how can i create a load balancer in AWS using the AWS java sdk

Question

as part of a project i need to create a new load balancer on amazon AWS. i need to do it using the java sdk

how can i set the load balancer up using code?

here is what i tried so far without success.

//create load balancer
        CreateLoadBalancerRequest lbRequest = new CreateLoadBalancerRequest();
        lbRequest.setLoadBalancerName("loader");
        List<Listener> listeners = new ArrayList<Listener>(1);
        listeners.add(new Listener("HTTP", 80, 80));
        lbRequest.withAvailabilityZones(availabilityZone1,availabilityZone2);
        lbRequest.setListeners(listeners);

        CreateLoadBalancerResult lbResult=new CreateLoadBalancerResult();
        System.out.println("created load balancer loader");

Answer 1

V2 code --

package com.example.loadbalance;

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.elasticloadbalancing.ElasticLoadBalancingClient;
import software.amazon.awssdk.services.elasticloadbalancing.model.CreateLoadBalancerRequest;
import software.amazon.awssdk.services.elasticloadbalancing.model.ElasticLoadBalancingException;
import software.amazon.awssdk.services.elasticloadbalancing.model.CreateLoadBalancerResponse;
import software.amazon.awssdk.services.elasticloadbalancing.model.Listener;

import java.util.ArrayList;
import java.util.List;

public class CreateLoadBalancer {

    public static void main(String[] args) {

        Region region = Region.US_WEST_2;
        ElasticLoadBalancingClient loadClient = ElasticLoadBalancingClient.builder()
                .region(region)
                .build();

        try {

            Listener listener = Listener.builder()
                .protocol("HTTP")
                .instancePort(80)
                .loadBalancerPort(80)
                .build();

            List<Listener> listeners = new ArrayList<>();
            listeners.add(listener);

            List<String> avZone = new ArrayList<String>();
            avZone.add("us-west-2a");
            avZone.add("us-west-2b");

            //Define security groups
            List<String> secGroups = new ArrayList<String>();
            secGroups.add("sg-7aba5827");

        CreateLoadBalancerRequest loadBalancerRequest = CreateLoadBalancerRequest.builder()
                .availabilityZones(avZone)
                .securityGroups(secGroups)
                .loadBalancerName("LoadB44")
                 .listeners(listeners)
                .scheme("internet-facing")
                .build();

            CreateLoadBalancerResponse response = loadClient.createLoadBalancer(loadBalancerRequest);
            System.out.println("The DNS Name is "+response.dnsName());

    } catch (ElasticLoadBalancingException e) {
        System.err.println(e.awsErrorDetails().errorMessage());
        System.exit(1);
    }

    }
}

Answer 2

well finelly i got it:

first create an elb client

AmazonElasticLoadBalancingClient elb = new AmazonElasticLoadBalancingClient(credentials);

then

use it to initiate the request

  //create load balancer
        CreateLoadBalancerRequest lbRequest = new CreateLoadBalancerRequest();
        lbRequest.setLoadBalancerName("loader");
        List<Listener> listeners = new ArrayList<Listener>(1);
        listeners.add(new Listener("HTTP", 80, 80));
        lbRequest.withAvailabilityZones(availabilityZone1,availabilityZone2);
        lbRequest.setListeners(listeners);

        CreateLoadBalancerResult lbResult=elb.createLoadBalancer(lbRequest);
        System.out.println("created load balancer loader");

then register your instances to the Load balancer

//get the running instances
        DescribeInstancesResult describeInstancesRequest = ec2.describeInstances();
        List<Reservation> reservations = describeInstancesRequest.getReservations();
        List<Instance> instances = new ArrayList<Instance>();

        for (Reservation reservation : reservations) {
            instances.addAll(reservation.getInstances());
        }


        //get instance id's
        String id;
        List instanceId=new ArrayList();
        List instanceIdString=new ArrayList();
        Iterator<Instance> iterator=instances.iterator();
        while (iterator.hasNext())
        {
            id=iterator.next().getInstanceId();
            instanceId.add(new com.amazonaws.services.elasticloadbalancing.model.Instance(id));
            instanceIdString.add(id);
        }


        //register the instances to the balancer
        RegisterInstancesWithLoadBalancerRequest register =new RegisterInstancesWithLoadBalancerRequest();
        register.setLoadBalancerName("loader");
        register.setInstances((Collection)instanceId);
        RegisterInstancesWithLoadBalancerResult registerWithLoadBalancerResult= elb.registerInstancesWithLoadBalancer(register);

and you are done...