Spring Framework

org.springframework.jdbc.datasource.lookup
Class AbstractRoutingDataSource

java.lang.Object
  extended by org.springframework.jdbc.datasource.AbstractDataSource
      extended by org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource
All Implemented Interfaces:
java.sql.Wrapper, javax.sql.CommonDataSource, javax.sql.DataSource, InitializingBean
Direct Known Subclasses:
IsolationLevelDataSourceRouter

public abstract class AbstractRoutingDataSource
extends AbstractDataSource
implements 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), setDefaultTargetDataSource(java.lang.Object), determineCurrentLookupKey()

Field Summary
 
Fields inherited from class org.springframework.jdbc.datasource.AbstractDataSource
logger
 
Constructor Summary
AbstractRoutingDataSource()
           
 
Method Summary
 void afterPropertiesSet()
          Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected abstract  java.lang.Object determineCurrentLookupKey()
          Determine the current lookup key.
protected  javax.sql.DataSource determineTargetDataSource()
          Retrieve the current target DataSource.
 java.sql.Connection getConnection()
           
 java.sql.Connection getConnection(java.lang.String username, java.lang.String password)
           
protected  javax.sql.DataSource resolveSpecifiedDataSource(java.lang.Object dataSource)
          Resolve the specified data source object into a DataSource instance.
protected  java.lang.Object resolveSpecifiedLookupKey(java.lang.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(java.lang.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(java.util.Map<java.lang.Object,java.lang.Object> targetDataSources)
          Specify the map of target DataSources, with the lookup key as key.
 
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
 

Constructor Detail

AbstractRoutingDataSource

public AbstractRoutingDataSource()
Method Detail

setTargetDataSources

public void setTargetDataSources(java.util.Map<java.lang.Object,java.lang.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(java.lang.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), 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()
Description copied from interface: InitializingBean
Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:
afterPropertiesSet in interface InitializingBean

resolveSpecifiedDataSource

protected javax.sql.DataSource resolveSpecifiedDataSource(java.lang.Object dataSource)
                                                   throws java.lang.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:
java.lang.IllegalArgumentException - in case of an unsupported value type

getConnection

public java.sql.Connection getConnection()
                                  throws java.sql.SQLException
Specified by:
getConnection in interface javax.sql.DataSource
Throws:
java.sql.SQLException

getConnection

public java.sql.Connection getConnection(java.lang.String username,
                                         java.lang.String password)
                                  throws java.sql.SQLException
Specified by:
getConnection in interface javax.sql.DataSource
Throws:
java.sql.SQLException

determineTargetDataSource

protected javax.sql.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()

resolveSpecifiedLookupKey

protected java.lang.Object resolveSpecifiedLookupKey(java.lang.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

determineCurrentLookupKey

protected abstract java.lang.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.


Spring Framework