de.team33.patterns.pooling.e1

Class XProvider<S,E extends Exception>

java.lang.Object

de.team33.patterns.pooling.e1.XProvider<S,E>

Type Parameters:

S - The type of provided instances (subjects)

E - A type of exception that may be caused by the creation of new subject instances.

public class XProvider<S,E extends Exception>
extends Object

A tool that makes instances of a certain type available for the course of operations that require such an instance. The instances provided are referred to as subject in the following.

The tool maintains a number of such subjects and only creates as many as are actually required at most at the same time in its application context. The subjects are retained and reused for subsequent operations.

In this respect, this tool is suitable for providing subject types whose instantiation is relatively "expensive", which are rather unsuitable for concurrent access, but are designed for multiple or permanent use. Database or other client-server connections may be an example.

Note: this implementation cannot detect when an internal operation is taking place in the course of an operation to which the same subject could be made available.

This implementation supports checked exceptions to occur while creating new subject instances.

See Also:

Provider

Constructor Summary

Constructors

Constructor and Description
XProvider(XSupplier<S,E> newItem) Initializes a new instance giving an XSupplier that defines the intended initialization of a new subject.

Method Summary

Modifier and Type	Method and Description
<R> R	get(Function<? super S,R> function) Calls a given Function with a parameter provided for it and returns its result.
<R,X extends Exception> R	getEx(XFunction<? super S,R,X> xFunction) Calls a given XFunction with a parameter provided for it and returns its result.
void	run(Consumer<? super S> consumer) Runs a given Consumer with a parameter provided for it.
<X extends Exception> void	runEx(XConsumer<? super S,X> xConsumer) Runs a given XConsumer with a parameter provided for it.
int	size() Returns the number of currently unused subjects in stock.

Methods inherited from class java.lang.Object

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

Constructor Detail

XProvider

public XProvider(XSupplier<S,E> newItem)

Initializes a new instance giving an XSupplier that defines the intended initialization of a new subject.

Method Detail

run

public final void run(Consumer<? super S> consumer)
               throws E extends Exception

Runs a given Consumer with a parameter provided for it. The parameter is kept for future use.

While the Consumer is being executed, the parameter is exclusively available to it, but must not be "hijacked" from the context of the execution or the executing thread!

Throws:

E - if the initialization of a new subject causes one.

E extends Exception

runEx

public final <X extends Exception> void runEx(XConsumer<? super S,X> xConsumer)
                                       throws E extends Exception,
                                              X extends Exception

Runs a given XConsumer with a parameter provided for it. The parameter is kept for future use.

While the XConsumer is being executed, the parameter is exclusively available to it, but must not be "hijacked" from the context of the execution or the executing thread!

Type Parameters:

X - A type of exception that may be caused by the given XConsumer.

Throws:

E - if the initialization of a new subject causes one.

X - if the execution of the given XConsumer causes one.

E extends Exception

get

public final <R> R get(Function<? super S,R> function)
                throws E extends Exception

Calls a given Function with a parameter provided for it and returns its result. The parameter is kept for future use.

While the Function is being called, the parameter is exclusively available to it, but must not be "hijacked" from the context of the call or the executing thread!

Type Parameters:

R - The result type of the given Function

Throws:

E - if the initialization of a new subject causes one.

E extends Exception

getEx

public final <R,X extends Exception> R getEx(XFunction<? super S,R,X> xFunction)
                                      throws E extends Exception,
                                             X extends Exception

Calls a given XFunction with a parameter provided for it and returns its result. The parameter is kept for future use.

While the XFunction is being called, the parameter is exclusively available to it, but must not be "hijacked" from the context of the call or the executing thread!

Type Parameters:

R - The result type of the given XFunction

X - A type of exception that may be caused by the given XFunction.

Throws:

E - if the initialization of a new subject causes one.

X - if the execution of the given XFunction causes one.

E extends Exception

size

public final int size()

Returns the number of currently unused subjects in stock.