使用適用於 Java 2.x 的 SDK 的 Amazon Keyspaces 範例 - AWS SDK 程式碼範例

文件 AWS 開發套件範例 GitHub 儲存庫中有更多可用的 AWS SDK 範例

本文為英文版的機器翻譯版本,如內容有任何歧義或不一致之處,概以英文版為準。

使用適用於 Java 2.x 的 SDK 的 Amazon Keyspaces 範例

下列程式碼範例示範如何使用 AWS SDK for Java 2.x 搭配 Amazon Keyspaces 來執行動作和實作常見案例。

基本概念是程式碼範例,這些範例說明如何在服務內執行基本操作。

Actions 是大型程式的程式碼摘錄,必須在內容中執行。雖然動作會告訴您如何呼叫個別服務函數,但您可以在其相關情境中查看內容中的動作。

每個範例都包含完整原始程式碼的連結,您可以在其中找到如何在內容中設定和執行程式碼的指示。

開始使用

下列程式碼範例說明如何開始使用 Amazon Keyspaces。

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } } }
  • 如需 API 詳細資訊,請參閱 AWS SDK for Java 2.x API 參考中的 ListKeyspaces

基本概念

以下程式碼範例顯示做法:

  • 建立金鑰空間和資料表。資料表結構描述會保留電影資料,並啟用point-in-time復原。

  • 使用具有 SigV4 身分驗證的安全 TLS 連線,連線至 金鑰空間。

  • 查詢資料表。新增、擷取和更新電影資料。

  • 更新資料表。新增資料欄以追蹤觀看的電影。

  • 將資料表還原至其先前的狀態並清除資源。

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

/** * 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); } } }

動作

下列程式碼範例示範如何使用 CreateKeyspace

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 詳細資訊,請參閱 AWS SDK for Java 2.x API 參考中的 CreateKeyspace

下列程式碼範例示範如何使用 CreateTable

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 的詳細資訊,請參閱《AWS SDK for Java 2.x API 參考》中的 CreateTable

下列程式碼範例示範如何使用 DeleteKeyspace

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 詳細資訊,請參閱 AWS SDK for Java 2.x API 參考中的 DeleteKeyspace

下列程式碼範例示範如何使用 DeleteTable

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 的詳細資訊,請參閱《AWS SDK for Java 2.x API 參考》中的 DeleteTable

下列程式碼範例示範如何使用 GetKeyspace

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 詳細資訊,請參閱 AWS SDK for Java 2.x API 參考中的 GetKeyspace

下列程式碼範例示範如何使用 GetTable

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 詳細資訊,請參閱 AWS SDK for Java 2.x API 參考中的 GetTable

下列程式碼範例示範如何使用 ListKeyspaces

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 詳細資訊,請參閱 AWS SDK for Java 2.x API 參考中的 ListKeyspaces

下列程式碼範例示範如何使用 ListTables

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 的詳細資訊,請參閱 AWS SDK for Java 2.x API 參考中的 ListTables

下列程式碼範例示範如何使用 RestoreTable

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 詳細資訊,請參閱 AWS SDK for Java 2.x API 參考中的 RestoreTable

下列程式碼範例示範如何使用 UpdateTable

SDK for Java 2.x
注意

GitHub 上提供更多範例。尋找完整範例,並了解如何在 AWS 程式碼範例儲存庫中設定和執行。

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); } }
  • 如需 API 詳細資訊,請參閱 AWS SDK for Java 2.x API 參考中的 UpdateTable