使用 SDK for Kotlin 的 Amazon Keyspaces 範例 - AWS SDK 程式碼範例

文件範例儲存庫中有更多 AWS SDK可用的範例。 AWS SDK GitHub

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 SDK for Kotlin 的 Amazon Keyspaces 範例

下列程式碼範例示範如何使用 for Kotlin 搭配 AWS SDKAmazon Keyspaces 來執行動作和實作常見案例。

基本知識是程式碼範例,示範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。雖然動作會示範如何呼叫個別服務函數,但您可以在其相關案例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 適用於 Kotlin
注意

還有更多 。 GitHub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 Kotlin 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-kotlin/latest/developer-guide/setup.html */ suspend fun main() { listKeyspaces() } suspend fun listKeyspaces() { val keyspacesRequest = ListKeyspacesRequest { maxResults = 10 } KeyspacesClient { region = "us-east-1" }.use { keyClient -> val response = keyClient.listKeyspaces(keyspacesRequest) response.keyspaces?.forEach { keyspace -> println("The name of the keyspace is ${keyspace.keyspaceName}") } } }
  • 如需API詳細資訊,請參閱ListKeyspaces中的 AWS SDK for Kotlin API參考

基本概念

以下程式碼範例顯示做法:

  • 建立鍵空間和資料表。資料表結構描述會保留影片資料並 point-in-time已啟用復原。

  • 使用 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、擷取和更新影片資料。

  • 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 適用於 Kotlin
注意

還有更多 。 GitHub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 Kotlin 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-kotlin/latest/developer-guide/setup.html This example uses a secure file format to hold certificate information for Kotlin 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 Kotlin 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. */ /* 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. */ val DASHES: String = String(CharArray(80)).replace("\u0000", "-") suspend fun main() { val fileName = "<Replace with the JSON file that contains movie data>" val keyspaceName = "<Replace with the name of the keyspace to create>" val titleUpdate = "The Family" val yearUpdate = 2013 val tableName = "MovieKotlin" val tableNameRestore = "MovieRestore" val loader = DriverConfigLoader.fromClasspath("application.conf") val session = CqlSession .builder() .withConfigLoader(loader) .build() println(DASHES) println("Welcome to the Amazon Keyspaces example scenario.") println(DASHES) println(DASHES) println("1. Create a keyspace.") createKeySpace(keyspaceName) println(DASHES) println(DASHES) delay(5000) println("2. Check for keyspace existence.") checkKeyspaceExistence(keyspaceName) println(DASHES) println(DASHES) println("3. List keyspaces using a paginator.") listKeyspacesPaginator() println(DASHES) println(DASHES) println("4. Create a table with a simple movie data schema and enable point-in-time recovery.") createTable(keyspaceName, tableName) println(DASHES) println(DASHES) println("5. Check for the table to be in an Active state.") delay(6000) checkTable(keyspaceName, tableName) println(DASHES) println(DASHES) println("6. List all tables in the keyspace.") listTables(keyspaceName) println(DASHES) println(DASHES) println("7. Use a Cassandra driver to insert some records into the Movie table.") delay(6000) loadData(session, fileName, keyspaceName) println(DASHES) println(DASHES) println("8. Get all records from the Movie table.") getMovieData(session, keyspaceName) println(DASHES) println(DASHES) println("9. Get a specific Movie.") getSpecificMovie(session, keyspaceName) println(DASHES) println(DASHES) println("10. Get a UTC timestamp for the current time.") val utc = ZonedDateTime.now(ZoneOffset.UTC) println("DATETIME = ${Date.from(utc.toInstant())}") println(DASHES) println(DASHES) println("11. Update the table schema to add a watched Boolean column.") updateTable(keyspaceName, tableName) println(DASHES) println(DASHES) println("12. Update an item as watched.") delay(10000) // Wait 10 seconds for the update. updateRecord(session, keyspaceName, titleUpdate, yearUpdate) println(DASHES) println(DASHES) println("13. Query for items with watched = True.") getWatchedData(session, keyspaceName) println(DASHES) println(DASHES) println("14. Restore the table back to the previous state using the timestamp.") println("Note that the restore operation can take up to 20 minutes.") restoreTable(keyspaceName, utc) println(DASHES) println(DASHES) println("15. Check for completion of the restore action.") delay(5000) checkRestoredTable(keyspaceName, "MovieRestore") println(DASHES) println(DASHES) println("16. Delete both tables.") deleteTable(keyspaceName, tableName) deleteTable(keyspaceName, tableNameRestore) println(DASHES) println(DASHES) println("17. Confirm that both tables are deleted.") checkTableDelete(keyspaceName, tableName) checkTableDelete(keyspaceName, tableNameRestore) println(DASHES) println(DASHES) println("18. Delete the keyspace.") deleteKeyspace(keyspaceName) println(DASHES) println(DASHES) println("The scenario has completed successfully.") println(DASHES) } suspend fun deleteKeyspace(keyspaceNameVal: String?) { val deleteKeyspaceRequest = DeleteKeyspaceRequest { keyspaceName = keyspaceNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient.deleteKeyspace(deleteKeyspaceRequest) } } suspend fun checkTableDelete( keyspaceNameVal: String?, tableNameVal: String?, ) { var status: String var response: GetTableResponse val tableRequest = GetTableRequest { keyspaceName = keyspaceNameVal tableName = tableNameVal } try { KeyspacesClient { region = "us-east-1" }.use { keyClient -> // Keep looping until the table cannot be found and a ResourceNotFoundException is thrown. while (true) { response = keyClient.getTable(tableRequest) status = response.status.toString() println(". The table status is $status") delay(500) } } } catch (e: ResourceNotFoundException) { println(e.message) } println("The table is deleted") } suspend fun deleteTable( keyspaceNameVal: String?, tableNameVal: String?, ) { val tableRequest = DeleteTableRequest { keyspaceName = keyspaceNameVal tableName = tableNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient.deleteTable(tableRequest) } } suspend fun checkRestoredTable( keyspaceNameVal: String?, tableNameVal: String?, ) { var tableStatus = false var status: String var response: GetTableResponse? = null val tableRequest = GetTableRequest { keyspaceName = keyspaceNameVal tableName = tableNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> while (!tableStatus) { response = keyClient.getTable(tableRequest) status = response!!.status.toString() println("The table status is $status") if (status.compareTo("ACTIVE") == 0) { tableStatus = true } delay(500) } val cols = response!!.schemaDefinition?.allColumns if (cols != null) { for (def in cols) { println("The column name is ${def.name}") println("The column type is ${def.type}") } } } } suspend fun restoreTable( keyspaceName: String?, utc: ZonedDateTime, ) { // Create an aws.smithy.kotlin.runtime.time.Instant value. val timeStamp = aws.smithy.kotlin.runtime.time .Instant(utc.toInstant()) val restoreTableRequest = RestoreTableRequest { restoreTimestamp = timeStamp sourceTableName = "MovieKotlin" targetKeyspaceName = keyspaceName targetTableName = "MovieRestore" sourceKeyspaceName = keyspaceName } KeyspacesClient { region = "us-east-1" }.use { keyClient -> val response = keyClient.restoreTable(restoreTableRequest) println("The ARN of the restored table is ${response.restoredTableArn}") } } fun getWatchedData( session: CqlSession, keyspaceName: String, ) { val resultSet = session.execute("SELECT * FROM \"$keyspaceName\".\"MovieKotlin\" WHERE watched = true ALLOW FILTERING;") resultSet.forEach { item: Row -> println("The Movie title is ${item.getString("title")}") println("The Movie year is ${item.getInt("year")}") println("The plot is ${item.getString("plot")}") } } fun updateRecord( session: CqlSession, keySpace: String, titleUpdate: String?, yearUpdate: Int, ) { val sqlStatement = "UPDATE \"$keySpace\".\"MovieKotlin\" SET watched=true WHERE title = :k0 AND year = :k1;" val builder = BatchStatement.builder(DefaultBatchType.UNLOGGED) builder.setConsistencyLevel(ConsistencyLevel.LOCAL_QUORUM) val preparedStatement = session.prepare(sqlStatement) builder.addStatement( preparedStatement .boundStatementBuilder() .setString("k0", titleUpdate) .setInt("k1", yearUpdate) .build(), ) val batchStatement = builder.build() session.execute(batchStatement) } suspend fun updateTable( keySpace: String?, tableNameVal: String?, ) { val def = ColumnDefinition { name = "watched" type = "boolean" } val tableRequest = UpdateTableRequest { keyspaceName = keySpace tableName = tableNameVal addColumns = listOf(def) } KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient.updateTable(tableRequest) } } fun getSpecificMovie( session: CqlSession, keyspaceName: String, ) { val resultSet = session.execute("SELECT * FROM \"$keyspaceName\".\"MovieKotlin\" WHERE title = 'The Family' ALLOW FILTERING ;") resultSet.forEach { item: Row -> println("The Movie title is ${item.getString("title")}") println("The Movie year is ${item.getInt("year")}") println("The plot is ${item.getString("plot")}") } } // Get records from the Movie table. fun getMovieData( session: CqlSession, keyspaceName: String, ) { val resultSet = session.execute("SELECT * FROM \"$keyspaceName\".\"MovieKotlin\";") resultSet.forEach { item: Row -> println("The Movie title is ${item.getString("title")}") println("The Movie year is ${item.getInt("year")}") println("The plot is ${item.getString("plot")}") } } // Load data into the table. fun loadData( session: CqlSession, fileName: String, keySpace: String, ) { val sqlStatement = "INSERT INTO \"$keySpace\".\"MovieKotlin\" (title, year, plot) values (:k0, :k1, :k2)" val parser = JsonFactory().createParser(File(fileName)) val rootNode = ObjectMapper().readTree<JsonNode>(parser) val iter: Iterator<JsonNode> = rootNode.iterator() var currentNode: ObjectNode var t = 0 while (iter.hasNext()) { if (t == 50) { break } currentNode = iter.next() as ObjectNode val year = currentNode.path("year").asInt() val title = currentNode.path("title").asText() val info = currentNode.path("info").toString() // Insert the data into the Amazon Keyspaces table. val builder = BatchStatement.builder(DefaultBatchType.UNLOGGED) builder.setConsistencyLevel(ConsistencyLevel.LOCAL_QUORUM) val preparedStatement: PreparedStatement = session.prepare(sqlStatement) builder.addStatement( preparedStatement .boundStatementBuilder() .setString("k0", title) .setInt("k1", year) .setString("k2", info) .build(), ) val batchStatement = builder.build() session.execute(batchStatement) t++ } } suspend fun listTables(keyspaceNameVal: String?) { val tablesRequest = ListTablesRequest { keyspaceName = keyspaceNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient .listTablesPaginated(tablesRequest) .transform { it.tables?.forEach { obj -> emit(obj) } } .collect { obj -> println(" ARN: ${obj.resourceArn} Table name: ${obj.tableName}") } } } suspend fun checkTable( keyspaceNameVal: String?, tableNameVal: String?, ) { var tableStatus = false var status: String var response: GetTableResponse? = null val tableRequest = GetTableRequest { keyspaceName = keyspaceNameVal tableName = tableNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> while (!tableStatus) { response = keyClient.getTable(tableRequest) status = response!!.status.toString() println(". The table status is $status") if (status.compareTo("ACTIVE") == 0) { tableStatus = true } delay(500) } val cols: List<ColumnDefinition>? = response!!.schemaDefinition?.allColumns if (cols != null) { for (def in cols) { println("The column name is ${def.name}") println("The column type is ${def.type}") } } } } suspend fun createTable( keySpaceVal: String?, tableNameVal: String?, ) { // Set the columns. val defTitle = ColumnDefinition { name = "title" type = "text" } val defYear = ColumnDefinition { name = "year" type = "int" } val defReleaseDate = ColumnDefinition { name = "release_date" type = "timestamp" } val defPlot = ColumnDefinition { name = "plot" type = "text" } val colList = ArrayList<ColumnDefinition>() colList.add(defTitle) colList.add(defYear) colList.add(defReleaseDate) colList.add(defPlot) // Set the keys. val yearKey = PartitionKey { name = "year" } val titleKey = PartitionKey { name = "title" } val keyList = ArrayList<PartitionKey>() keyList.add(yearKey) keyList.add(titleKey) val schemaDefinitionOb = SchemaDefinition { partitionKeys = keyList allColumns = colList } val timeRecovery = PointInTimeRecovery { status = PointInTimeRecoveryStatus.Enabled } val tableRequest = CreateTableRequest { keyspaceName = keySpaceVal tableName = tableNameVal schemaDefinition = schemaDefinitionOb pointInTimeRecovery = timeRecovery } KeyspacesClient { region = "us-east-1" }.use { keyClient -> val response = keyClient.createTable(tableRequest) println("The table ARN is ${response.resourceArn}") } } suspend fun listKeyspacesPaginator() { KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient .listKeyspacesPaginated(ListKeyspacesRequest {}) .transform { it.keyspaces?.forEach { obj -> emit(obj) } } .collect { obj -> println("Name: ${obj.keyspaceName}") } } } suspend fun checkKeyspaceExistence(keyspaceNameVal: String?) { val keyspaceRequest = GetKeyspaceRequest { keyspaceName = keyspaceNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> val response: GetKeyspaceResponse = keyClient.getKeyspace(keyspaceRequest) val name = response.keyspaceName println("The $name KeySpace is ready") } } suspend fun createKeySpace(keyspaceNameVal: String) { val keyspaceRequest = CreateKeyspaceRequest { keyspaceName = keyspaceNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> val response = keyClient.createKeyspace(keyspaceRequest) println("The ARN of the KeySpace is ${response.resourceArn}") } }

動作

下列程式碼範例示範如何使用 CreateKeyspace

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun createKeySpace(keyspaceNameVal: String) { val keyspaceRequest = CreateKeyspaceRequest { keyspaceName = keyspaceNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> val response = keyClient.createKeyspace(keyspaceRequest) println("The ARN of the KeySpace is ${response.resourceArn}") } }
  • 如需API詳細資訊,請參閱CreateKeyspace中的 AWS SDK for Kotlin API參考

下列程式碼範例示範如何使用 CreateTable

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun createTable( keySpaceVal: String?, tableNameVal: String?, ) { // Set the columns. val defTitle = ColumnDefinition { name = "title" type = "text" } val defYear = ColumnDefinition { name = "year" type = "int" } val defReleaseDate = ColumnDefinition { name = "release_date" type = "timestamp" } val defPlot = ColumnDefinition { name = "plot" type = "text" } val colList = ArrayList<ColumnDefinition>() colList.add(defTitle) colList.add(defYear) colList.add(defReleaseDate) colList.add(defPlot) // Set the keys. val yearKey = PartitionKey { name = "year" } val titleKey = PartitionKey { name = "title" } val keyList = ArrayList<PartitionKey>() keyList.add(yearKey) keyList.add(titleKey) val schemaDefinitionOb = SchemaDefinition { partitionKeys = keyList allColumns = colList } val timeRecovery = PointInTimeRecovery { status = PointInTimeRecoveryStatus.Enabled } val tableRequest = CreateTableRequest { keyspaceName = keySpaceVal tableName = tableNameVal schemaDefinition = schemaDefinitionOb pointInTimeRecovery = timeRecovery } KeyspacesClient { region = "us-east-1" }.use { keyClient -> val response = keyClient.createTable(tableRequest) println("The table ARN is ${response.resourceArn}") } }
  • 如需API詳細資訊,請參閱CreateTable中的 AWS SDK for Kotlin API參考

下列程式碼範例示範如何使用 DeleteKeyspace

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun deleteKeyspace(keyspaceNameVal: String?) { val deleteKeyspaceRequest = DeleteKeyspaceRequest { keyspaceName = keyspaceNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient.deleteKeyspace(deleteKeyspaceRequest) } }
  • 如需API詳細資訊,請參閱DeleteKeyspace中的 AWS SDK for Kotlin API參考

下列程式碼範例示範如何使用 DeleteTable

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun deleteTable( keyspaceNameVal: String?, tableNameVal: String?, ) { val tableRequest = DeleteTableRequest { keyspaceName = keyspaceNameVal tableName = tableNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient.deleteTable(tableRequest) } }
  • 如需API詳細資訊,請參閱DeleteTable中的 AWS SDK for Kotlin API參考

下列程式碼範例示範如何使用 GetKeyspace

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun checkKeyspaceExistence(keyspaceNameVal: String?) { val keyspaceRequest = GetKeyspaceRequest { keyspaceName = keyspaceNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> val response: GetKeyspaceResponse = keyClient.getKeyspace(keyspaceRequest) val name = response.keyspaceName println("The $name KeySpace is ready") } }
  • 如需API詳細資訊,請參閱GetKeyspace中的 AWS SDK for Kotlin API參考

下列程式碼範例示範如何使用 GetTable

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun checkTable( keyspaceNameVal: String?, tableNameVal: String?, ) { var tableStatus = false var status: String var response: GetTableResponse? = null val tableRequest = GetTableRequest { keyspaceName = keyspaceNameVal tableName = tableNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> while (!tableStatus) { response = keyClient.getTable(tableRequest) status = response!!.status.toString() println(". The table status is $status") if (status.compareTo("ACTIVE") == 0) { tableStatus = true } delay(500) } val cols: List<ColumnDefinition>? = response!!.schemaDefinition?.allColumns if (cols != null) { for (def in cols) { println("The column name is ${def.name}") println("The column type is ${def.type}") } } } }
  • 如需API詳細資訊,請參閱GetTable中的 AWS SDK for Kotlin API參考

下列程式碼範例示範如何使用 ListKeyspaces

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun listKeyspacesPaginator() { KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient .listKeyspacesPaginated(ListKeyspacesRequest {}) .transform { it.keyspaces?.forEach { obj -> emit(obj) } } .collect { obj -> println("Name: ${obj.keyspaceName}") } } }
  • 如需API詳細資訊,請參閱ListKeyspaces中的 AWS SDK for Kotlin API參考

下列程式碼範例示範如何使用 ListTables

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun listTables(keyspaceNameVal: String?) { val tablesRequest = ListTablesRequest { keyspaceName = keyspaceNameVal } KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient .listTablesPaginated(tablesRequest) .transform { it.tables?.forEach { obj -> emit(obj) } } .collect { obj -> println(" ARN: ${obj.resourceArn} Table name: ${obj.tableName}") } } }
  • 如需API詳細資訊,請參閱ListTables中的 AWS SDK for Kotlin API參考

下列程式碼範例示範如何使用 RestoreTable

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun restoreTable( keyspaceName: String?, utc: ZonedDateTime, ) { // Create an aws.smithy.kotlin.runtime.time.Instant value. val timeStamp = aws.smithy.kotlin.runtime.time .Instant(utc.toInstant()) val restoreTableRequest = RestoreTableRequest { restoreTimestamp = timeStamp sourceTableName = "MovieKotlin" targetKeyspaceName = keyspaceName targetTableName = "MovieRestore" sourceKeyspaceName = keyspaceName } KeyspacesClient { region = "us-east-1" }.use { keyClient -> val response = keyClient.restoreTable(restoreTableRequest) println("The ARN of the restored table is ${response.restoredTableArn}") } }
  • 如需API詳細資訊,請參閱RestoreTable中的 AWS SDK for Kotlin API參考

下列程式碼範例示範如何使用 UpdateTable

SDK 適用於 Kotlin
注意

還有更多 。 GitHub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。

suspend fun updateTable( keySpace: String?, tableNameVal: String?, ) { val def = ColumnDefinition { name = "watched" type = "boolean" } val tableRequest = UpdateTableRequest { keyspaceName = keySpace tableName = tableNameVal addColumns = listOf(def) } KeyspacesClient { region = "us-east-1" }.use { keyClient -> keyClient.updateTable(tableRequest) } }
  • 如需API詳細資訊,請參閱UpdateTable中的 AWS SDK for Kotlin API參考