代码示例 - Amazon Athena
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代码示例

使用本主题中的示例作为使用适用于 Java 2.x 的软件开发工具包编写 Athena 应用程序的起始点。有关运行 Java 代码示例的更多信息,请参阅 Amazon 代码示例存储库上的 Amazon Athena Java 自述文件(位于 GitHub 上)。

注意

这些示例对字符串使用常量(例如,ATHENA_SAMPLE_QUERY),它们是在 ExampleConstants.java 类声明中定义的。使用您自己的字符串或定义常量来替换这些常量。

常量

ExampleConstants.java 类演示了如何在 Athena 中查询由开始使用教程创建的表。

package aws.example.athena; public class ExampleConstants { public static final int CLIENT_EXECUTION_TIMEOUT = 100000; public static final String ATHENA_OUTPUT_BUCKET = "s3://bucketscott2"; // change the Amazon S3 bucket name to match your environment // Demonstrates how to query a table with a comma-separated value (CSV) table. For information, see //https://docs.aws.amazon.com/athena/latest/ug/work-with-data.html public static final String ATHENA_SAMPLE_QUERY = "SELECT * FROM scott2;"; // change the Query statement to match your environment public static final long SLEEP_AMOUNT_IN_MS = 1000; public static final String ATHENA_DEFAULT_DATABASE = "mydatabase"; // change the database to match your database }

创建客户端以访问 Athena

AthenaClientFactory.java 类显示如何创建和配置 Amazon Athena 客户端。

package aws.example.athena; import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.athena.AthenaClient; import software.amazon.awssdk.services.athena.AthenaClientBuilder; public class AthenaClientFactory { private final AthenaClientBuilder builder = AthenaClient.builder() .region(Region.US_WEST_2) .credentialsProvider(ProfileCredentialsProvider.create()); public AthenaClient createClient() { return builder.build(); } }

开始查询执行

StartQueryExample 显示如何向 Athena 提交查询以供执行,等待结果可用,然后处理结果。

package aws.example.athena; import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.athena.AthenaClient; import software.amazon.awssdk.services.athena.model.QueryExecutionContext; import software.amazon.awssdk.services.athena.model.ResultConfiguration; import software.amazon.awssdk.services.athena.model.StartQueryExecutionRequest; import software.amazon.awssdk.services.athena.model.StartQueryExecutionResponse; import software.amazon.awssdk.services.athena.model.AthenaException; import software.amazon.awssdk.services.athena.model.GetQueryExecutionRequest; import software.amazon.awssdk.services.athena.model.GetQueryExecutionResponse; import software.amazon.awssdk.services.athena.model.QueryExecutionState; import software.amazon.awssdk.services.athena.model.GetQueryResultsRequest; import software.amazon.awssdk.services.athena.model.GetQueryResultsResponse; import software.amazon.awssdk.services.athena.model.ColumnInfo; import software.amazon.awssdk.services.athena.model.Row; import software.amazon.awssdk.services.athena.model.Datum; import software.amazon.awssdk.services.athena.paginators.GetQueryResultsIterable; 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 StartQueryExample { public static void main(String[] args) throws InterruptedException { AthenaClient athenaClient = AthenaClient.builder() .region(Region.US_WEST_2) .credentialsProvider(ProfileCredentialsProvider.create()) .build(); String queryExecutionId = submitAthenaQuery(athenaClient); waitForQueryToComplete(athenaClient, queryExecutionId); processResultRows(athenaClient, queryExecutionId); athenaClient.close(); } // Submits a sample query to Amazon Athena and returns the execution ID of the query. public static String submitAthenaQuery(AthenaClient athenaClient) { try { // The QueryExecutionContext allows us to set the database. QueryExecutionContext queryExecutionContext = QueryExecutionContext.builder() .database(ExampleConstants.ATHENA_DEFAULT_DATABASE) .build(); // The result configuration specifies where the results of the query should go. ResultConfiguration resultConfiguration = ResultConfiguration.builder() .outputLocation(ExampleConstants.ATHENA_OUTPUT_BUCKET) .build(); StartQueryExecutionRequest startQueryExecutionRequest = StartQueryExecutionRequest.builder() .queryString(ExampleConstants.ATHENA_SAMPLE_QUERY) .queryExecutionContext(queryExecutionContext) .resultConfiguration(resultConfiguration) .build(); StartQueryExecutionResponse startQueryExecutionResponse = athenaClient.startQueryExecution(startQueryExecutionRequest); return startQueryExecutionResponse.queryExecutionId(); } catch (AthenaException e) { e.printStackTrace(); System.exit(1); } return ""; } // Wait for an Amazon Athena query to complete, fail or to be cancelled. public static void waitForQueryToComplete(AthenaClient athenaClient, String queryExecutionId) throws InterruptedException { GetQueryExecutionRequest getQueryExecutionRequest = GetQueryExecutionRequest.builder() .queryExecutionId(queryExecutionId) .build(); GetQueryExecutionResponse getQueryExecutionResponse; boolean isQueryStillRunning = true; while (isQueryStillRunning) { getQueryExecutionResponse = athenaClient.getQueryExecution(getQueryExecutionRequest); String queryState = getQueryExecutionResponse.queryExecution().status().state().toString(); if (queryState.equals(QueryExecutionState.FAILED.toString())) { throw new RuntimeException("The Amazon Athena query failed to run with error message: " + getQueryExecutionResponse .queryExecution().status().stateChangeReason()); } else if (queryState.equals(QueryExecutionState.CANCELLED.toString())) { throw new RuntimeException("The Amazon Athena query was cancelled."); } else if (queryState.equals(QueryExecutionState.SUCCEEDED.toString())) { isQueryStillRunning = false; } else { // Sleep an amount of time before retrying again. Thread.sleep(ExampleConstants.SLEEP_AMOUNT_IN_MS); } System.out.println("The current status is: " + queryState); } } // This code retrieves the results of a query public static void processResultRows(AthenaClient athenaClient, String queryExecutionId) { try { // Max Results can be set but if its not set, // it will choose the maximum page size. GetQueryResultsRequest getQueryResultsRequest = GetQueryResultsRequest.builder() .queryExecutionId(queryExecutionId) .build(); GetQueryResultsIterable getQueryResultsResults = athenaClient.getQueryResultsPaginator(getQueryResultsRequest); for (GetQueryResultsResponse result : getQueryResultsResults) { List<ColumnInfo> columnInfoList = result.resultSet().resultSetMetadata().columnInfo(); List<Row> results = result.resultSet().rows(); processRow(results, columnInfoList); } } catch (AthenaException e) { e.printStackTrace(); System.exit(1); } } private static void processRow(List<Row> row, List<ColumnInfo> columnInfoList) { for (Row myRow : row) { List<Datum> allData = myRow.data(); for (Datum data : allData) { System.out.println("The value of the column is "+data.varCharValue()); } } } }

停止查询执行

StopQueryExecutionExample 运行示例查询,立即停止查询,并检查查询的状态以确保它已被取消。

package aws.example.athena; import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.athena.AthenaClient; import software.amazon.awssdk.services.athena.model.StopQueryExecutionRequest; import software.amazon.awssdk.services.athena.model.GetQueryExecutionRequest; import software.amazon.awssdk.services.athena.model.GetQueryExecutionResponse; import software.amazon.awssdk.services.athena.model.QueryExecutionState; import software.amazon.awssdk.services.athena.model.AthenaException; import software.amazon.awssdk.services.athena.model.QueryExecutionContext; import software.amazon.awssdk.services.athena.model.ResultConfiguration; import software.amazon.awssdk.services.athena.model.StartQueryExecutionRequest; import software.amazon.awssdk.services.athena.model.StartQueryExecutionResponse; /** * 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 StopQueryExecutionExample { public static void main(String[] args) { AthenaClient athenaClient = AthenaClient.builder() .region(Region.US_WEST_2) .credentialsProvider(ProfileCredentialsProvider.create()) .build(); String sampleQueryExecutionId = submitAthenaQuery(athenaClient); stopAthenaQuery(athenaClient, sampleQueryExecutionId); athenaClient.close(); } public static void stopAthenaQuery(AthenaClient athenaClient, String sampleQueryExecutionId){ try { StopQueryExecutionRequest stopQueryExecutionRequest = StopQueryExecutionRequest.builder() .queryExecutionId(sampleQueryExecutionId) .build(); athenaClient.stopQueryExecution(stopQueryExecutionRequest); // Ensure that the query was stopped. GetQueryExecutionRequest getQueryExecutionRequest = GetQueryExecutionRequest.builder() .queryExecutionId(sampleQueryExecutionId) .build(); GetQueryExecutionResponse getQueryExecutionResponse = athenaClient.getQueryExecution(getQueryExecutionRequest); if (getQueryExecutionResponse.queryExecution() .status() .state() .equals(QueryExecutionState.CANCELLED)) { System.out.println("The Amazon Athena query has been cancelled!"); } } catch (AthenaException e) { e.printStackTrace(); System.exit(1); } } // Submits an example query and returns a query execution Id value public static String submitAthenaQuery(AthenaClient athenaClient) { try { QueryExecutionContext queryExecutionContext = QueryExecutionContext.builder() .database(ExampleConstants.ATHENA_DEFAULT_DATABASE) .build(); ResultConfiguration resultConfiguration = ResultConfiguration.builder() .outputLocation(ExampleConstants.ATHENA_OUTPUT_BUCKET) .build(); StartQueryExecutionRequest startQueryExecutionRequest = StartQueryExecutionRequest.builder() .queryExecutionContext(queryExecutionContext) .queryString(ExampleConstants.ATHENA_SAMPLE_QUERY) .resultConfiguration(resultConfiguration).build(); StartQueryExecutionResponse startQueryExecutionResponse = athenaClient.startQueryExecution(startQueryExecutionRequest); return startQueryExecutionResponse.queryExecutionId(); } catch (AthenaException e) { e.printStackTrace(); System.exit(1); } return null; } }

列出查询执行

ListQueryExecutionsExample 显示如何获取查询执行 ID 的列表。

package aws.example.athena; import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.athena.AthenaClient; import software.amazon.awssdk.services.athena.model.AthenaException; import software.amazon.awssdk.services.athena.model.ListQueryExecutionsRequest; import software.amazon.awssdk.services.athena.model.ListQueryExecutionsResponse; import software.amazon.awssdk.services.athena.paginators.ListQueryExecutionsIterable; 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 ListQueryExecutionsExample { public static void main(String[] args) { AthenaClient athenaClient = AthenaClient.builder() .region(Region.US_WEST_2) .credentialsProvider(ProfileCredentialsProvider.create()) .build(); listQueryIds(athenaClient); athenaClient.close(); } public static void listQueryIds(AthenaClient athenaClient) { try { ListQueryExecutionsRequest listQueryExecutionsRequest = ListQueryExecutionsRequest.builder().build(); ListQueryExecutionsIterable listQueryExecutionResponses = athenaClient.listQueryExecutionsPaginator(listQueryExecutionsRequest); for (ListQueryExecutionsResponse listQueryExecutionResponse : listQueryExecutionResponses) { List<String> queryExecutionIds = listQueryExecutionResponse.queryExecutionIds(); System.out.println("\n" +queryExecutionIds); } } catch (AthenaException e) { e.printStackTrace(); System.exit(1); } } }

创建命名查询

CreateNamedQueryExample 显示如何创建命名查询。

package aws.example.athena; import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.athena.AthenaClient; import software.amazon.awssdk.services.athena.model.AthenaException; import software.amazon.awssdk.services.athena.model.CreateNamedQueryRequest; /** * 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 CreateNamedQueryExample { public static void main(String[] args) { final String USAGE = "\n" + "Usage:\n" + " <name>\n\n" + "Where:\n" + " name - the name of the Amazon Athena query. \n\n" ; if (args.length != 1) { System.out.println(USAGE); System.exit(1); } String name = args[0]; AthenaClient athenaClient = AthenaClient.builder() .region(Region.US_WEST_2) .credentialsProvider(ProfileCredentialsProvider.create()) .build(); createNamedQuery(athenaClient, name); athenaClient.close(); } public static void createNamedQuery(AthenaClient athenaClient, String name) { try { // Create the named query request. CreateNamedQueryRequest createNamedQueryRequest = CreateNamedQueryRequest.builder() .database(ExampleConstants.ATHENA_DEFAULT_DATABASE) .queryString(ExampleConstants.ATHENA_SAMPLE_QUERY) .description("Sample Description") .name(name) .build(); athenaClient.createNamedQuery(createNamedQueryRequest); System.out.println("Done"); } catch (AthenaException e) { e.printStackTrace(); System.exit(1); } } }

删除命名查询

DeleteNamedQueryExample 显示如何使用命名查询 ID 删除命名查询。

package aws.example.athena; import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.athena.AthenaClient; import software.amazon.awssdk.services.athena.model.DeleteNamedQueryRequest; import software.amazon.awssdk.services.athena.model.AthenaException; import software.amazon.awssdk.services.athena.model.CreateNamedQueryRequest; import software.amazon.awssdk.services.athena.model.CreateNamedQueryResponse; /** * 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 DeleteNamedQueryExample { public static void main(String[] args) { final String USAGE = "\n" + "Usage:\n" + " <name>\n\n" + "Where:\n" + " name - the name of the Amazon Athena query. \n\n" ; if (args.length != 1) { System.out.println(USAGE); System.exit(1); } String name = args[0]; AthenaClient athenaClient = AthenaClient.builder() .region(Region.US_WEST_2) .credentialsProvider(ProfileCredentialsProvider.create()) .build(); String sampleNamedQueryId = getNamedQueryId(athenaClient, name); deleteQueryName(athenaClient, sampleNamedQueryId); athenaClient.close(); } public static void deleteQueryName(AthenaClient athenaClient, String sampleNamedQueryId) { try { DeleteNamedQueryRequest deleteNamedQueryRequest = DeleteNamedQueryRequest.builder() .namedQueryId(sampleNamedQueryId) .build(); athenaClient.deleteNamedQuery(deleteNamedQueryRequest); } catch (AthenaException e) { e.printStackTrace(); System.exit(1); } } public static String getNamedQueryId(AthenaClient athenaClient, String name) { try { CreateNamedQueryRequest createNamedQueryRequest = CreateNamedQueryRequest.builder() .database(ExampleConstants.ATHENA_DEFAULT_DATABASE) .queryString(ExampleConstants.ATHENA_SAMPLE_QUERY) .name(name) .description("Sample description") .build(); CreateNamedQueryResponse createNamedQueryResponse = athenaClient.createNamedQuery(createNamedQueryRequest); return createNamedQueryResponse.namedQueryId(); } catch (AthenaException e) { e.printStackTrace(); System.exit(1); } return null; } }

列出命名查询

ListNamedQueryExample 显示如何获取命名查询 ID 的列表。

package aws.example.athena; import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.athena.AthenaClient; import software.amazon.awssdk.services.athena.model.AthenaException; import software.amazon.awssdk.services.athena.model.ListNamedQueriesRequest; import software.amazon.awssdk.services.athena.model.ListNamedQueriesResponse; import software.amazon.awssdk.services.athena.paginators.ListNamedQueriesIterable; 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 ListNamedQueryExample { public static void main(String[] args) { AthenaClient athenaClient = AthenaClient.builder() .region(Region.US_WEST_2) .credentialsProvider(ProfileCredentialsProvider.create()) .build(); listNamedQueries(athenaClient) ; athenaClient.close(); } public static void listNamedQueries(AthenaClient athenaClient) { try{ ListNamedQueriesRequest listNamedQueriesRequest = ListNamedQueriesRequest.builder() .build(); ListNamedQueriesIterable listNamedQueriesResponses = athenaClient.listNamedQueriesPaginator(listNamedQueriesRequest); for (ListNamedQueriesResponse listNamedQueriesResponse : listNamedQueriesResponses) { List<String> namedQueryIds = listNamedQueriesResponse.namedQueryIds(); System.out.println(namedQueryIds); } } catch (AthenaException e) { e.printStackTrace(); System.exit(1); } } }