org.springframework.jdbc.datasource.lookup

Class AbstractRoutingDataSource

java.lang.Object

org.springframework.jdbc.datasource.AbstractDataSource

org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource

All Implemented Interfaces:

Wrapper, CommonDataSource, DataSource, org.springframework.beans.factory.InitializingBean

Direct Known Subclasses:

IsolationLevelDataSourceRouter

public abstract class AbstractRoutingDataSource
extends AbstractDataSource
implements org.springframework.beans.factory.InitializingBean

Abstract DataSource implementation that routes getConnection() calls to one of various target DataSources based on a lookup key. The latter is usually (but not necessarily) determined through some thread-bound transaction context.

Since:

2.0.1

Author:

Juergen Hoeller

See Also:

setTargetDataSources(java.util.Map<java.lang.Object, java.lang.Object>), setDefaultTargetDataSource(java.lang.Object), determineCurrentLookupKey()

Field Summary

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

logger

Constructor Summary

Constructors

Constructor and Description
AbstractRoutingDataSource()

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet()
protected abstract Object	determineCurrentLookupKey() Determine the current lookup key.
protected DataSource	determineTargetDataSource() Retrieve the current target DataSource.
Connection	getConnection()
Connection	getConnection(String username, String password)
boolean	isWrapperFor(Class<?> iface)
protected DataSource	resolveSpecifiedDataSource(Object dataSource) Resolve the specified data source object into a DataSource instance.
protected Object	resolveSpecifiedLookupKey(Object lookupKey) Resolve the given lookup key object, as specified in the targetDataSources map, into the actual lookup key to be used for matching with the current lookup key.
void	setDataSourceLookup(DataSourceLookup dataSourceLookup) Set the DataSourceLookup implementation to use for resolving data source name Strings in the targetDataSources map.
void	setDefaultTargetDataSource(Object defaultTargetDataSource) Specify the default target DataSource, if any.
void	setLenientFallback(boolean lenientFallback) Specify whether to apply a lenient fallback to the default DataSource if no specific DataSource could be found for the current lookup key.
void	setTargetDataSources(Map<Object,Object> targetDataSources) Specify the map of target DataSources, with the lookup key as key.
<T> T	unwrap(Class<T> iface)

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

getLoginTimeout, getLogWriter, getParentLogger, setLoginTimeout, setLogWriter

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractRoutingDataSource

public AbstractRoutingDataSource()

Method Detail

setTargetDataSources

public void setTargetDataSources(Map<Object,Object> targetDataSources)

Specify the map of target DataSources, with the lookup key as key. The mapped value can either be a corresponding DataSource instance or a data source name String (to be resolved via a DataSourceLookup).

The key can be of arbitrary type; this class implements the generic lookup process only. The concrete key representation will be handled by resolveSpecifiedLookupKey(Object) and determineCurrentLookupKey().

setDefaultTargetDataSource

public void setDefaultTargetDataSource(Object defaultTargetDataSource)

Specify the default target DataSource, if any.

The mapped value can either be a corresponding DataSource instance or a data source name String (to be resolved via a DataSourceLookup).

This DataSource will be used as target if none of the keyed targetDataSources match the determineCurrentLookupKey() current lookup key.

setLenientFallback

public void setLenientFallback(boolean lenientFallback)

Specify whether to apply a lenient fallback to the default DataSource if no specific DataSource could be found for the current lookup key.

Default is "true", accepting lookup keys without a corresponding entry in the target DataSource map - simply falling back to the default DataSource in that case.

Switch this flag to "false" if you would prefer the fallback to only apply if the lookup key was null. Lookup keys without a DataSource entry will then lead to an IllegalStateException.

See Also:

setTargetDataSources(java.util.Map<java.lang.Object, java.lang.Object>), setDefaultTargetDataSource(java.lang.Object), determineCurrentLookupKey()

setDataSourceLookup

public void setDataSourceLookup(DataSourceLookup dataSourceLookup)

Set the DataSourceLookup implementation to use for resolving data source name Strings in the targetDataSources map.

Default is a JndiDataSourceLookup, allowing the JNDI names of application server DataSources to be specified directly.

afterPropertiesSet

public void afterPropertiesSet()

Specified by:

afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

resolveSpecifiedLookupKey

protected Object resolveSpecifiedLookupKey(Object lookupKey)

Resolve the given lookup key object, as specified in the targetDataSources map, into the actual lookup key to be used for matching with the current lookup key.

The default implementation simply returns the given key as-is.

Parameters:

lookupKey - the lookup key object as specified by the user

Returns:

the lookup key as needed for matching

resolveSpecifiedDataSource

protected DataSource resolveSpecifiedDataSource(Object dataSource)
                                         throws IllegalArgumentException

Resolve the specified data source object into a DataSource instance.

The default implementation handles DataSource instances and data source names (to be resolved via a DataSourceLookup).

Parameters:

dataSource - the data source value object as specified in the targetDataSources map

Returns:

the resolved DataSource (never null)

Throws:

IllegalArgumentException - in case of an unsupported value type

getConnection

public Connection getConnection()
                         throws SQLException

Specified by:

getConnection in interface DataSource

Throws:

SQLException

getConnection

public Connection getConnection(String username,
                                String password)
                         throws SQLException

Specified by:

getConnection in interface DataSource

Throws:

SQLException

unwrap

public <T> T unwrap(Class<T> iface)
             throws SQLException

Specified by:

unwrap in interface Wrapper

Overrides:

unwrap in class AbstractDataSource

Throws:

SQLException

isWrapperFor

public boolean isWrapperFor(Class<?> iface)
                     throws SQLException

Specified by:

isWrapperFor in interface Wrapper

Overrides:

isWrapperFor in class AbstractDataSource

Throws:

SQLException

determineTargetDataSource

protected DataSource determineTargetDataSource()

Retrieve the current target DataSource. Determines the current lookup key, performs a lookup in the targetDataSources map, falls back to the specified default target DataSource if necessary.

See Also:

determineCurrentLookupKey()

determineCurrentLookupKey

protected abstract Object determineCurrentLookupKey()

Determine the current lookup key. This will typically be implemented to check a thread-bound transaction context.

Allows for arbitrary keys. The returned key needs to match the stored lookup key type, as resolved by the resolveSpecifiedLookupKey(java.lang.Object) method.