Beispiele für die Verwendung von Amazon Keyspaces SDK für Kotlin

/**
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}")
        }
    }
}

/**
 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}")
    }
}

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}")
    }
}

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 deleteKeyspace(keyspaceNameVal: String?) {
    val deleteKeyspaceRequest =
        DeleteKeyspaceRequest {
            keyspaceName = keyspaceNameVal
        }

    KeyspacesClient { region = "us-east-1" }.use { keyClient ->
        keyClient.deleteKeyspace(deleteKeyspaceRequest)
    }
}

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 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 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 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 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 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}")
    }
}

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)
    }
}