org.springframework.jdbc.datasource

Class SingleConnectionDataSource

java.lang.Object

org.springframework.jdbc.datasource.AbstractDataSource

org.springframework.jdbc.datasource.AbstractDriverBasedDataSource

org.springframework.jdbc.datasource.DriverManagerDataSource

org.springframework.jdbc.datasource.SingleConnectionDataSource

All Implemented Interfaces:

java.sql.Wrapper, javax.sql.CommonDataSource, javax.sql.DataSource, DisposableBean, SmartDataSource

public class SingleConnectionDataSource
extends DriverManagerDataSource
implements SmartDataSource, DisposableBean

Implementation of SmartDataSource that wraps a single JDBC Connection which is not closed after use. Obviously, this is not multi-threading capable.

Note that at shutdown, someone should close the underlying Connection via the close() method. Client code will never call close on the Connection handle if it is SmartDataSource-aware (e.g. uses DataSourceUtils.releaseConnection).

If client code will call close() in the assumption of a pooled Connection, like when using persistence tools, set "suppressClose" to "true". This will return a close-suppressing proxy instead of the physical Connection. Be aware that you will not be able to cast this to a native OracleConnection or the like anymore; you need to use a NativeJdbcExtractor then.

This is primarily intended for testing. For example, it enables easy testing outside an application server, for code that expects to work on a DataSource. In contrast to DriverManagerDataSource, it reuses the same Connection all the time, avoiding excessive creation of physical Connections.

Author:

Rod Johnson, Juergen Hoeller

See Also:

getConnection(), Connection.close(), DataSourceUtils.releaseConnection(java.sql.Connection, javax.sql.DataSource), NativeJdbcExtractor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	SingleConnectionDataSource.CloseSuppressingInvocationHandler Invocation handler that suppresses close calls on JDBC Connections.

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.Boolean	autoCommit Override auto-commit state?
private java.sql.Connection	connection Proxy Connection
private java.lang.Object	connectionMonitor Synchronization monitor for the shared Connection
private boolean	suppressClose Create a close-suppressing proxy?
private java.sql.Connection	target Wrapped Connection

Fields inherited from class org.springframework.jdbc.datasource.AbstractDataSource

logger

Constructor Summary

Constructors

Constructor and Description
SingleConnectionDataSource() Constructor for bean-style configuration.
SingleConnectionDataSource(java.sql.Connection target, boolean suppressClose) Create a new SingleConnectionDataSource with a given Connection.
SingleConnectionDataSource(java.lang.String url, boolean suppressClose) Create a new SingleConnectionDataSource with the given standard DriverManager parameters.
SingleConnectionDataSource(java.lang.String url, java.lang.String username, java.lang.String password, boolean suppressClose) Create a new SingleConnectionDataSource with the given standard DriverManager parameters.

Method Summary

Modifier and Type	Method and Description
private void	closeConnection() Close the underlying shared Connection.
void	destroy() Close the underlying Connection.
protected java.lang.Boolean	getAutoCommitValue() Return whether the returned Connection's "autoCommit" setting should be overridden.
protected java.sql.Connection	getCloseSuppressingConnectionProxy(java.sql.Connection target) Wrap the given Connection with a proxy that delegates every method call to it but suppresses close calls.
java.sql.Connection	getConnection() This implementation delegates to getConnectionFromDriver, using the default username and password of this DataSource.
java.sql.Connection	getConnection(java.lang.String username, java.lang.String password) Specifying a custom username and password doesn't make sense with a single Connection.
void	initConnection() Initialize the underlying Connection via the DriverManager.
protected boolean	isSuppressClose() Return whether the returned Connection will be a close-suppressing proxy or the physical Connection.
protected void	prepareConnection(java.sql.Connection con) Prepare the given Connection before it is exposed.
void	resetConnection() Reset the underlying shared Connection, to be reinitialized on next access.
void	setAutoCommit(boolean autoCommit) Set whether the returned Connection's "autoCommit" setting should be overridden.
void	setSuppressClose(boolean suppressClose) Set whether the returned Connection should be a close-suppressing proxy or the physical Connection.
boolean	shouldClose(java.sql.Connection con) This is a single Connection: Do not close it when returning to the "pool".

Methods inherited from class org.springframework.jdbc.datasource.DriverManagerDataSource

getConnectionFromDriver, getConnectionFromDriverManager, setDriverClassName

Methods inherited from class org.springframework.jdbc.datasource.AbstractDriverBasedDataSource

getConnectionFromDriver, getConnectionProperties, getPassword, getUrl, getUsername, setConnectionProperties, setPassword, setUrl, setUsername

Methods inherited from class org.springframework.jdbc.datasource.AbstractDataSource

getLoginTimeout, getLogWriter, getParentLogger, isWrapperFor, setLoginTimeout, setLogWriter, unwrap

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.sql.CommonDataSource

getLoginTimeout, getLogWriter, getParentLogger, setLoginTimeout, setLogWriter

Methods inherited from interface java.sql.Wrapper

isWrapperFor, unwrap

Field Detail

suppressClose

private boolean suppressClose

Create a close-suppressing proxy?

autoCommit

private java.lang.Boolean autoCommit

Override auto-commit state?

target

private java.sql.Connection target

Wrapped Connection

connection

private java.sql.Connection connection

Proxy Connection

connectionMonitor

private final java.lang.Object connectionMonitor

Synchronization monitor for the shared Connection

Constructor Detail

SingleConnectionDataSource

public SingleConnectionDataSource()

Constructor for bean-style configuration.

SingleConnectionDataSource

public SingleConnectionDataSource(java.lang.String url,
                                  java.lang.String username,
                                  java.lang.String password,
                                  boolean suppressClose)

Create a new SingleConnectionDataSource with the given standard DriverManager parameters.

Parameters:

url - the JDBC URL to use for accessing the DriverManager

username - the JDBC username to use for accessing the DriverManager

password - the JDBC password to use for accessing the DriverManager

suppressClose - if the returned Connection should be a close-suppressing proxy or the physical Connection

See Also:

DriverManager.getConnection(String, String, String)

SingleConnectionDataSource

public SingleConnectionDataSource(java.lang.String url,
                                  boolean suppressClose)

Create a new SingleConnectionDataSource with the given standard DriverManager parameters.

Parameters:

url - the JDBC URL to use for accessing the DriverManager

suppressClose - if the returned Connection should be a close-suppressing proxy or the physical Connection

See Also:

DriverManager.getConnection(String, String, String)

SingleConnectionDataSource

public SingleConnectionDataSource(java.sql.Connection target,
                                  boolean suppressClose)

Create a new SingleConnectionDataSource with a given Connection.

Parameters:

target - underlying target Connection

suppressClose - if the Connection should be wrapped with a Connection that suppresses close() calls (to allow for normal close() usage in applications that expect a pooled Connection but do not know our SmartDataSource interface)

Method Detail

setSuppressClose

public void setSuppressClose(boolean suppressClose)

Set whether the returned Connection should be a close-suppressing proxy or the physical Connection.

isSuppressClose

protected boolean isSuppressClose()

Return whether the returned Connection will be a close-suppressing proxy or the physical Connection.

setAutoCommit

public void setAutoCommit(boolean autoCommit)

Set whether the returned Connection's "autoCommit" setting should be overridden.

getAutoCommitValue

protected java.lang.Boolean getAutoCommitValue()

Return whether the returned Connection's "autoCommit" setting should be overridden.

Returns:

the "autoCommit" value, or null if none to be applied

getConnection

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

Description copied from class: AbstractDriverBasedDataSource

This implementation delegates to getConnectionFromDriver, using the default username and password of this DataSource.

Specified by:

getConnection in interface javax.sql.DataSource

Overrides:

getConnection in class AbstractDriverBasedDataSource

Throws:

java.sql.SQLException

See Also:

AbstractDriverBasedDataSource.getConnectionFromDriver(String, String), AbstractDriverBasedDataSource.setUsername(java.lang.String), AbstractDriverBasedDataSource.setPassword(java.lang.String)

getConnection

public java.sql.Connection getConnection(java.lang.String username,
                                         java.lang.String password)
                                  throws java.sql.SQLException

Specifying a custom username and password doesn't make sense with a single Connection. Returns the single Connection if given the same username and password; throws a SQLException else.

Specified by:

getConnection in interface javax.sql.DataSource

Overrides:

getConnection in class AbstractDriverBasedDataSource

Throws:

java.sql.SQLException

See Also:

AbstractDriverBasedDataSource.getConnectionFromDriver(String, String)

shouldClose

public boolean shouldClose(java.sql.Connection con)

This is a single Connection: Do not close it when returning to the "pool".

Specified by:

shouldClose in interface SmartDataSource

Parameters:

con - the Connection to check

Returns:

whether the given Connection should be closed

See Also:

Connection.close()

destroy

public void destroy()

Close the underlying Connection. The provider of this DataSource needs to care for proper shutdown.

As this bean implements DisposableBean, a bean factory will automatically invoke this on destruction of its cached singletons.

Specified by:

destroy in interface DisposableBean

initConnection

public void initConnection()
                    throws java.sql.SQLException

Initialize the underlying Connection via the DriverManager.

Throws:

java.sql.SQLException

resetConnection

public void resetConnection()

Reset the underlying shared Connection, to be reinitialized on next access.

prepareConnection

protected void prepareConnection(java.sql.Connection con)
                          throws java.sql.SQLException

Prepare the given Connection before it is exposed.

The default implementation applies the auto-commit flag, if necessary. Can be overridden in subclasses.

Parameters:

con - the Connection to prepare

Throws:

java.sql.SQLException

See Also:

setAutoCommit(boolean)

closeConnection

private void closeConnection()

Close the underlying shared Connection.

getCloseSuppressingConnectionProxy

protected java.sql.Connection getCloseSuppressingConnectionProxy(java.sql.Connection target)

Wrap the given Connection with a proxy that delegates every method call to it but suppresses close calls.

Parameters:

target - the original Connection to wrap

Returns:

the wrapped Connection