AWS SDK Java V2 Dynamodb

<!-- Low-level DynamoDB client -->
<dependency>
    <groupId>software.amazon.awssdk</groupId>
    <artifactId>dynamodb</artifactId>
</dependency>

<!-- Enhanced client (recommended) -->
<dependency>
    <groupId>software.amazon.awssdk</groupId>
    <artifactId>dynamodb-enhanced</artifactId>
</dependency>

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;

DynamoDbClient dynamoDb = DynamoDbClient.builder()
    .region(Region.US_EAST_1)
    .build();

import software.amazon.awssdk.enhanced.dynamodb.DynamoDbEnhancedClient;

DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder()
    .dynamoDbClient(dynamoDb)
    .build();

@DynamoDbBean
public class Customer {

    @DynamoDbPartitionKey
    private String customerId;

    @DynamoDbAttribute("customer_name")
    private String name;

    private String email;

    @DynamoDbSortKey
    private String orderId;

    // Getters and setters
}

// Create or update item
DynamoDbTable<Customer> table = enhancedClient.table("Customers", TableSchema.fromBean(Customer.class));
table.putItem(customer);

// Get item
Customer result = table.getItem(Key.builder().partitionValue(customerId).build());

// Update item
return table.updateItem(customer);

// Delete item
table.deleteItem(Key.builder().partitionValue(customerId).build());

// Get item with composite key
Order order = table.getItem(Key.builder()
    .partitionValue(customerId)
    .sortValue(orderId)
    .build());

import software.amazon.awssdk.enhanced.dynamodb.model.QueryConditional;

QueryConditional queryConditional = QueryConditional
    .keyEqualTo(Key.builder()
        .partitionValue(customerId)
        .build());

List<Order> orders = table.query(queryConditional).items().stream()
    .collect(Collectors.toList());

import software.amazon.awssdk.enhanced.dynamodb.Expression;

Expression filter = Expression.builder()
    .expression("status = :pending")
    .putExpressionValue(":pending", AttributeValue.builder().s("PENDING").build())
    .build();

List<Order> pendingOrders = table.query(r -> r
    .queryConditional(queryConditional)
    .filterExpression(filter))
    .items().stream()
    .collect(Collectors.toList());

// Scan all items
List<Customer> allCustomers = table.scan().items().stream()
    .collect(Collectors.toList());

// Scan with filter
Expression filter = Expression.builder()
    .expression("points >= :minPoints")
    .putExpressionValue(":minPoints", AttributeValue.builder().n("1000").build())
    .build();

List<Customer> vipCustomers = table.scan(r -> r.filterExpression(filter))
    .items().stream()
    .collect(Collectors.toList());

import software.amazon.awssdk.enhanced.dynamodb.model.*;

List<Key> keys = customerIds.stream()
    .map(id -> Key.builder().partitionValue(id).build())
    .collect(Collectors.toList());

ReadBatch.Builder<Customer> batchBuilder = ReadBatch.builder(Customer.class)
    .mappedTableResource(table);

keys.forEach(batchBuilder::addGetItem);

BatchGetResultPageIterable result = enhancedClient.batchGetItem(r ->
    r.addReadBatch(batchBuilder.build()));

List<Customer> customers = result.resultsForTable(table).stream()
    .collect(Collectors.toList());

WriteBatch.Builder<Customer> batchBuilder = WriteBatch.builder(Customer.class)
    .mappedTableResource(table);

customers.forEach(batchBuilder::addPutItem);

BatchWriteItemEnhancedRequest request = BatchWriteItemEnhancedRequest.builder()
    .addWriteBatch(batchBuilder.build())
    .build();

BatchWriteResult result = enhancedClient.batchWriteItem(request);

// Validate: check for unprocessed items
if (!result.writeResponsesForTable(table).isEmpty()) {
    // Retry unprocessed items with exponential backoff
    Map<String, AttributeValue> unprocessed = result.writeResponsesForTable(table).get(0)
        .unprocessedAttributes();
    if (unprocessed != null && !unprocessed.isEmpty()) {
        enhancedClient.batchWriteItem(r -> r
            .addWriteBatch(WriteBatch.builder(Customer.class)
                .mappedTableResource(table)
                .addPutItemFromItem(unprocessed)
                .build()));
    }
}

public void placeOrderWithRetry(Order order, Customer customer, int maxRetries) {
    int attempt = 0;
    while (attempt < maxRetries) {
        try {
            enhancedClient.transactWriteItems(r -> r
                .addPutItem(customerTable, customer)
                .addPutItem(orderTable, order));
            return;
        } catch (TransactionCanceledException e) {
            if (e.cancellationReasons().stream()
                .anyMatch(r -> r.code().equals("TransactionCanceledException")
                    && r.message().contains("throughput"))) {
                attempt++;
                if (attempt < maxRetries) {
                    try { Thread.sleep((long) Math.pow(2, attempt) * 100); }
                    catch (InterruptedException ie) { Thread.currentThread().interrupt(); }
                }
            } else {
                throw e; // Non-retryable error
            }
        }
    }
}

TransactGetItemsEnhancedRequest request = TransactGetItemsEnhancedRequest.builder()
    .addGetItem(customerTable, customerKey)
    .addGetItem(orderTable, orderKey)
    .build();

List<Document> results = enhancedClient.transactGetItems(request);

@Configuration
public class DynamoDbConfiguration {

    @Bean
    public DynamoDbClient dynamoDbClient() {
        return DynamoDbClient.builder()
            .region(Region.US_EAST_1)
            .build();
    }

    @Bean
    public DynamoDbEnhancedClient dynamoDbEnhancedClient(DynamoDbClient dynamoDbClient) {
        return DynamoDbEnhancedClient.builder()
            .dynamoDbClient(dynamoDbClient)
            .build();
    }
}

@Repository
public class CustomerRepository {

    private final DynamoDbTable<Customer> customerTable;

    public CustomerRepository(DynamoDbEnhancedClient enhancedClient) {
        this.customerTable = enhancedClient.table("Customers", TableSchema.fromBean(Customer.class));
    }

    public void save(Customer customer) {
        customerTable.putItem(customer);
    }

    public Optional<Customer> findById(String customerId) {
        Key key = Key.builder().partitionValue(customerId).build();
        return Optional.ofNullable(customerTable.getItem(key));
    }
}