//snippet-sourcedescription:[ListAccountAliases.java demonstrates how to list all aliases associated with an AWS account.]
//snippet-keyword:[SDK for Java 2.0]
//snippet-keyword:[Code Sample]
//snippet-service:[iam]
//snippet-sourcetype:[full-example]
//snippet-sourcedate:[03/02/2020]
//snippet-sourceauthor:[scmacdon-aws]
/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * 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
 *
 * or in the "license" file accompanying this file. 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.
 */
package com.example.iam;
// snippet-start:[iam.java2.list_account_aliases.complete]
// snippet-start:[iam.java2.list_account_aliases.import]
import software.amazon.awssdk.services.iam.model.IamException;
import software.amazon.awssdk.services.iam.model.ListAccountAliasesResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.iam.IamClient;

// snippet-end:[iam.java2.list_account_aliases.import]
/**
 * Lists all aliases associated with an AWS account
 */
public class ListAccountAliases {
    public static void main(String[] args) {

        // snippet-start:[iam.java2.list_account_aliases.main]
        Region region = Region.AWS_GLOBAL;
        IamClient iam = IamClient.builder().region(region).build();

        try {
            ListAccountAliasesResponse response = iam.listAccountAliases();

            for (String alias : response.accountAliases()) {
                System.out.printf("Retrieved account alias %s", alias);
            }
        // snippet-end:[iam.java2.list_account_aliases.main]
        } catch (IamException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
        System.out.println("Done");
    }
}
// snippet-end:[iam.java2.list_account_aliases.complete]

//snippet-sourcedescription:[ListAccountAliases.java demonstrates how to list all aliases associated with an AWS account.]
//snippet-keyword:[SDK for Java 2.0]
//snippet-keyword:[Code Sample]
//snippet-service:[AWS IAM]
//snippet-sourcetype:[full-example]
//snippet-sourcedate:[03/02/2020]
//snippet-sourceauthor:[scmacdon-aws]
/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * 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
 *
 * or in the "license" file accompanying this file. 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.
 */
package com.example.iam;

// snippet-start:[iam.java2.list_account_aliases.import]
import software.amazon.awssdk.services.iam.model.IamException;
import software.amazon.awssdk.services.iam.model.ListAccountAliasesResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.iam.IamClient;
// snippet-end:[iam.java2.list_account_aliases.import]

/**
 * Lists all aliases associated with an AWS account
 */
public class ListAccountAliases {
    public static void main(String[] args) {

        Region region = Region.AWS_GLOBAL;
        IamClient iam = IamClient.builder().region(region).build();
        listAliases(iam);
    }

    // snippet-start:[iam.java2.list_account_aliases.main]
    public static void listAliases(IamClient iam) {

        try {
            ListAccountAliasesResponse response = iam.listAccountAliases();

            for (String alias : response.accountAliases()) {
                System.out.printf("Retrieved account alias %s", alias);
            }

        } catch (IamException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
        System.out.println("Done");
    }
    // snippet-end:[iam.java2.list_account_aliases.main]
}

Update ListAccountAliases.java