How to access data service nested query results using a client stub?

Applies to : WSAS 2.3(and bellow), DS-1.0.1(and bellow)

Background

I will be using the NestQuerySample.dbs created in 'How to use Data Service nested query feature?' for this example.

Step 1 : Generate Client Stub

Click 'Generate Client' link on NestedQuerySample details page. (See Image bellow). A jar file containing Java client stub will be created & you will be prompted to save it.

Step 2 : Client Project

Create a project in your IDE. Add the jar file created in previous step as library to your project. Add all jar files in $WSAS_HOME/lib to your project.

Step 3 : Client code

Create a class called 'Client1' inside the package 'org.abc.dataservices'.Content that should go inside Client1.java is as follows.

package org.abc.dataservices;

import java.rmi.RemoteException;
import org.apache.axis2.AxisFault;
import org.wso2.ws.dataservice.Employee;
import org.wso2.ws.dataservice.EmployeesE;
import org.wso2.ws.dataservice.GetEmployees;
import org.wso2.wsas.client.NestedQuerySampleStub;
import com.abc.salary.Salary;
public class Client1 {
  public static void main(String[] args) {
	try {
		NestedQuerySampleStub stub = 
			new NestedQuerySampleStub("http://localhost:9762/services/NestedQuerySample");
		GetEmployees getEmployees = new GetEmployees();
		EmployeesE result = stub.getEmployees(getEmployees);
		if(result != null){
			Employee[] employee = result.getEmployees().getEmployee();
			for (int a = 0; a < employee.length; a++) {
				//accessing parent 
				Employee emp = employee[a];
				System.out.println(emp.getFirstName() + " : "+emp.getEmail());
				//accessing nested salary
				if(emp.getSalaries() != null){
					Salary[] salaries = emp.getSalaries().getSalary();
					if(salaries != null){
						for (int b = 0; b < salaries.length; b++) {
							Salary salary = salaries[b];
							System.out.println("--> salary = "+salary.getAmount());
						}					
					}
				}
			}
		}else{
			System.out.println("No employee records found!!.");
		}
	} catch (AxisFault e) {
		e.printStackTrace();
	} catch (RemoteException e) {
		e.printStackTrace();
	}
  }
}

Step 4 : Testing the client

Compile & run 'Client1' using your IDE (you might want to write a build file for this later on).
A result (based on sample data populated - Check Step 1 here.) similar to following will be printed to your console.

Step 5 : Analyzing Client1 code

Structure of results returned from NestedQuerySample service is as follows.

You can observe a similar pattern in the client code that reads the response received by the stub.