com.h3c.util.persistence.cassandra.query

Class GetQuery<I extends Serializable,T extends TransportObject<? super T,I>,P extends Storable<I>,C>

java.lang.Object

com.h3c.util.persistence.cassandra.query.GetQuery<I,T,P,C>

Type Parameters:

I - Type of Id for the entry to read

T - Type of the TransportObject

P - Type of Storable

C - Type of Context to execute the query.

All Implemented Interfaces:

ReadQuery<T,C>

public class GetQuery<I extends Serializable,T extends TransportObject<? super T,I>,P extends Storable<I>,C>
extends Object
implements ReadQuery<T,C>

Query to read an entry from Column Family/Table in the database.

Constructor Summary

Constructors

Constructor and Description
GetQuery(Id<T,I> id, Dao<I,T,P,?,?,C> dao) Provides ability for the business logic to perform read operation.

Method Summary

Methods

Modifier and Type	Method and Description
T	execute(C context) Execute the read operation.

Methods inherited from class java.lang.Object

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

Constructor Detail

GetQuery

public GetQuery(Id<T,I> id,
        Dao<I,T,P,?,?,C> dao)

Provides ability for the business logic to perform read operation. The applications use DAO to perform all database operations and the GetQuery provides methods that DAO can use to take the user query to the lower tiers and read the specified entry from the table/Column Family.

Parameters:

id - Id of entry to read.

dao - Dao for execute the query.

Method Detail

execute

public T execute(C context)

Execute the read operation.

Specified by:

execute in interface ReadQuery<T extends TransportObject<? super T,I>,C>

Parameters:

context - Context to execute the query

Returns:

result of GetQuery operation.

Throws:

NullPointerException - In case of context is null.

Exception - Throws Exception in case of any error in query execute.