Managing cluster subnet groups using the Amazon SDK for Java

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 * Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * This file is licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License. A copy of
 * the License is located at
 *
 * http://aws.amazon.com/apache2.0/
 *
 * This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
*/

// snippet-sourcedescription:[CreateAndModifyClusterSubnetGroup demonstrates how to create and modify an Amazon Redshift subnet group.]
// snippet-service:[redshift]
// snippet-keyword:[Java]
// snippet-keyword:[Amazon Redshift]
// snippet-keyword:[Code Sample]
// snippet-keyword:[CreateClusterSubnetGroup]
// snippet-keyword:[DescribeClusterSubnetGroups]
// snippet-sourcetype:[full-example]
// snippet-sourcedate:[2019-02-01]
// snippet-sourceauthor:[AWS]
// snippet-start:[redshift.java.CreateAndModifyClusterSubnetGroup.complete]
package com.amazonaws.services.redshift;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.amazonaws.services.redshift.model.*;

public class CreateAndModifyClusterSubnetGroup {

    public static AmazonRedshift client;
    public static String clusterSubnetGroupName = "subnet-group-name";
    // You can use the VPC console to find subnet IDs to use.
    public static String subnetId1 = "***provide a subnet ID****";
    public static String subnetId2 = "***provide a subnet ID****";

    public static void main(String[] args) throws IOException {

        // Default client using the {@link com.amazonaws.auth.DefaultAWSCredentialsProviderChain}
       client = AmazonRedshiftClientBuilder.defaultClient();

        try {
             createClusterSubnetGroup();
             describeClusterSubnetGroups();
             modifyClusterSubnetGroup();
        } catch (Exception e) {
            System.err.println("Operation failed: " + e.getMessage());
        }
    }

    private static void createClusterSubnetGroup() {
        CreateClusterSubnetGroupRequest request = new CreateClusterSubnetGroupRequest()
            .withClusterSubnetGroupName(clusterSubnetGroupName)
            .withDescription("my cluster subnet group")
            .withSubnetIds(subnetId1);
        client.createClusterSubnetGroup(request);
        System.out.println("Created cluster subnet group: " + clusterSubnetGroupName);
    }

    private static void modifyClusterSubnetGroup() {
        // Get existing subnet list.
        DescribeClusterSubnetGroupsRequest request1 = new DescribeClusterSubnetGroupsRequest()
            .withClusterSubnetGroupName(clusterSubnetGroupName);
        DescribeClusterSubnetGroupsResult result1 = client.describeClusterSubnetGroups(request1);
        List<String> subnetNames = new ArrayList<String>();
        // We can work with just the first group returned since we requested info about one group.
        for (Subnet subnet : result1.getClusterSubnetGroups().get(0).getSubnets()) {
            subnetNames.add(subnet.getSubnetIdentifier());
        }
        // Add to existing subnet list.
        subnetNames.add(subnetId2);

        ModifyClusterSubnetGroupRequest request = new ModifyClusterSubnetGroupRequest()
            .withClusterSubnetGroupName(clusterSubnetGroupName)
            .withSubnetIds(subnetNames);
        ClusterSubnetGroup result2 = client.modifyClusterSubnetGroup(request);
        System.out.println("\nSubnet group modified.");
        printResultSubnetGroup(result2);
    }


    private static void describeClusterSubnetGroups() {
        DescribeClusterSubnetGroupsRequest request = new DescribeClusterSubnetGroupsRequest()
        .withClusterSubnetGroupName(clusterSubnetGroupName);

    DescribeClusterSubnetGroupsResult result = client.describeClusterSubnetGroups(request);
    printResultSubnetGroups(result);
    }

    private static void printResultSubnetGroups(DescribeClusterSubnetGroupsResult result)
    {
        if (result == null)
        {
            System.out.println("\nDescribe cluster subnet groups result is null.");
            return;
        }

        for (ClusterSubnetGroup group : result.getClusterSubnetGroups())
        {
            printResultSubnetGroup(group);
        }

    }
    private static void printResultSubnetGroup(ClusterSubnetGroup group) {
        System.out.format("Name: %s, Description: %s\n", group.getClusterSubnetGroupName(), group.getDescription());
        for (Subnet subnet : group.getSubnets()) {
            System.out.format("  Subnet: %s, %s, %s\n", subnet.getSubnetIdentifier(),
                    subnet.getSubnetAvailabilityZone().getName(), subnet.getSubnetStatus());
        }
    }
}
// snippet-end:[redshift.java.CreateAndModifyClusterSubnetGroup.complete]