org.apache.commons.dbcp.datasources

Class InstanceKeyDataSource

public abstract class InstanceKeyDataSource extends Object implements DataSource, Referenceable, Serializable

The base class for SharedPoolDataSource and PerUserPoolDataSource. Many of the configuration properties are shared and defined here. This class is declared public in order to allow particular usage with commons-beanutils; do not make direct use of it outside of commons-dbcp.

A J2EE container will normally provide some method of initializing the DataSource whose attributes are presented as bean getters/setters and then deploying it via JNDI. It is then available to an application as a source of pooled logical connections to the database. The pool needs a source of physical connections. This source is in the form of a ConnectionPoolDataSource that can be specified via the setDataSourceName used to lookup the source via JNDI.

Although normally used within a JNDI environment, A DataSource can be instantiated and initialized as any bean. In this case the ConnectionPoolDataSource will likely be instantiated in a similar manner. This class allows the physical source of connections to be attached directly to this pool using the setConnectionPoolDataSource method.

The dbcp package contains an adapter, DriverAdapterCPDS, that can be used to allow the use of DataSource's based on this class with jdbc driver implementations that do not supply a ConnectionPoolDataSource, but still provide a java.sql.Driver implementation.

The package documentation contains an example using catalina and JNDI and it also contains a non-JNDI example.

Version: $Revision: 500687 $ $Date: 2007-01-27 16:33:47 -0700 (Sat, 27 Jan 2007) $

Author: John D. McNally

Constructor Summary
InstanceKeyDataSource()
Default no-arg constructor for Serialization
Method Summary
abstract voidclose()
Close pool being maintained by this datasource.
ConnectiongetConnection()
Attempt to establish a database connection.
ConnectiongetConnection(String username, String password)
Attempt to establish a database connection.
ConnectionPoolDataSourcegetConnectionPoolDataSource()
Get the value of connectionPoolDataSource.
StringgetDataSourceName()
Get the name of the ConnectionPoolDataSource which backs this pool.
intgetDefaultTransactionIsolation()
Get the value of defaultTransactionIsolation, which defines the state of connections handed out from this pool.
StringgetDescription()
Get the description.
StringgetJndiEnvironment(String key)
Get the value of jndiEnvironment which is used when instantiating a jndi InitialContext.
intgetLoginTimeout()
Get the value of loginTimeout.
PrintWritergetLogWriter()
Get the value of logWriter.
intgetMinEvictableIdleTimeMillis()
Returns the minimum amount of time an object may sit idle in the pool before it is eligable for eviction by the idle object evictor (if any).
intgetNumTestsPerEvictionRun()
Returns the number of objects to examine during each run of the idle object evictor thread (if any).
ReferencegetReference()
Retrieves the Reference of this object.
booleangetTestOnBorrow()
When true, objects will be {*link PoolableObjectFactory#validateObject validated} before being returned by the {*link #borrowObject} method.
booleangetTestOnReturn()
When true, objects will be {*link PoolableObjectFactory#validateObject validated} before being returned to the pool within the {*link #returnObject}.
booleangetTestWhileIdle()
When true, objects will be {*link PoolableObjectFactory#validateObject validated} by the idle object evictor (if any).
intgetTimeBetweenEvictionRunsMillis()
Returns the number of milliseconds to sleep between runs of the idle object evictor thread.
StringgetValidationQuery()
The SQL query that will be used to validate connections from this pool before returning them to the caller.
booleanisDefaultAutoCommit()
Get the value of defaultAutoCommit, which defines the state of connections handed out from this pool.
booleanisDefaultReadOnly()
Get the value of defaultReadOnly, which defines the state of connections handed out from this pool.
booleanisRollbackAfterValidation()
Whether a rollback will be issued after executing the SQL query that will be used to validate connections from this pool before returning them to the caller.
booleanisTestOnBorrow()
booleanisTestOnReturn()
booleanisTestWhileIdle()
voidsetConnectionPoolDataSource(ConnectionPoolDataSource v)
Set the backend ConnectionPoolDataSource.
voidsetDataSourceName(String v)
Set the name of the ConnectionPoolDataSource which backs this pool.
voidsetDefaultAutoCommit(boolean v)
Set the value of defaultAutoCommit, which defines the state of connections handed out from this pool.
voidsetDefaultReadOnly(boolean v)
Set the value of defaultReadOnly, which defines the state of connections handed out from this pool.
voidsetDefaultTransactionIsolation(int v)
Set the value of defaultTransactionIsolation, which defines the state of connections handed out from this pool.
voidsetDescription(String v)
Set the description.
voidsetJndiEnvironment(String key, String value)
Sets the value of the given JNDI environment property to be used when instantiating a JNDI InitialContext.
voidsetLoginTimeout(int v)
Set the value of loginTimeout.
voidsetLogWriter(PrintWriter v)
Set the value of logWriter.
voidsetMinEvictableIdleTimeMillis(int minEvictableIdleTimeMillis)
Sets the minimum amount of time an object may sit idle in the pool before it is eligable for eviction by the idle object evictor (if any).
voidsetNumTestsPerEvictionRun(int numTestsPerEvictionRun)
Sets the number of objects to examine during each run of the idle object evictor thread (if any).
voidsetRollbackAfterValidation(boolean rollbackAfterValidation)
Whether a rollback will be issued after executing the SQL query that will be used to validate connections from this pool before returning them to the caller.
voidsetTestOnBorrow(boolean testOnBorrow)
When true, objects will be {*link PoolableObjectFactory#validateObject validated} before being returned by the {*link #borrowObject} method.
voidsetTestOnReturn(boolean testOnReturn)
When true, objects will be {*link PoolableObjectFactory#validateObject validated} before being returned to the pool within the {*link #returnObject}.
voidsetTestWhileIdle(boolean testWhileIdle)
When true, objects will be {*link PoolableObjectFactory#validateObject validated} by the idle object evictor (if any).
voidsetTimeBetweenEvictionRunsMillis(int timeBetweenEvictionRunsMillis)
Sets the number of milliseconds to sleep between runs of the idle object evictor thread.
voidsetValidationQuery(String validationQuery)
The SQL query that will be used to validate connections from this pool before returning them to the caller.

Constructor Detail

InstanceKeyDataSource

public InstanceKeyDataSource()
Default no-arg constructor for Serialization

Method Detail

close

public abstract void close()
Close pool being maintained by this datasource.

getConnection

public Connection getConnection()
Attempt to establish a database connection.

getConnection

public Connection getConnection(String username, String password)
Attempt to establish a database connection.

getConnectionPoolDataSource

public ConnectionPoolDataSource getConnectionPoolDataSource()
Get the value of connectionPoolDataSource. This method will return null, if the backing datasource is being accessed via jndi.

Returns: value of connectionPoolDataSource.

getDataSourceName

public String getDataSourceName()
Get the name of the ConnectionPoolDataSource which backs this pool. This name is used to look up the datasource from a jndi service provider.

Returns: value of dataSourceName.

getDefaultTransactionIsolation

public int getDefaultTransactionIsolation()
Get the value of defaultTransactionIsolation, which defines the state of connections handed out from this pool. The value can be changed on the Connection using Connection.setTransactionIsolation(int). If this method returns -1, the default is JDBC driver dependent.

Returns: value of defaultTransactionIsolation.

getDescription

public String getDescription()
Get the description. This property is defined by jdbc as for use with GUI (or other) tools that might deploy the datasource. It serves no internal purpose.

Returns: value of description.

getJndiEnvironment

public String getJndiEnvironment(String key)
Get the value of jndiEnvironment which is used when instantiating a jndi InitialContext. This InitialContext is used to locate the backend ConnectionPoolDataSource.

Returns: value of jndiEnvironment.

getLoginTimeout

public int getLoginTimeout()
Get the value of loginTimeout.

Returns: value of loginTimeout.

getLogWriter

public PrintWriter getLogWriter()
Get the value of logWriter.

Returns: value of logWriter.

getMinEvictableIdleTimeMillis

public int getMinEvictableIdleTimeMillis()
Returns the minimum amount of time an object may sit idle in the pool before it is eligable for eviction by the idle object evictor (if any).

See Also: InstanceKeyDataSource InstanceKeyDataSource

getNumTestsPerEvictionRun

public int getNumTestsPerEvictionRun()
Returns the number of objects to examine during each run of the idle object evictor thread (if any).

See Also: InstanceKeyDataSource InstanceKeyDataSource

getReference

public Reference getReference()
Retrieves the Reference of this object. Note: InstanceKeyDataSource subclasses should override this method. The implementaion included below is not robust and will be removed at the next major version DBCP release.

Returns: The non-null Reference of this object.

Throws: NamingException If a naming exception was encountered while retrieving the reference.

getTestOnBorrow

public boolean getTestOnBorrow()
When true, objects will be {*link PoolableObjectFactory#validateObject validated} before being returned by the {*link #borrowObject} method. If the object fails to validate, it will be dropped from the pool, and we will attempt to borrow another.

See Also: InstanceKeyDataSource

getTestOnReturn

public boolean getTestOnReturn()
When true, objects will be {*link PoolableObjectFactory#validateObject validated} before being returned to the pool within the {*link #returnObject}.

See Also: InstanceKeyDataSource

getTestWhileIdle

public boolean getTestWhileIdle()
When true, objects will be {*link PoolableObjectFactory#validateObject validated} by the idle object evictor (if any). If an object fails to validate, it will be dropped from the pool.

See Also: InstanceKeyDataSource InstanceKeyDataSource

getTimeBetweenEvictionRunsMillis

public int getTimeBetweenEvictionRunsMillis()
Returns the number of milliseconds to sleep between runs of the idle object evictor thread. When non-positive, no idle object evictor thread will be run.

See Also: InstanceKeyDataSource

getValidationQuery

public String getValidationQuery()
The SQL query that will be used to validate connections from this pool before returning them to the caller. If specified, this query MUST be an SQL SELECT statement that returns at least one row.

isDefaultAutoCommit

public boolean isDefaultAutoCommit()
Get the value of defaultAutoCommit, which defines the state of connections handed out from this pool. The value can be changed on the Connection using Connection.setAutoCommit(boolean). The default is true.

Returns: value of defaultAutoCommit.

isDefaultReadOnly

public boolean isDefaultReadOnly()
Get the value of defaultReadOnly, which defines the state of connections handed out from this pool. The value can be changed on the Connection using Connection.setReadOnly(boolean). The default is false.

Returns: value of defaultReadOnly.

isRollbackAfterValidation

public boolean isRollbackAfterValidation()
Whether a rollback will be issued after executing the SQL query that will be used to validate connections from this pool before returning them to the caller.

Returns: true if a rollback will be issued after executing the validation query

Since: 1.2.2

isTestOnBorrow

public final boolean isTestOnBorrow()

See Also: InstanceKeyDataSource

isTestOnReturn

public final boolean isTestOnReturn()

See Also: InstanceKeyDataSource

isTestWhileIdle

public final boolean isTestWhileIdle()

See Also: InstanceKeyDataSource

setConnectionPoolDataSource

public void setConnectionPoolDataSource(ConnectionPoolDataSource v)
Set the backend ConnectionPoolDataSource. This property should not be set if using jndi to access the datasource.

Parameters: v Value to assign to connectionPoolDataSource.

setDataSourceName

public void setDataSourceName(String v)
Set the name of the ConnectionPoolDataSource which backs this pool. This name is used to look up the datasource from a jndi service provider.

Parameters: v Value to assign to dataSourceName.

setDefaultAutoCommit

public void setDefaultAutoCommit(boolean v)
Set the value of defaultAutoCommit, which defines the state of connections handed out from this pool. The value can be changed on the Connection using Connection.setAutoCommit(boolean). The default is true.

Parameters: v Value to assign to defaultAutoCommit.

setDefaultReadOnly

public void setDefaultReadOnly(boolean v)
Set the value of defaultReadOnly, which defines the state of connections handed out from this pool. The value can be changed on the Connection using Connection.setReadOnly(boolean). The default is false.

Parameters: v Value to assign to defaultReadOnly.

setDefaultTransactionIsolation

public void setDefaultTransactionIsolation(int v)
Set the value of defaultTransactionIsolation, which defines the state of connections handed out from this pool. The value can be changed on the Connection using Connection.setTransactionIsolation(int). The default is JDBC driver dependent.

Parameters: v Value to assign to defaultTransactionIsolation

setDescription

public void setDescription(String v)
Set the description. This property is defined by jdbc as for use with GUI (or other) tools that might deploy the datasource. It serves no internal purpose.

Parameters: v Value to assign to description.

setJndiEnvironment

public void setJndiEnvironment(String key, String value)
Sets the value of the given JNDI environment property to be used when instantiating a JNDI InitialContext. This InitialContext is used to locate the backend ConnectionPoolDataSource.

Parameters: key the JNDI environment property to set. value the value assigned to specified JNDI environment property.

setLoginTimeout

public void setLoginTimeout(int v)
Set the value of loginTimeout.

Parameters: v Value to assign to loginTimeout.

setLogWriter

public void setLogWriter(PrintWriter v)
Set the value of logWriter.

Parameters: v Value to assign to logWriter.

setMinEvictableIdleTimeMillis

public void setMinEvictableIdleTimeMillis(int minEvictableIdleTimeMillis)
Sets the minimum amount of time an object may sit idle in the pool before it is eligable for eviction by the idle object evictor (if any). When non-positive, no objects will be evicted from the pool due to idle time alone.

See Also: InstanceKeyDataSource InstanceKeyDataSource

setNumTestsPerEvictionRun

public void setNumTestsPerEvictionRun(int numTestsPerEvictionRun)
Sets the number of objects to examine during each run of the idle object evictor thread (if any).

When a negative value is supplied, ceil({*link #numIdle})/abs({*link #getNumTestsPerEvictionRun}) tests will be run. I.e., when the value is -n, roughly one nth of the idle objects will be tested per run.

See Also: InstanceKeyDataSource InstanceKeyDataSource

setRollbackAfterValidation

public void setRollbackAfterValidation(boolean rollbackAfterValidation)
Whether a rollback will be issued after executing the SQL query that will be used to validate connections from this pool before returning them to the caller. Default behavior is NOT to issue a rollback. The setting will only have an effect if a validation query is set

Parameters: rollbackAfterValidation new property value

Since: 1.2.2

setTestOnBorrow

public void setTestOnBorrow(boolean testOnBorrow)
When true, objects will be {*link PoolableObjectFactory#validateObject validated} before being returned by the {*link #borrowObject} method. If the object fails to validate, it will be dropped from the pool, and we will attempt to borrow another. For a true value to have any effect, the validationQuery property must be set to a non-null string.

See Also: InstanceKeyDataSource

setTestOnReturn

public void setTestOnReturn(boolean testOnReturn)
When true, objects will be {*link PoolableObjectFactory#validateObject validated} before being returned to the pool within the {*link #returnObject}. For a true value to have any effect, the validationQuery property must be set to a non-null string.

See Also: InstanceKeyDataSource

setTestWhileIdle

public void setTestWhileIdle(boolean testWhileIdle)
When true, objects will be {*link PoolableObjectFactory#validateObject validated} by the idle object evictor (if any). If an object fails to validate, it will be dropped from the pool. For a true value to have any effect, the validationQuery property must be set to a non-null string.

See Also: InstanceKeyDataSource InstanceKeyDataSource

setTimeBetweenEvictionRunsMillis

public void setTimeBetweenEvictionRunsMillis(int timeBetweenEvictionRunsMillis)
Sets the number of milliseconds to sleep between runs of the idle object evictor thread. When non-positive, no idle object evictor thread will be run.

See Also: InstanceKeyDataSource

setValidationQuery

public void setValidationQuery(String validationQuery)
The SQL query that will be used to validate connections from this pool before returning them to the caller. If specified, this query MUST be an SQL SELECT statement that returns at least one row. Default behavior is to test the connection when it is borrowed.
Copyright © 2001-2004 Apache Software Foundation. Documenation generated December 10 2007.