections in the Cache.
java.sql.Connection	getConnection() Attempt to get a logical connection from the Cache.
java.sql.Connection	getConnection(java.lang.String user, java.lang.String passwd) Attempt to get a logical connection from the Cache.
int	getMaxLimit() Return the Max limit on Connections.
int	getMinLimit() Return the minimum limit on the no of Connections.
javax.naming.Reference	getReference()
int	getStmtCacheSize() Return the size of Statement Cache.
void	reusePooledConnection(javax.sql.PooledConnection pc) Invoked by the ConnectionEventListener instance when Logical connection handles are closed signaling that the PooledConnection can be recycled into the pool for further use.
void	setCacheScheme(int s) Set the Scheme for this Cache.
void	setConnectionPoolDataSource(javax.sql.ConnectionPoolDataSource ds) Associate a ConnectionPoolDataSource datasource to the Cache.
void	setMaxLimit(int l) Set the maximum no of connections for the Cache.
void	setMinLimit(int l) Set the minimum no of connections for the Cache.
void	setStmtCacheSize(int size) Set the statement cache size.
void	setStmtCacheSize(int size, boolean clearMetaData) Set the statement cache size.

Methods inherited from class oracle.jdbc.pool.OracleDataSource

getDatabaseName, getDataSourceName, getDescription, getDriverType, getLoginTimeout, getLogWriter, getNetworkProtocol, getPortNumber, getServerName, getTNSEntryName, getURL, getUser, setDatabaseName, setDataSourceName, setDescription, setDriverType, setLoginTimeout, setLogWriter, setNetworkProtocol, setPassword, setPortNumber, setServerName, setTNSEntryName, setURL, setUser

Methods inherited from class java.lang.Object

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

Field Detail

DYNAMIC_SCHEME

public static final int DYNAMIC_SCHEME

FIXED_WAIT_SCHEME

public static final int FIXED_WAIT_SCHEME

FIXED_RETURN_NULL_SCHEME

public static final int FIXED_RETURN_NULL_SCHEME

Constructor Detail

OracleConnectionCacheImpl

public OracleConnectionCacheImpl()
                          throws java.sql.SQLException

Default Constructor. Should have an explicit call to set the URL, User, Password and other DataSource details. A ConnectionPoolDataSource is created with these options from which PooledConnections can be created.

Throws:

java.sql.SQLException - error creating Cache

OracleConnectionCacheImpl

public OracleConnectionCacheImpl(javax.sql.ConnectionPoolDataSource ds)
                          throws java.sql.SQLException

Create an OracleConnectionCacheImpl with the given ConnectionPoolDataSource from which PooledConnections have to created. In which case, url, user name, password, and other DataSource properties set on this Cache are ignored.

Parameters:

ds - a datasource from which the Cache can create PooledConnections.

Throws:

java.sql.SQLException - error creating Cache

Method Detail

setConnectionPoolDataSource

public void setConnectionPoolDataSource(javax.sql.ConnectionPoolDataSource ds)
                                 throws java.sql.SQLException

Associate a ConnectionPoolDataSource datasource to the Cache. If one already exists and Connections are already opened then an Exception is thrown. If no connections are opened, then the new ConnectionPoolDataSource overwrites the previous one.

Parameters:

ds - a datasource from which the Cache can create PooledConnections.

Throws:

java.sql.SQLException - A ConnectionPoolDataSource object already exists and connections are already open.

getConnection

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

Attempt to get a logical connection from the Cache. May return null depending upon the Schemes selected. Either a ConnectionPoolDataSource must be Set or url, username, password or Other JNDI attributes should be set on this Cache before you attempt to open Connections.

Returns:

Connection A logical Connection Object.

Throws:

java.sql.SQLException - error creating Connection Object.

Overrides:

getConnection in class OracleDataSource

getConnection

public java.sql.Connection getConnection(java.lang.String user,
                                         java.lang.String passwd)
                                  throws java.sql.SQLException

Attempt to get a logical connection from the Cache. May return null depending upon the Schemes selected. User and password arguments should match the one given either directly or from ConnectionPoolDataSource.

Returns:

Connection A logical Connection Object.

Throws:

java.sql.SQLException - error creating Connection Object.

Overrides:

getConnection in class OracleDataSource

reusePooledConnection

public void reusePooledConnection(javax.sql.PooledConnection pc)
                           throws java.sql.SQLException

Invoked by the ConnectionEventListener instance when Logical connection handles are closed signaling that the PooledConnection can be recycled into the pool for further use.

Specified by:

reusePooledConnection in interface OracleConnectionCache

Parameters:

pc - The pooled connection object that needs to be recylced.

Throws:

java.sql.SQLException - error in recycling the PooledConnection.

closePooledConnection

public void closePooledConnection(javax.sql.PooledConnection pc)
                           throws java.sql.SQLException

Invoked by the ConnectionEventListener when an error occurs on a PooledConnection/LogicalConnection signaling that it is no longer good to be used and can be closed.

Specified by:

closePooledConnection in interface OracleConnectionCache

Parameters:

pc - The pooled connection object that has to be closed because of an error.

Throws:

java.sql.SQLException - error in closing the PooledConnection

close

public void close()
           throws java.sql.SQLException

Physically close all the pooled connections in the cache and free all the resources.

Specified by:

close in interface OracleConnectionCache

Throws:

java.sql.SQLException - error in closing the PooledConnection

setMinLimit

public void setMinLimit(int l)
                 throws java.sql.SQLException

Set the minimum no of connections for the Cache.

Parameters:

l - Minimum no. of Connections.

getMinLimit

public int getMinLimit()

Return the minimum limit on the no of Connections.

Returns:

minimum limit on the no of Connections.

setMaxLimit

public void setMaxLimit(int l)
                 throws java.sql.SQLException

Set the maximum no of connections for the Cache.

Parameters:

l - maximum no. of Connections.

getMaxLimit

public int getMaxLimit()

Return the Max limit on Connections.

Returns:

int Max no of Connections that can be opened.

getCacheScheme

public int getCacheScheme()

Return the Caching Scheme being used.

Returns:

the caching scheme.

setCacheScheme

public void setCacheScheme(int s)
                    throws java.sql.SQLException

Set the Scheme for this Cache. Possible values are OracleConnectionCacheImpl.DYNAMIC_SCHEME OracleConnectionCacheImpl.FIXED_RETURN_NULL_SCHEME

Parameters:

int - Caching Scheme

getActiveSize

public int getActiveSize()

Return the total no of connections that are being used.

Returns:

total no of active connections.

getCacheSize

public int getCacheSize()

Return the total no of connections in the Cache.

Returns:

total no of connections opened.

getReference

public javax.naming.Reference getReference()
                                    throws javax.naming.NamingException

Specified by:

getReference in interface javax.naming.Referenceable

Overrides:

getReference in class OracleDataSource

setStmtCacheSize

public void setStmtCacheSize(int size)
                      throws java.sql.SQLException

Set the statement cache size. Default is 0. You cannot set this for logicalhandles obtained from PooledConnections.

If more than size cursors are already cached than they will be closed. By default the meta data of the cursor will be saved. Only data and the state will be cleared. You need to call this first to enable either type of Statement caching. When both types of Statement caching are enabled, the size is the total number of cursors cached for both the schemes together.

Parameters:

size - Size of the Cache

Throws:

java.sql.SQLException -

setStmtCacheSize

public void setStmtCacheSize(int size,
                             boolean clearMetaData)
                      throws java.sql.SQLException

Set the statement cache size. Default is 0. You cannot set this for logicalhandles obtained from PooledConnections.

If more than size cursors are already cached than they will be closed. By default, the meta data of the cursor will be saved. But if clearMetaData is set to true, even that will be cleared. You need to call this first to enable either type of Statement caching. When both types of Statement caching are enabled, the size is the total number of cursors cached for both the schemes together.

Parameters:

size - Size of the Cache

clearMetaData - Whether the state has to be cleared or not

Throws:

java.sql.SQLException -

getStmtCacheSize

public int getStmtCacheSize()

Return the size of Statement Cache.

Returns:

int Size of Statement Cache. If not set, the default 0 is returned.