文档 AWS SDK 示例 GitHub 存储库中还有更多 [S AWS DK 示例](https://github.com/awsdocs/aws-doc-sdk-examples)。

本文属于机器翻译版本。若本译文内容与英语原文存在差异，则一律以英文原文为准。

# 使用 SDK for Java 2.x 的 Amazon Keyspaces 示例
<a name="java_2_keyspaces_code_examples"></a>

以下代码示例向您展示了如何使用 AWS SDK for Java 2.x 与 Amazon Keyspaces 配合使用来执行操作和实现常见场景。

*基本功能*是向您展示如何在服务中执行基本操作的代码示例。

*操作*是大型程序的代码摘录，必须在上下文中运行。您可以通过操作了解如何调用单个服务函数，还可以通过函数相关场景的上下文查看操作。

每个示例都包含一个指向完整源代码的链接，您可以从中找到有关如何在上下文中设置和运行代码的说明。

**Topics**
+ [开始使用](#get_started)
+ [基本功能](#basics)
+ [操作](#actions)

## 开始使用
<a name="get_started"></a>

### 开始使用 Amazon Keysp
<a name="keyspaces_Hello_java_2_topic"></a>

以下代码示例展示了如何开始使用 Amazon Keyspaces。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.keyspaces.KeyspacesClient;
import software.amazon.awssdk.services.keyspaces.model.KeyspaceSummary;
import software.amazon.awssdk.services.keyspaces.model.KeyspacesException;
import software.amazon.awssdk.services.keyspaces.model.ListKeyspacesRequest;
import software.amazon.awssdk.services.keyspaces.model.ListKeyspacesResponse;
import java.util.List;

/**
 * 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 HelloKeyspaces {
    public static void main(String[] args) {
        Region region = Region.US_EAST_1;
        KeyspacesClient keyClient = KeyspacesClient.builder()
                .region(region)
                .build();

        listKeyspaces(keyClient);
    }

    public static void listKeyspaces(KeyspacesClient keyClient) {
        try {
            ListKeyspacesRequest keyspacesRequest = ListKeyspacesRequest.builder()
                    .maxResults(10)
                    .build();

            ListKeyspacesResponse response = keyClient.listKeyspaces(keyspacesRequest);
            List<KeyspaceSummary> keyspaces = response.keyspaces();
            for (KeyspaceSummary keyspace : keyspaces) {
                System.out.println("The name of the keyspace is " + keyspace.keyspaceName());
            }

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
}
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[ListKeyspaces](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/ListKeyspaces)*中的。

## 基本功能
<a name="basics"></a>

### 了解基本功能
<a name="keyspaces_Scenario_GetStartedKeyspaces_java_2_topic"></a>

以下代码示例展示了如何：
+ 创建密钥空间和表。表架构保存电影数据并启用了 point-in-time恢复。
+ 使用带有 Sigv4 身份验证的安全 TLS 连接连接到密钥空间。
+ 查询表。添加、检索和更新电影数据。
+ 更新表。添加一列来跟踪观看的电影。
+ 将表还原到以前的状态并清理资源。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples) 中查找完整示例，了解如何进行设置和运行。

```
/**
 * 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
 *
 * Before running this Java code example, you must create a
 * Java keystore (JKS) file and place it in your project's resources folder.
 *
 * This file is a secure file format used to hold certificate information for
 * Java applications. This is required to make a connection to Amazon Keyspaces.
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/keyspaces/latest/devguide/using_java_driver.html
 *
 * This Java example performs the following tasks:
 *
 * 1. Create a keyspace.
 * 2. Check for keyspace existence.
 * 3. List keyspaces using a paginator.
 * 4. Create a table with a simple movie data schema and enable point-in-time
 * recovery.
 * 5. Check for the table to be in an Active state.
 * 6. List all tables in the keyspace.
 * 7. Use a Cassandra driver to insert some records into the Movie table.
 * 8. Get all records from the Movie table.
 * 9. Get a specific Movie.
 * 10. Get a UTC timestamp for the current time.
 * 11. Update the table schema to add a ‘watched’ Boolean column.
 * 12. Update an item as watched.
 * 13. Query for items with watched = True.
 * 14. Restore the table back to the previous state using the timestamp.
 * 15. Check for completion of the restore action.
 * 16. Delete the table.
 * 17. Confirm that both tables are deleted.
 * 18. Delete the keyspace.
 */

public class ScenarioKeyspaces {
    public static final String DASHES = new String(new char[80]).replace("\0", "-");

    /*
     * Usage:
     * fileName - The name of the JSON file that contains movie data. (Get this file
     * from the GitHub repo at resources/sample_file.)
     * keyspaceName - The name of the keyspace to create.
     */
    public static void main(String[] args) throws InterruptedException, IOException {
        String fileName = "<Replace with the JSON file that contains movie data>";
        String keyspaceName = "<Replace with the name of the keyspace to create>";
        String titleUpdate = "The Family";
        int yearUpdate = 2013;
        String tableName = "Movie";
        String tableNameRestore = "MovieRestore";
        Region region = Region.US_EAST_1;
        KeyspacesClient keyClient = KeyspacesClient.builder()
                .region(region)
                .build();

        DriverConfigLoader loader = DriverConfigLoader.fromClasspath("application.conf");
        CqlSession session = CqlSession.builder()
                .withConfigLoader(loader)
                .build();

        System.out.println(DASHES);
        System.out.println("Welcome to the Amazon Keyspaces example scenario.");
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("1. Create a keyspace.");
        createKeySpace(keyClient, keyspaceName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        Thread.sleep(5000);
        System.out.println("2. Check for keyspace existence.");
        checkKeyspaceExistence(keyClient, keyspaceName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("3. List keyspaces using a paginator.");
        listKeyspacesPaginator(keyClient);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("4. Create a table with a simple movie data schema and enable point-in-time recovery.");
        createTable(keyClient, keyspaceName, tableName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("5. Check for the table to be in an Active state.");
        Thread.sleep(6000);
        checkTable(keyClient, keyspaceName, tableName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("6. List all tables in the keyspace.");
        listTables(keyClient, keyspaceName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("7. Use a Cassandra driver to insert some records into the Movie table.");
        Thread.sleep(6000);
        loadData(session, fileName, keyspaceName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("8. Get all records from the Movie table.");
        getMovieData(session, keyspaceName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("9. Get a specific Movie.");
        getSpecificMovie(session, keyspaceName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("10. Get a UTC timestamp for the current time.");
        ZonedDateTime utc = ZonedDateTime.now(ZoneOffset.UTC);
        System.out.println("DATETIME = " + Date.from(utc.toInstant()));
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("11. Update the table schema to add a watched Boolean column.");
        updateTable(keyClient, keyspaceName, tableName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("12. Update an item as watched.");
        Thread.sleep(10000); // Wait 10 secs for the update.
        updateRecord(session, keyspaceName, titleUpdate, yearUpdate);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("13. Query for items with watched = True.");
        getWatchedData(session, keyspaceName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("14. Restore the table back to the previous state using the timestamp.");
        System.out.println("Note that the restore operation can take up to 20 minutes.");
        restoreTable(keyClient, keyspaceName, utc);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("15. Check for completion of the restore action.");
        Thread.sleep(5000);
        checkRestoredTable(keyClient, keyspaceName, "MovieRestore");
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("16. Delete both tables.");
        deleteTable(keyClient, keyspaceName, tableName);
        deleteTable(keyClient, keyspaceName, tableNameRestore);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("17. Confirm that both tables are deleted.");
        checkTableDelete(keyClient, keyspaceName, tableName);
        checkTableDelete(keyClient, keyspaceName, tableNameRestore);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("18. Delete the keyspace.");
        deleteKeyspace(keyClient, keyspaceName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("The scenario has completed successfully.");
        System.out.println(DASHES);
    }

    public static void deleteKeyspace(KeyspacesClient keyClient, String keyspaceName) {
        try {
            DeleteKeyspaceRequest deleteKeyspaceRequest = DeleteKeyspaceRequest.builder()
                    .keyspaceName(keyspaceName)
                    .build();

            keyClient.deleteKeyspace(deleteKeyspaceRequest);

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void checkTableDelete(KeyspacesClient keyClient, String keyspaceName, String tableName)
            throws InterruptedException {
        try {
            String status;
            GetTableResponse response;
            GetTableRequest tableRequest = GetTableRequest.builder()
                    .keyspaceName(keyspaceName)
                    .tableName(tableName)
                    .build();

            // Keep looping until table cannot be found and a ResourceNotFoundException is
            // thrown.
            while (true) {
                response = keyClient.getTable(tableRequest);
                status = response.statusAsString();
                System.out.println(". The table status is " + status);
                Thread.sleep(500);
            }

        } catch (ResourceNotFoundException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
        }
        System.out.println("The table is deleted");
    }

    public static void deleteTable(KeyspacesClient keyClient, String keyspaceName, String tableName) {
        try {
            DeleteTableRequest tableRequest = DeleteTableRequest.builder()
                    .keyspaceName(keyspaceName)
                    .tableName(tableName)
                    .build();

            keyClient.deleteTable(tableRequest);

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void checkRestoredTable(KeyspacesClient keyClient, String keyspaceName, String tableName)
            throws InterruptedException {
        try {
            boolean tableStatus = false;
            String status;
            GetTableResponse response = null;
            GetTableRequest tableRequest = GetTableRequest.builder()
                    .keyspaceName(keyspaceName)
                    .tableName(tableName)
                    .build();

            while (!tableStatus) {
                response = keyClient.getTable(tableRequest);
                status = response.statusAsString();
                System.out.println("The table status is " + status);

                if (status.compareTo("ACTIVE") == 0) {
                    tableStatus = true;
                }
                Thread.sleep(500);
            }

            List<ColumnDefinition> cols = response.schemaDefinition().allColumns();
            for (ColumnDefinition def : cols) {
                System.out.println("The column name is " + def.name());
                System.out.println("The column type is " + def.type());
            }

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void restoreTable(KeyspacesClient keyClient, String keyspaceName, ZonedDateTime utc) {
        try {
            Instant myTime = utc.toInstant();
            RestoreTableRequest restoreTableRequest = RestoreTableRequest.builder()
                    .restoreTimestamp(myTime)
                    .sourceTableName("Movie")
                    .targetKeyspaceName(keyspaceName)
                    .targetTableName("MovieRestore")
                    .sourceKeyspaceName(keyspaceName)
                    .build();

            RestoreTableResponse response = keyClient.restoreTable(restoreTableRequest);
            System.out.println("The ARN of the restored table is " + response.restoredTableARN());

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void getWatchedData(CqlSession session, String keyspaceName) {
        ResultSet resultSet = session
                .execute("SELECT * FROM \"" + keyspaceName + "\".\"Movie\" WHERE watched = true ALLOW FILTERING;");
        resultSet.forEach(item -> {
            System.out.println("The Movie title is " + item.getString("title"));
            System.out.println("The Movie year is " + item.getInt("year"));
            System.out.println("The plot is " + item.getString("plot"));
        });
    }

    public static void updateRecord(CqlSession session, String keySpace, String titleUpdate, int yearUpdate) {
        String sqlStatement = "UPDATE \"" + keySpace
                + "\".\"Movie\" SET watched=true WHERE title = :k0 AND year = :k1;";
        BatchStatementBuilder builder = BatchStatement.builder(DefaultBatchType.UNLOGGED);
        builder.setConsistencyLevel(ConsistencyLevel.LOCAL_QUORUM);
        PreparedStatement preparedStatement = session.prepare(sqlStatement);
        builder.addStatement(preparedStatement.boundStatementBuilder()
                .setString("k0", titleUpdate)
                .setInt("k1", yearUpdate)
                .build());

        BatchStatement batchStatement = builder.build();
        session.execute(batchStatement);
    }

    public static void updateTable(KeyspacesClient keyClient, String keySpace, String tableName) {
        try {
            ColumnDefinition def = ColumnDefinition.builder()
                    .name("watched")
                    .type("boolean")
                    .build();

            UpdateTableRequest tableRequest = UpdateTableRequest.builder()
                    .keyspaceName(keySpace)
                    .tableName(tableName)
                    .addColumns(def)
                    .build();

            keyClient.updateTable(tableRequest);

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void getSpecificMovie(CqlSession session, String keyspaceName) {
        ResultSet resultSet = session.execute(
                "SELECT * FROM \"" + keyspaceName + "\".\"Movie\" WHERE title = 'The Family' ALLOW FILTERING ;");
        resultSet.forEach(item -> {
            System.out.println("The Movie title is " + item.getString("title"));
            System.out.println("The Movie year is " + item.getInt("year"));
            System.out.println("The plot is " + item.getString("plot"));
        });
    }

    // Get records from the Movie table.
    public static void getMovieData(CqlSession session, String keyspaceName) {
        ResultSet resultSet = session.execute("SELECT * FROM \"" + keyspaceName + "\".\"Movie\";");
        resultSet.forEach(item -> {
            System.out.println("The Movie title is " + item.getString("title"));
            System.out.println("The Movie year is " + item.getInt("year"));
            System.out.println("The plot is " + item.getString("plot"));
        });
    }

    // Load data into the table.
    public static void loadData(CqlSession session, String fileName, String keySpace) throws IOException {
        String sqlStatement = "INSERT INTO \"" + keySpace + "\".\"Movie\" (title, year, plot) values (:k0, :k1, :k2)";
        JsonParser parser = new JsonFactory().createParser(new File(fileName));
        com.fasterxml.jackson.databind.JsonNode rootNode = new ObjectMapper().readTree(parser);
        Iterator<JsonNode> iter = rootNode.iterator();
        ObjectNode currentNode;
        int t = 0;
        while (iter.hasNext()) {

            // Add 20 movies to the table.
            if (t == 20)
                break;
            currentNode = (ObjectNode) iter.next();

            int year = currentNode.path("year").asInt();
            String title = currentNode.path("title").asText();
            String plot = currentNode.path("info").path("plot").toString();

            // Insert the data into the Amazon Keyspaces table.
            BatchStatementBuilder builder = BatchStatement.builder(DefaultBatchType.UNLOGGED);
            builder.setConsistencyLevel(ConsistencyLevel.LOCAL_QUORUM);
            PreparedStatement preparedStatement = session.prepare(sqlStatement);
            builder.addStatement(preparedStatement.boundStatementBuilder()
                    .setString("k0", title)
                    .setInt("k1", year)
                    .setString("k2", plot)
                    .build());

            BatchStatement batchStatement = builder.build();
            session.execute(batchStatement);
            t++;
        }

        System.out.println("You have added " + t + " records successfully!");
    }

    public static void listTables(KeyspacesClient keyClient, String keyspaceName) {
        try {
            ListTablesRequest tablesRequest = ListTablesRequest.builder()
                    .keyspaceName(keyspaceName)
                    .build();

            ListTablesIterable listRes = keyClient.listTablesPaginator(tablesRequest);
            listRes.stream()
                    .flatMap(r -> r.tables().stream())
                    .forEach(content -> System.out.println(" ARN: " + content.resourceArn() +
                            " Table name: " + content.tableName()));

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void checkTable(KeyspacesClient keyClient, String keyspaceName, String tableName)
            throws InterruptedException {
        try {
            boolean tableStatus = false;
            String status;
            GetTableResponse response = null;
            GetTableRequest tableRequest = GetTableRequest.builder()
                    .keyspaceName(keyspaceName)
                    .tableName(tableName)
                    .build();

            while (!tableStatus) {
                response = keyClient.getTable(tableRequest);
                status = response.statusAsString();
                System.out.println(". The table status is " + status);

                if (status.compareTo("ACTIVE") == 0) {
                    tableStatus = true;
                }
                Thread.sleep(500);
            }

            List<ColumnDefinition> cols = response.schemaDefinition().allColumns();
            for (ColumnDefinition def : cols) {
                System.out.println("The column name is " + def.name());
                System.out.println("The column type is " + def.type());
            }

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void createTable(KeyspacesClient keyClient, String keySpace, String tableName) {
        try {
            // Set the columns.
            ColumnDefinition defTitle = ColumnDefinition.builder()
                    .name("title")
                    .type("text")
                    .build();

            ColumnDefinition defYear = ColumnDefinition.builder()
                    .name("year")
                    .type("int")
                    .build();

            ColumnDefinition defReleaseDate = ColumnDefinition.builder()
                    .name("release_date")
                    .type("timestamp")
                    .build();

            ColumnDefinition defPlot = ColumnDefinition.builder()
                    .name("plot")
                    .type("text")
                    .build();

            List<ColumnDefinition> colList = new ArrayList<>();
            colList.add(defTitle);
            colList.add(defYear);
            colList.add(defReleaseDate);
            colList.add(defPlot);

            // Set the keys.
            PartitionKey yearKey = PartitionKey.builder()
                    .name("year")
                    .build();

            PartitionKey titleKey = PartitionKey.builder()
                    .name("title")
                    .build();

            List<PartitionKey> keyList = new ArrayList<>();
            keyList.add(yearKey);
            keyList.add(titleKey);

            SchemaDefinition schemaDefinition = SchemaDefinition.builder()
                    .partitionKeys(keyList)
                    .allColumns(colList)
                    .build();

            PointInTimeRecovery timeRecovery = PointInTimeRecovery.builder()
                    .status(PointInTimeRecoveryStatus.ENABLED)
                    .build();

            CreateTableRequest tableRequest = CreateTableRequest.builder()
                    .keyspaceName(keySpace)
                    .tableName(tableName)
                    .schemaDefinition(schemaDefinition)
                    .pointInTimeRecovery(timeRecovery)
                    .build();

            CreateTableResponse response = keyClient.createTable(tableRequest);
            System.out.println("The table ARN is " + response.resourceArn());

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void listKeyspacesPaginator(KeyspacesClient keyClient) {
        try {
            ListKeyspacesRequest keyspacesRequest = ListKeyspacesRequest.builder()
                    .maxResults(10)
                    .build();

            ListKeyspacesIterable listRes = keyClient.listKeyspacesPaginator(keyspacesRequest);
            listRes.stream()
                    .flatMap(r -> r.keyspaces().stream())
                    .forEach(content -> System.out.println(" Name: " + content.keyspaceName()));

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void checkKeyspaceExistence(KeyspacesClient keyClient, String keyspaceName) {
        try {
            GetKeyspaceRequest keyspaceRequest = GetKeyspaceRequest.builder()
                    .keyspaceName(keyspaceName)
                    .build();

            GetKeyspaceResponse response = keyClient.getKeyspace(keyspaceRequest);
            String name = response.keyspaceName();
            System.out.println("The " + name + " KeySpace is ready");

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

    public static void createKeySpace(KeyspacesClient keyClient, String keyspaceName) {
        try {
            CreateKeyspaceRequest keyspaceRequest = CreateKeyspaceRequest.builder()
                    .keyspaceName(keyspaceName)
                    .build();

            CreateKeyspaceResponse response = keyClient.createKeyspace(keyspaceRequest);
            System.out.println("The ARN of the KeySpace is " + response.resourceArn());

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的以下主题。
  + [CreateKeyspace](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/CreateKeyspace)
  + [CreateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/CreateTable)
  + [DeleteKeyspace](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/DeleteKeyspace)
  + [DeleteTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/DeleteTable)
  + [GetKeyspace](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/GetKeyspace)
  + [GetTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/GetTable)
  + [ListKeyspaces](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/ListKeyspaces)
  + [ListTables](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/ListTables)
  + [RestoreTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/RestoreTable)
  + [UpdateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/UpdateTable)

## 操作
<a name="actions"></a>

### `CreateKeyspace`
<a name="keyspaces_CreateKeyspace_java_2_topic"></a>

以下代码示例演示了如何使用 `CreateKeyspace`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void createKeySpace(KeyspacesClient keyClient, String keyspaceName) {
        try {
            CreateKeyspaceRequest keyspaceRequest = CreateKeyspaceRequest.builder()
                    .keyspaceName(keyspaceName)
                    .build();

            CreateKeyspaceResponse response = keyClient.createKeyspace(keyspaceRequest);
            System.out.println("The ARN of the KeySpace is " + response.resourceArn());

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[CreateKeyspace](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/CreateKeyspace)*中的。

### `CreateTable`
<a name="keyspaces_CreateTable_java_2_topic"></a>

以下代码示例演示了如何使用 `CreateTable`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void createTable(KeyspacesClient keyClient, String keySpace, String tableName) {
        try {
            // Set the columns.
            ColumnDefinition defTitle = ColumnDefinition.builder()
                    .name("title")
                    .type("text")
                    .build();

            ColumnDefinition defYear = ColumnDefinition.builder()
                    .name("year")
                    .type("int")
                    .build();

            ColumnDefinition defReleaseDate = ColumnDefinition.builder()
                    .name("release_date")
                    .type("timestamp")
                    .build();

            ColumnDefinition defPlot = ColumnDefinition.builder()
                    .name("plot")
                    .type("text")
                    .build();

            List<ColumnDefinition> colList = new ArrayList<>();
            colList.add(defTitle);
            colList.add(defYear);
            colList.add(defReleaseDate);
            colList.add(defPlot);

            // Set the keys.
            PartitionKey yearKey = PartitionKey.builder()
                    .name("year")
                    .build();

            PartitionKey titleKey = PartitionKey.builder()
                    .name("title")
                    .build();

            List<PartitionKey> keyList = new ArrayList<>();
            keyList.add(yearKey);
            keyList.add(titleKey);

            SchemaDefinition schemaDefinition = SchemaDefinition.builder()
                    .partitionKeys(keyList)
                    .allColumns(colList)
                    .build();

            PointInTimeRecovery timeRecovery = PointInTimeRecovery.builder()
                    .status(PointInTimeRecoveryStatus.ENABLED)
                    .build();

            CreateTableRequest tableRequest = CreateTableRequest.builder()
                    .keyspaceName(keySpace)
                    .tableName(tableName)
                    .schemaDefinition(schemaDefinition)
                    .pointInTimeRecovery(timeRecovery)
                    .build();

            CreateTableResponse response = keyClient.createTable(tableRequest);
            System.out.println("The table ARN is " + response.resourceArn());

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[CreateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/CreateTable)*中的。

### `DeleteKeyspace`
<a name="keyspaces_DeleteKeyspace_java_2_topic"></a>

以下代码示例演示了如何使用 `DeleteKeyspace`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void deleteKeyspace(KeyspacesClient keyClient, String keyspaceName) {
        try {
            DeleteKeyspaceRequest deleteKeyspaceRequest = DeleteKeyspaceRequest.builder()
                    .keyspaceName(keyspaceName)
                    .build();

            keyClient.deleteKeyspace(deleteKeyspaceRequest);

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[DeleteKeyspace](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/DeleteKeyspace)*中的。

### `DeleteTable`
<a name="keyspaces_DeleteTable_java_2_topic"></a>

以下代码示例演示了如何使用 `DeleteTable`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void deleteTable(KeyspacesClient keyClient, String keyspaceName, String tableName) {
        try {
            DeleteTableRequest tableRequest = DeleteTableRequest.builder()
                    .keyspaceName(keyspaceName)
                    .tableName(tableName)
                    .build();

            keyClient.deleteTable(tableRequest);

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[DeleteTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/DeleteTable)*中的。

### `GetKeyspace`
<a name="keyspaces_GetKeyspace_java_2_topic"></a>

以下代码示例演示了如何使用 `GetKeyspace`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void checkKeyspaceExistence(KeyspacesClient keyClient, String keyspaceName) {
        try {
            GetKeyspaceRequest keyspaceRequest = GetKeyspaceRequest.builder()
                    .keyspaceName(keyspaceName)
                    .build();

            GetKeyspaceResponse response = keyClient.getKeyspace(keyspaceRequest);
            String name = response.keyspaceName();
            System.out.println("The " + name + " KeySpace is ready");

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[GetKeyspace](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/GetKeyspace)*中的。

### `GetTable`
<a name="keyspaces_GetTable_java_2_topic"></a>

以下代码示例演示了如何使用 `GetTable`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void checkTable(KeyspacesClient keyClient, String keyspaceName, String tableName)
            throws InterruptedException {
        try {
            boolean tableStatus = false;
            String status;
            GetTableResponse response = null;
            GetTableRequest tableRequest = GetTableRequest.builder()
                    .keyspaceName(keyspaceName)
                    .tableName(tableName)
                    .build();

            while (!tableStatus) {
                response = keyClient.getTable(tableRequest);
                status = response.statusAsString();
                System.out.println(". The table status is " + status);

                if (status.compareTo("ACTIVE") == 0) {
                    tableStatus = true;
                }
                Thread.sleep(500);
            }

            List<ColumnDefinition> cols = response.schemaDefinition().allColumns();
            for (ColumnDefinition def : cols) {
                System.out.println("The column name is " + def.name());
                System.out.println("The column type is " + def.type());
            }

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[GetTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/GetTable)*中的。

### `ListKeyspaces`
<a name="keyspaces_ListKeyspaces_java_2_topic"></a>

以下代码示例演示了如何使用 `ListKeyspaces`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void listKeyspacesPaginator(KeyspacesClient keyClient) {
        try {
            ListKeyspacesRequest keyspacesRequest = ListKeyspacesRequest.builder()
                    .maxResults(10)
                    .build();

            ListKeyspacesIterable listRes = keyClient.listKeyspacesPaginator(keyspacesRequest);
            listRes.stream()
                    .flatMap(r -> r.keyspaces().stream())
                    .forEach(content -> System.out.println(" Name: " + content.keyspaceName()));

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[ListKeyspaces](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/ListKeyspaces)*中的。

### `ListTables`
<a name="keyspaces_ListTables_java_2_topic"></a>

以下代码示例演示了如何使用 `ListTables`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void listTables(KeyspacesClient keyClient, String keyspaceName) {
        try {
            ListTablesRequest tablesRequest = ListTablesRequest.builder()
                    .keyspaceName(keyspaceName)
                    .build();

            ListTablesIterable listRes = keyClient.listTablesPaginator(tablesRequest);
            listRes.stream()
                    .flatMap(r -> r.tables().stream())
                    .forEach(content -> System.out.println(" ARN: " + content.resourceArn() +
                            " Table name: " + content.tableName()));

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[ListTables](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/ListTables)*中的。

### `RestoreTable`
<a name="keyspaces_RestoreTable_java_2_topic"></a>

以下代码示例演示了如何使用 `RestoreTable`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void restoreTable(KeyspacesClient keyClient, String keyspaceName, ZonedDateTime utc) {
        try {
            Instant myTime = utc.toInstant();
            RestoreTableRequest restoreTableRequest = RestoreTableRequest.builder()
                    .restoreTimestamp(myTime)
                    .sourceTableName("Movie")
                    .targetKeyspaceName(keyspaceName)
                    .targetTableName("MovieRestore")
                    .sourceKeyspaceName(keyspaceName)
                    .build();

            RestoreTableResponse response = keyClient.restoreTable(restoreTableRequest);
            System.out.println("The ARN of the restored table is " + response.restoredTableARN());

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[RestoreTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/RestoreTable)*中的。

### `UpdateTable`
<a name="keyspaces_UpdateTable_java_2_topic"></a>

以下代码示例演示了如何使用 `UpdateTable`。

**适用于 Java 的 SDK 2.x**  
 还有更多相关信息 GitHub。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/keyspaces#code-examples)中查找完整示例，了解如何进行设置和运行。

```
    public static void updateTable(KeyspacesClient keyClient, String keySpace, String tableName) {
        try {
            ColumnDefinition def = ColumnDefinition.builder()
                    .name("watched")
                    .type("boolean")
                    .build();

            UpdateTableRequest tableRequest = UpdateTableRequest.builder()
                    .keyspaceName(keySpace)
                    .tableName(tableName)
                    .addColumns(def)
                    .build();

            keyClient.updateTable(tableRequest);

        } catch (KeyspacesException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
```
+  有关 API 的详细信息，请参阅 *AWS SDK for Java 2.x API 参考[UpdateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/keyspaces-2022-02-10/UpdateTable)*中的。