net.sf.hajdbc.balancer.load

Class LoadBalancer<Z,D extends Database<Z>>

java.lang.Object

net.sf.hajdbc.balancer.AbstractBalancer<Z,D>

net.sf.hajdbc.balancer.load.LoadBalancer<Z,D>

Type Parameters:

D - either java.sql.Driver or javax.sql.DataSource

All Implemented Interfaces:

Iterable<D>, Collection<D>, Set<D>, Balancer<Z,D>

public class LoadBalancer<Z,D extends Database<Z>>
extends AbstractBalancer<Z,D>

Balancer implementation whose next() implementation returns the database with the least load.

Author:

Paul Ferraro

Constructor Summary

Constructors

Constructor and Description
LoadBalancer(Set<D> databases) Constructs a new LoadBalancer

Method Summary

Methods

Modifier and Type	Method and Description
boolean	add(D database)
boolean	addAll(Collection<? extends D> databases)
void	clear()
protected Set<D>	getDatabases()
<T,R,E extends Exception> R	invoke(Invoker<Z,D,T,R,E> invoker, D database, T object) Invoke the specified invoker on the specified object against the specified database, potentially informing the balancer.
D	next() Returns the next database from this balancer
D	primary() Returns the primary database.
boolean	remove(Object database)
boolean	removeAll(Collection<?> databases)
boolean	retainAll(Collection<?> databases)

Methods inherited from class net.sf.hajdbc.balancer.AbstractBalancer

backups, contains, containsAll, equals, hashCode, isEmpty, iterator, size, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

LoadBalancer

public LoadBalancer(Set<D> databases)

Constructs a new LoadBalancer

Parameters:

databases -

Method Detail

primary

public D primary()

Returns the primary database. The database returned by this method should be consistent across nodes.

Returns:

the primary database

See Also:

Balancer.primary()

getDatabases

protected Set<D> getDatabases()

Specified by:

getDatabases in class AbstractBalancer<Z,D extends Database<Z>>

See Also:

AbstractBalancer.getDatabases()

addAll

public boolean addAll(Collection<? extends D> databases)

See Also:

Set.addAll(java.util.Collection)

removeAll

public boolean removeAll(Collection<?> databases)

See Also:

Set.removeAll(java.util.Collection)

retainAll

public boolean retainAll(Collection<?> databases)

See Also:

Set.retainAll(java.util.Collection)

clear

public void clear()

See Also:

Set.clear()

remove

public boolean remove(Object database)

See Also:

Set.remove(java.lang.Object)

next

public D next()

Returns the next database from this balancer

Returns:

the next database from this balancer

See Also:

Balancer.next()

add

public boolean add(D database)

See Also:

Set.add(java.lang.Object)

invoke

public <T,R,E extends Exception> R invoke(Invoker<Z,D,T,R,E> invoker,
                                 D database,
                                 T object)
         throws E extends Exception

Invoke the specified invoker on the specified object against the specified database, potentially informing the balancer.

Type Parameters:

T - invoker target object type

R - invoker return type

E - invoker exception type

Returns:

the result of the invocation

Throws:

E

E extends Exception

See Also:

Balancer.invoke(net.sf.hajdbc.invocation.Invoker, net.sf.hajdbc.Database, java.lang.Object)