Weitere AWS SDK-Beispiele sind im GitHub Repo [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) verfügbar.
Die vorliegende Übersetzung wurde maschinell erstellt. Im Falle eines Konflikts oder eines Widerspruchs zwischen dieser übersetzten Fassung und der englischen Fassung (einschließlich infolge von Verzögerungen bei der Übersetzung) ist die englische Fassung maßgeblich.
# Erstellen und verwalten Sie globale DynamoDB-Tabellen zur Demonstration von MREC mithilfe eines SDK AWS
Im folgenden Codebeispiel wird gezeigt, wie globale DynamoDB-Tabellen mit Replikaten in mehreren Regionen erstellt und verwaltet werden.
+ Erstellen Sie eine Tabelle mit einem globalen sekundären Index und DynamoDB Streams.
+ Fügen Sie Replikate in verschiedenen Regionen hinzu, um eine globale Tabelle zu erstellen.
+ Entfernen Sie Replikate aus einer globalen Tabelle.
+ Fügen Sie Testelemente hinzu, um die regionsübergreifende Replikation zu überprüfen.
+ Beschreiben Sie die globale Tabellenkonfiguration und den Replikatstatus.
------
#### [ Java ]
**SDK für Java 2.x**
Erstellen Sie eine Tabelle mit Global Secondary Index und DynamoDB Streams mithilfe von. AWS SDK for Java 2.x
```
public static CreateTableResponse createTableWithGSI(
final DynamoDbClient dynamoDbClient, final String tableName, final String indexName) {
if (dynamoDbClient == null) {
throw new IllegalArgumentException("DynamoDB client cannot be null");
}
if (tableName == null || tableName.trim().isEmpty()) {
throw new IllegalArgumentException("Table name cannot be null or empty");
}
if (indexName == null || indexName.trim().isEmpty()) {
throw new IllegalArgumentException("Index name cannot be null or empty");
}
try {
LOGGER.info("Creating table: " + tableName + " with GSI: " + indexName);
CreateTableRequest createTableRequest = CreateTableRequest.builder()
.tableName(tableName)
.attributeDefinitions(
AttributeDefinition.builder()
.attributeName("Artist")
.attributeType(ScalarAttributeType.S)
.build(),
AttributeDefinition.builder()
.attributeName("SongTitle")
.attributeType(ScalarAttributeType.S)
.build())
.keySchema(
KeySchemaElement.builder()
.attributeName("Artist")
.keyType(KeyType.HASH)
.build(),
KeySchemaElement.builder()
.attributeName("SongTitle")
.keyType(KeyType.RANGE)
.build())
.billingMode(BillingMode.PAY_PER_REQUEST)
.globalSecondaryIndexes(GlobalSecondaryIndex.builder()
.indexName(indexName)
.keySchema(KeySchemaElement.builder()
.attributeName("SongTitle")
.keyType(KeyType.HASH)
.build())
.projection(
Projection.builder().projectionType(ProjectionType.ALL).build())
.build())
.streamSpecification(StreamSpecification.builder()
.streamEnabled(true)
.streamViewType(StreamViewType.NEW_AND_OLD_IMAGES)
.build())
.build();
CreateTableResponse response = dynamoDbClient.createTable(createTableRequest);
LOGGER.info("Table creation initiated. Status: "
+ response.tableDescription().tableStatus());
return response;
} catch (DynamoDbException e) {
LOGGER.severe("Failed to create table: " + tableName + " - " + e.getMessage());
throw e;
}
}
```
Warten Sie, bis eine Tabelle aktiv wird mit. AWS SDK for Java 2.x
```
public static void waitForTableActive(final DynamoDbClient dynamoDbClient, final String tableName) {
if (dynamoDbClient == null) {
throw new IllegalArgumentException("DynamoDB client cannot be null");
}
if (tableName == null || tableName.trim().isEmpty()) {
throw new IllegalArgumentException("Table name cannot be null or empty");
}
try {
LOGGER.info("Waiting for table to become active: " + tableName);
try (DynamoDbWaiter waiter =
DynamoDbWaiter.builder().client(dynamoDbClient).build()) {
DescribeTableRequest request =
DescribeTableRequest.builder().tableName(tableName).build();
waiter.waitUntilTableExists(request);
LOGGER.info("Table is now active: " + tableName);
}
} catch (DynamoDbException e) {
LOGGER.severe("Failed to wait for table to become active: " + tableName + " - " + e.getMessage());
throw e;
}
}
```
Fügen Sie ein Replikat hinzu, um eine globale Tabelle zu erstellen oder zu erweitern mit AWS SDK for Java 2.x.
```
public static UpdateTableResponse addReplica(
final DynamoDbClient dynamoDbClient,
final String tableName,
final Region replicaRegion,
final String indexName,
final Long readCapacity) {
if (dynamoDbClient == null) {
throw new IllegalArgumentException("DynamoDB client cannot be null");
}
if (tableName == null || tableName.trim().isEmpty()) {
throw new IllegalArgumentException("Table name cannot be null or empty");
}
if (replicaRegion == null) {
throw new IllegalArgumentException("Replica region cannot be null");
}
if (indexName == null || indexName.trim().isEmpty()) {
throw new IllegalArgumentException("Index name cannot be null or empty");
}
if (readCapacity == null || readCapacity <= 0) {
throw new IllegalArgumentException("Read capacity must be a positive number");
}
try {
LOGGER.info("Adding replica in region: " + replicaRegion.id() + " for table: " + tableName);
// Create a ReplicationGroupUpdate for adding a replica
ReplicationGroupUpdate replicationGroupUpdate = ReplicationGroupUpdate.builder()
.create(builder -> builder.regionName(replicaRegion.id())
.globalSecondaryIndexes(ReplicaGlobalSecondaryIndex.builder()
.indexName(indexName)
.provisionedThroughputOverride(ProvisionedThroughputOverride.builder()
.readCapacityUnits(readCapacity)
.build())
.build())
.build())
.build();
UpdateTableRequest updateTableRequest = UpdateTableRequest.builder()
.tableName(tableName)
.replicaUpdates(replicationGroupUpdate)
.build();
UpdateTableResponse response = dynamoDbClient.updateTable(updateTableRequest);
LOGGER.info("Replica addition initiated in region: " + replicaRegion.id());
return response;
} catch (DynamoDbException e) {
LOGGER.severe("Failed to add replica in region: " + replicaRegion.id() + " - " + e.getMessage());
throw e;
}
}
```
Entfernen Sie ein Replikat aus einer globalen Tabelle mit. AWS SDK for Java 2.x
```
public static UpdateTableResponse removeReplica(
final DynamoDbClient dynamoDbClient, final String tableName, final Region replicaRegion) {
if (dynamoDbClient == null) {
throw new IllegalArgumentException("DynamoDB client cannot be null");
}
if (tableName == null || tableName.trim().isEmpty()) {
throw new IllegalArgumentException("Table name cannot be null or empty");
}
if (replicaRegion == null) {
throw new IllegalArgumentException("Replica region cannot be null");
}
try {
LOGGER.info("Removing replica in region: " + replicaRegion.id() + " for table: " + tableName);
// Create a ReplicationGroupUpdate for removing a replica
ReplicationGroupUpdate replicationGroupUpdate = ReplicationGroupUpdate.builder()
.delete(builder -> builder.regionName(replicaRegion.id()).build())
.build();
UpdateTableRequest updateTableRequest = UpdateTableRequest.builder()
.tableName(tableName)
.replicaUpdates(replicationGroupUpdate)
.build();
UpdateTableResponse response = dynamoDbClient.updateTable(updateTableRequest);
LOGGER.info("Replica removal initiated in region: " + replicaRegion.id());
return response;
} catch (DynamoDbException e) {
LOGGER.severe("Failed to remove replica in region: " + replicaRegion.id() + " - " + e.getMessage());
throw e;
}
}
```
Fügen Sie Testelemente hinzu, um die Replikation mithilfe von AWS SDK for Java 2.x zu überprüfen.
```
public static PutItemResponse putTestItem(
final DynamoDbClient dynamoDbClient, final String tableName, final String artist, final String songTitle) {
if (dynamoDbClient == null) {
throw new IllegalArgumentException("DynamoDB client cannot be null");
}
if (tableName == null || tableName.trim().isEmpty()) {
throw new IllegalArgumentException("Table name cannot be null or empty");
}
if (artist == null || artist.trim().isEmpty()) {
throw new IllegalArgumentException("Artist cannot be null or empty");
}
if (songTitle == null || songTitle.trim().isEmpty()) {
throw new IllegalArgumentException("Song title cannot be null or empty");
}
try {
LOGGER.info("Adding test item to table: " + tableName);
Map item = new HashMap<>();
item.put(
"Artist",
software.amazon.awssdk.services.dynamodb.model.AttributeValue.builder()
.s(artist)
.build());
item.put(
"SongTitle",
software.amazon.awssdk.services.dynamodb.model.AttributeValue.builder()
.s(songTitle)
.build());
PutItemRequest putItemRequest =
PutItemRequest.builder().tableName(tableName).item(item).build();
PutItemResponse response = dynamoDbClient.putItem(putItemRequest);
LOGGER.info("Test item added successfully");
return response;
} catch (DynamoDbException e) {
LOGGER.severe("Failed to add test item to table: " + tableName + " - " + e.getMessage());
throw e;
}
}
```
Beschreiben Sie die globale Tabellenkonfiguration und die Verwendung von AWS SDK for Java 2.x Replikaten.
```
public static DescribeTableResponse describeTable(final DynamoDbClient dynamoDbClient, final String tableName) {
if (dynamoDbClient == null) {
throw new IllegalArgumentException("DynamoDB client cannot be null");
}
if (tableName == null || tableName.trim().isEmpty()) {
throw new IllegalArgumentException("Table name cannot be null or empty");
}
try {
LOGGER.info("Describing table: " + tableName);
DescribeTableRequest request =
DescribeTableRequest.builder().tableName(tableName).build();
DescribeTableResponse response = dynamoDbClient.describeTable(request);
LOGGER.info("Table status: " + response.table().tableStatus());
if (response.table().replicas() != null
&& !response.table().replicas().isEmpty()) {
LOGGER.info("Number of replicas: " + response.table().replicas().size());
response.table()
.replicas()
.forEach(replica -> LOGGER.info(
"Replica region: " + replica.regionName() + ", Status: " + replica.replicaStatus()));
}
return response;
} catch (ResourceNotFoundException e) {
LOGGER.severe("Table not found: " + tableName + " - " + e.getMessage());
throw e;
} catch (DynamoDbException e) {
LOGGER.severe("Failed to describe table: " + tableName + " - " + e.getMessage());
throw e;
}
}
```
Vollständiges Beispiel für globale Tabellenoperationen unter Verwendung von AWS SDK for Java 2.x.
```
public static void exampleUsage(final Region sourceRegion, final Region replicaRegion) {
String tableName = "Music";
String indexName = "SongTitleIndex";
Long readCapacity = 15L;
// Create DynamoDB client for the source region
try (DynamoDbClient dynamoDbClient =
DynamoDbClient.builder().region(sourceRegion).build()) {
try {
// Step 1: Create the initial table with GSI and streams
LOGGER.info("Step 1: Creating table in source region: " + sourceRegion.id());
createTableWithGSI(dynamoDbClient, tableName, indexName);
// Step 2: Wait for table to become active
LOGGER.info("Step 2: Waiting for table to become active");
waitForTableActive(dynamoDbClient, tableName);
// Step 3: Add replica in destination region
LOGGER.info("Step 3: Adding replica in region: " + replicaRegion.id());
addReplica(dynamoDbClient, tableName, replicaRegion, indexName, readCapacity);
// Step 4: Wait a moment for replica creation to start
Thread.sleep(5000);
// Step 5: Describe table to view replica information
LOGGER.info("Step 5: Describing table to view replicas");
describeTable(dynamoDbClient, tableName);
// Step 6: Add a test item to verify replication
LOGGER.info("Step 6: Adding test item to verify replication");
putTestItem(dynamoDbClient, tableName, "TestArtist", "TestSong");
LOGGER.info("Global table setup completed successfully!");
LOGGER.info("You can verify replication by checking the item in region: " + replicaRegion.id());
// Step 7: Remove replica and clean up table
LOGGER.info("Step 7: Removing replica from region: " + replicaRegion.id());
removeReplica(dynamoDbClient, tableName, replicaRegion);
DeleteTableResponse deleteTableResponse = dynamoDbClient.deleteTable(
DeleteTableRequest.builder().tableName(tableName).build());
LOGGER.info("MREC global table demonstration completed successfully!");
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new RuntimeException("Thread was interrupted", e);
} catch (DynamoDbException e) {
LOGGER.severe("DynamoDB operation failed: " + e.getMessage());
throw e;
}
}
}
```
+ Weitere API-Informationen finden Sie in den folgenden Themen der *AWS SDK for Java 2.x -API-Referenz*.
+ [CreateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/CreateTable)
+ [DescribeTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DescribeTable)
+ [PutItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/PutItem)
+ [UpdateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/UpdateTable)
------