net.markenwerk.commons.interfaces

Interface Producer<Product>

Type Parameters:

Product - The type of the values to be produced.

public interface Producer<Product>

A Producer produces values of the corresponding product type.

Implementers must produce a new instance of the product, each time produce() is called.

It is therefore okay to use Producers for products that are stateful.

Producers are intended to be used in situatuation, where a mechanism to retreive a value is more desirable than having the value from the start and a Provider is not sufficient (i.e. because the product is stateful).

Producers ar espacially helpful, if it is likely that multiple instances of a stateful product will be used (i.e. multiple Iterators over the same underlying data). Another use case where a Producer may be more favourable than a {qlink Provider} is, if it is not desirable to keep the value in memory.

Since:

1.0.0

Author:

Torsten Krause (tk at markenwerk dot net)

See Also:

Provider

Method Summary

Modifier and Type	Method and Description
Product	produce() Produces a new product.

Method Detail

produce

Product produce()
         throws ProductionException

Produces a new product. This may be a costly operation

Implementers must produce a new instance of the product, each time this method is called.

It lies in the responsibility of the caller, to handle unwanted null-values by replacing them with a sensible default value or throwing a NullPointerException.

Implementers should catch any exception and wrap them in a ProductionException.

Returns:

The produced product.

Throws:

ProductionException - If the production of the product failed.