incompatible types: com.amazonaws.waiters.WaiterParameters is not a functional interface

When I create a dynamodb table, I try to use waiters to wait AWS service to complete its action.

CreateTableRequest createRequest = new CreateTableRequest()
            .withTableName(tableName);
    
CreateTableResult createResult = dynamoDbClient.createTable(createRequest);
dynamoDbClient.waiters().tableExists().run(() -> new DescribeTableRequest(tableName));
return dynamoDB.getTable(tableName);

But I get:

incompatible types: com.amazonaws.waiters.WaiterParameters is not a functional interface

I'm new to Java, what's a functional interface? How can I get around this problem?

After dividing into 2 lines I was able to see the problem, new WaiterParameters<> is missing.

Waiter<DescribeTableRequest> waiter = dynamoDbClient.waiters().tableExists();
waiter.run(new WaiterParameters<>(new DescribeTableRequest(tableName)));

Use AWS SDK for Java V2, not the AWS SDK for Java V1 - which is no longer recommended to use as specified on this AWS page.

You can use Waiters easily using the Amazon Dynamo V2 API. See this code example.

//snippet-sourcedescription:[CreateTable.java demonstrates how to create an Amazon DynamoDB table by using a waiter.]
//snippet-keyword:[SDK for Java v2]
//snippet-service:[Amazon DynamoDB]
/*
Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
SPDX-License-Identifier: Apache-2.0
*/
package com.example.dynamodb;
// snippet-start:[dynamodb.java2.create_table.import]
import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeDefinition;
import software.amazon.awssdk.services.dynamodb.model.CreateTableRequest;
import software.amazon.awssdk.services.dynamodb.model.CreateTableResponse;
import software.amazon.awssdk.services.dynamodb.model.DescribeTableRequest;
import software.amazon.awssdk.services.dynamodb.model.DescribeTableResponse;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.KeySchemaElement;
import software.amazon.awssdk.services.dynamodb.model.KeyType;
import software.amazon.awssdk.services.dynamodb.model.ProvisionedThroughput;
import software.amazon.awssdk.services.dynamodb.model.ScalarAttributeType;
import software.amazon.awssdk.services.dynamodb.waiters.DynamoDbWaiter;
// snippet-end:[dynamodb.java2.create_table.import]
/**
* Before running this Java V2 code example, set up your development environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class CreateTable {
public static void main(String[] args) {
final String usage = "\n" +
"Usage:\n" +
"    <tableName> <key>\n\n" +
"Where:\n" +
"    tableName - The Amazon DynamoDB table to create (for example, Music3).\n\n" +
"    key - The key for the Amazon DynamoDB table (for example, Artist).\n" ;
if (args.length != 2) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String key = args[1];
System.out.println("Creating an Amazon DynamoDB table "+tableName +" with a simple primary key: " +key );
ProfileCredentialsProvider credentialsProvider = ProfileCredentialsProvider.create();
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.credentialsProvider(credentialsProvider)
.region(region)
.build();
String result = createTable(ddb, tableName, key);
System.out.println("New table is "+result);
ddb.close();
}
// snippet-start:[dynamodb.java2.create_table.main]
public static String createTable(DynamoDbClient ddb, String tableName, String key) {
DynamoDbWaiter dbWaiter = ddb.waiter();
CreateTableRequest request = CreateTableRequest.builder()
.attributeDefinitions(AttributeDefinition.builder()
.attributeName(key)
.attributeType(ScalarAttributeType.S)
.build())
.keySchema(KeySchemaElement.builder()
.attributeName(key)
.keyType(KeyType.HASH)
.build())
.provisionedThroughput(ProvisionedThroughput.builder()
.readCapacityUnits(new Long(10))
.writeCapacityUnits(new Long(10))
.build())
.tableName(tableName)
.build();
String newTable ="";
try {
CreateTableResponse response = ddb.createTable(request);
DescribeTableRequest tableRequest = DescribeTableRequest.builder()
.tableName(tableName)
.build();
// Wait until the Amazon DynamoDB table is created.
WaiterResponse<DescribeTableResponse> waiterResponse = dbWaiter.waitUntilTableExists(tableRequest);
waiterResponse.matched().response().ifPresent(System.out::println);
newTable = response.tableDescription().tableName();
return newTable;
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
return "";
}
// snippet-end:[dynamodb.java2.create_table.main]
}

To read more about waiter and the AWS SDK for Java V2, see:

Using waiters in the AWS SDK for Java 2.x