com.hp.util.persistence

Interface ReadQuery<T,C>

Type Parameters:

T - Type of the TransportObject object

C - Type of the context of the query. This varies with the implementation of the application and the database used.

All Known Implementing Classes:

CountQuery, FindQuery, GetQuery, PagedFindQuery, ReadQueryDecorator, ReadQueryLoggingDecorator, TransReadAllDecorator, TransReadQueryDecorator

public interface ReadQuery<T,C>

ReadQuery provides ability for the business logic to perform Read operations on the persistence layer. The applications use DAO to perform all database operations and the WriteQuery interface provides methods that DAO can use to infer the type of query, the filter conditions, the sort specifications and take the user query to the lower tiers.

WriteQuery.execute(C) is a single call that the application/business logic makes to perform a read operation. The implemented execute method takes the Context as parameter. The Context varies with implementation and DAO uses this context to pass data down to the entity manager.

Author:

Nachiket Abhyankar

Method Summary

Modifier and Type	Method and Description
T	execute(C context) This is the single execute method provided by the ReadQuery interface.

Method Detail

execute

T execute(C context)
   throws Exception

This is the single execute method provided by the ReadQuery interface. The application/business logic prepares a read query and as the last step, calls this method to transmit data to the underlying tiers. This data is read using DAO and Entity Manager.

Parameters:

context - - The DataStore context. Provides the context to the query.

Returns:

Transport object that has been read.

Throws:

Exception