SDN Controller Programming Guide

public CassandraAlert(String uid) {

super(uid, null);

}

@Override

public Id<CassandraAlert, String> getId() {

return Id.<CassandraAlert, String>valueOf(this.uid());

}

// Implement getters for immutable fields.

// Implement setters and getters for mutable fields.

// Good practice to override the following methods on transport objects:

// equals(Object), hashCode() and toString()

...

}

The function of a DTO is to list out all the columns and provide setters/getters for each of the

attributes. The application fills out all the values as necessary and passes the object down to the

persistence layer using various queries.

Distributed Database Queries

The distributed persistence layer of the HP VAN SDN Controller exposes the following queries to the

application:

 AddQuery

 CountQuery

 DeleteQuery

 DeleteQueryWithFilter

 FindQuery

 GetQuery

 PagedFindQuery

 UpdateQuery

These are generic queries and need to be qualified appropriately by the application. The

following shows a Distributed Query Service interface that provides application specific queries.

Here is the interface code from the demo application.

DistQueryService.java:

package com.hp.demo.cassandra.dao;

import com.hp.demo.cassandra.model.alert.CassandraAlert;

import com.hp.demo.cassandra.model.alert.CassandraAlertFilter;

import com.hp.demo.cassandra.model.alert.CassandraAlertSortAttribute;

import com.hp.util.MarkPage;

import com.hp.util.MarkPageRequest;

import com.hp.util.SortSpecification;