public static void main(String[] args)
{
    final String USAGE =
        "To run this example, supply an instance id\n" +
        "Ex: RebootInstance <instance_id>\n";

    if (args.length != 1) {
        System.out.println(USAGE);
        System.exit(1);
    }

    String instance_id = args[0];

    final AmazonEC2 ec2 = AmazonEC2ClientBuilder.defaultClient();

    RebootInstancesRequest request = new RebootInstancesRequest()
        .withInstanceIds(instance_id);

    RebootInstancesResult response = ec2.rebootInstances(request);

    System.out.printf(
        "Successfully rebooted instance %s", instance_id);
}
 

private void doReboot(List<CloudInstance> affectedVMs, AmazonEC2Client amazonEC2Client, List<CloudInstance> instances) {
    for (CloudInstance instance: instances) {
        try {
            amazonEC2Client.rebootInstances(new RebootInstancesRequest().withInstanceIds(List.of(instance.getInstanceId())));
            affectedVMs.add(instance);
        } catch (AmazonEC2Exception e) {
            LOGGER.warn(String.format("Unable to reboot instance %s", instance), e);
        }
    }
}
 

@Override
public void reboot(RebootInstancesRequest request) {
    reboot(request, null);
}
 

@Override
public void reboot(RebootInstancesRequest request, ResultCapture<Void>
        extractor) {

    resource.performAction("Reboot", request, extractor);
}
 

@Override
public void reboot(ResultCapture<Void> extractor) {
    RebootInstancesRequest request = new RebootInstancesRequest();
    reboot(request, extractor);
}
 

public static void main(String[] args) {
   
    // Set up the client
    AmazonEC2 ec2Client = AmazonEC2ClientBuilder.standard()
        .withCredentials(new AWSStaticCredentialsProvider(credentials))
        .withRegion(Regions.US_EAST_1)
        .build();

    // Create a security group
    CreateSecurityGroupRequest createSecurityGroupRequest = new CreateSecurityGroupRequest().withGroupName("BaeldungSecurityGroup")
        .withDescription("Baeldung Security Group");
    ec2Client.createSecurityGroup(createSecurityGroupRequest);

    // Allow HTTP and SSH traffic
    IpRange ipRange1 = new IpRange().withCidrIp("0.0.0.0/0");

    IpPermission ipPermission1 = new IpPermission().withIpv4Ranges(Arrays.asList(new IpRange[] { ipRange1 }))
        .withIpProtocol("tcp")
        .withFromPort(80)
        .withToPort(80);

    IpPermission ipPermission2 = new IpPermission().withIpv4Ranges(Arrays.asList(new IpRange[] { ipRange1 }))
        .withIpProtocol("tcp")
        .withFromPort(22)
        .withToPort(22);

    AuthorizeSecurityGroupIngressRequest authorizeSecurityGroupIngressRequest = new AuthorizeSecurityGroupIngressRequest()
        .withGroupName("BaeldungSecurityGroup")
        .withIpPermissions(ipPermission1, ipPermission2);

    ec2Client.authorizeSecurityGroupIngress(authorizeSecurityGroupIngressRequest);

    // Create KeyPair
    CreateKeyPairRequest createKeyPairRequest = new CreateKeyPairRequest()
        .withKeyName("baeldung-key-pair");
    CreateKeyPairResult createKeyPairResult = ec2Client.createKeyPair(createKeyPairRequest);
    String privateKey = createKeyPairResult
        .getKeyPair()
        .getKeyMaterial(); // make sure you keep it, the private key, Amazon doesn't store the private key

    // See what key-pairs you've got
    DescribeKeyPairsRequest describeKeyPairsRequest = new DescribeKeyPairsRequest();
    DescribeKeyPairsResult describeKeyPairsResult = ec2Client.describeKeyPairs(describeKeyPairsRequest);

    // Launch an Amazon Instance
    RunInstancesRequest runInstancesRequest = new RunInstancesRequest().withImageId("ami-97785bed") // https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AMIs.html | https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/usingsharedamis-finding.html
        .withInstanceType("t2.micro") // https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html
        .withMinCount(1)
        .withMaxCount(1)
        .withKeyName("baeldung-key-pair") // optional - if not present, can't connect to instance
        .withSecurityGroups("BaeldungSecurityGroup");

    String yourInstanceId = ec2Client.runInstances(runInstancesRequest).getReservation().getInstances().get(0).getInstanceId();

    // Start an Instance
    StartInstancesRequest startInstancesRequest = new StartInstancesRequest()
        .withInstanceIds(yourInstanceId);

    ec2Client.startInstances(startInstancesRequest);

    // Monitor Instances
    MonitorInstancesRequest monitorInstancesRequest = new MonitorInstancesRequest()
        .withInstanceIds(yourInstanceId);

    ec2Client.monitorInstances(monitorInstancesRequest);

    UnmonitorInstancesRequest unmonitorInstancesRequest = new UnmonitorInstancesRequest()
        .withInstanceIds(yourInstanceId);

    ec2Client.unmonitorInstances(unmonitorInstancesRequest);

    // Reboot an Instance

    RebootInstancesRequest rebootInstancesRequest = new RebootInstancesRequest()
        .withInstanceIds(yourInstanceId);

    ec2Client.rebootInstances(rebootInstancesRequest);

    // Stop an Instance
    StopInstancesRequest stopInstancesRequest = new StopInstancesRequest()
        .withInstanceIds(yourInstanceId);

    ec2Client.stopInstances(stopInstancesRequest)
        .getStoppingInstances()
        .get(0)
        .getPreviousState()
        .getName();

    // Describe an Instance
    DescribeInstancesRequest describeInstancesRequest = new DescribeInstancesRequest();
    DescribeInstancesResult response = ec2Client.describeInstances(describeInstancesRequest);
    System.out.println(response.getReservations()
        .get(0)
        .getInstances()
        .get(0)
        .getKernelId());
}
 

/**
 * Performs the <code>Reboot</code> action.
 *
 * <p>
 * The following request parameters will be populated from the data of this
 * <code>Instance</code> resource, and any conflicting parameter value set
 * in the request will be overridden:
 * <ul>
 *   <li>
 *     <b><code>InstanceIds.0</code></b>
 *         - mapped from the <code>Id</code> identifier.
 *   </li>
 * </ul>
 *
 * <p>
 *
 * @see RebootInstancesRequest
 */
void reboot(RebootInstancesRequest request);
 

/**
 * Performs the <code>Reboot</code> action and use a ResultCapture to
 * retrieve the low-level client response.
 *
 * <p>
 * The following request parameters will be populated from the data of this
 * <code>Instance</code> resource, and any conflicting parameter value set
 * in the request will be overridden:
 * <ul>
 *   <li>
 *     <b><code>InstanceIds.0</code></b>
 *         - mapped from the <code>Id</code> identifier.
 *   </li>
 * </ul>
 *
 * <p>
 *
 * @see RebootInstancesRequest
 */
void reboot(RebootInstancesRequest request, ResultCapture<Void> extractor);