SDK for Java 2.x を使用した Lambda の例

次のコード例は、Lambda AWS SDK for Java 2.x でを使用してアクションを実行し、一般的なシナリオを実装する方法を示しています。

アクションはより大きなプログラムからのコードの抜粋であり、コンテキスト内で実行する必要があります。アクションは個々のサービス機能を呼び出す方法を示していますが、関連するシナリオやサービス間の例ではアクションのコンテキストが確認できます。

「シナリオ」は、同じサービス内で複数の関数を呼び出して、特定のタスクを実行する方法を示すコード例です。

各例には、へのリンクが含まれています。ここでは GitHub、コンテキスト内でコードを設定および実行する方法の手順を確認できます。

開始方法

次のコード例では、Lambda の使用を開始する方法について示しています。

SDK for Java 2.x

注記

については、「」を参照してください GitHub。AWS コード例リポジトリで全く同じ例を見つけて、設定と実行の方法を確認してください。


package com.example.lambda;

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.lambda.LambdaClient;
import software.amazon.awssdk.services.lambda.model.LambdaException;
import software.amazon.awssdk.services.lambda.model.ListFunctionsResponse;
import software.amazon.awssdk.services.lambda.model.FunctionConfiguration;
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 ListLambdaFunctions {
    public static void main(String[] args) {
        Region region = Region.US_WEST_2;
        LambdaClient awsLambda = LambdaClient.builder()
                .region(region)
                .build();

        listFunctions(awsLambda);
        awsLambda.close();
    }

    public static void listFunctions(LambdaClient awsLambda) {
        try {
            ListFunctionsResponse functionResult = awsLambda.listFunctions();
            List<FunctionConfiguration> list = functionResult.functions();
            for (FunctionConfiguration config : list) {
                System.out.println("The function name is " + config.functionName());
            }

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
}

API 詳細については、「リファレンスListFunctions」の「」を参照してください。 AWS SDK for Java 2.x API

アクション

次の例は、CreateFunction を使用する方法を説明しています。

SDK for Java 2.x

注記

については、「」を参照してください GitHub。AWS コード例リポジトリで全く同じ例を見つけて、設定と実行の方法を確認してください。


import software.amazon.awssdk.core.SdkBytes;
import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.lambda.LambdaClient;
import software.amazon.awssdk.services.lambda.model.CreateFunctionRequest;
import software.amazon.awssdk.services.lambda.model.FunctionCode;
import software.amazon.awssdk.services.lambda.model.CreateFunctionResponse;
import software.amazon.awssdk.services.lambda.model.GetFunctionRequest;
import software.amazon.awssdk.services.lambda.model.GetFunctionResponse;
import software.amazon.awssdk.services.lambda.model.LambdaException;
import software.amazon.awssdk.services.lambda.model.Runtime;
import software.amazon.awssdk.services.lambda.waiters.LambdaWaiter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

/**
 * This code example requires a ZIP or JAR that represents the code of the
 * Lambda function.
 * If you do not have a ZIP or JAR, please refer to the following document:
 *
 * https://github.com/aws-doc-sdk-examples/tree/master/javav2/usecases/creating_workflows_stepfunctions
 *
 * Also, set up your development environment, including your credentials.
 *
 * For information, see this documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */

public class CreateFunction {
    public static void main(String[] args) {

        final String usage = """

                Usage:
                    <functionName> <filePath> <role> <handler>\s

                Where:
                    functionName - The name of the Lambda function.\s
                    filePath - The path to the ZIP or JAR where the code is located.\s
                    role - The role ARN that has Lambda permissions.\s
                    handler - The fully qualified method name (for example, example.Handler::handleRequest). \s
                """;

        if (args.length != 4) {
            System.out.println(usage);
            System.exit(1);
        }

        String functionName = args[0];
        String filePath = args[1];
        String role = args[2];
        String handler = args[3];
        Region region = Region.US_WEST_2;
        LambdaClient awsLambda = LambdaClient.builder()
                .region(region)
                .build();

        createLambdaFunction(awsLambda, functionName, filePath, role, handler);
        awsLambda.close();
    }

    public static void createLambdaFunction(LambdaClient awsLambda,
            String functionName,
            String filePath,
            String role,
            String handler) {

        try {
            LambdaWaiter waiter = awsLambda.waiter();
            InputStream is = new FileInputStream(filePath);
            SdkBytes fileToUpload = SdkBytes.fromInputStream(is);

            FunctionCode code = FunctionCode.builder()
                    .zipFile(fileToUpload)
                    .build();

            CreateFunctionRequest functionRequest = CreateFunctionRequest.builder()
                    .functionName(functionName)
                    .description("Created by the Lambda Java API")
                    .code(code)
                    .handler(handler)
                    .runtime(Runtime.JAVA8)
                    .role(role)
                    .build();

            // Create a Lambda function using a waiter.
            CreateFunctionResponse functionResponse = awsLambda.createFunction(functionRequest);
            GetFunctionRequest getFunctionRequest = GetFunctionRequest.builder()
                    .functionName(functionName)
                    .build();
            WaiterResponse<GetFunctionResponse> waiterResponse = waiter.waitUntilFunctionExists(getFunctionRequest);
            waiterResponse.matched().response().ifPresent(System.out::println);
            System.out.println("The function ARN is " + functionResponse.functionArn());

        } catch (LambdaException | FileNotFoundException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
}

API 詳細については、「リファレンスCreateFunction」の「」を参照してください。 AWS SDK for Java 2.x API

次の例は、DeleteFunction を使用する方法を説明しています。

SDK for Java 2.x

注記

については、「」を参照してください GitHub。AWS コード例リポジトリで全く同じ例を見つけて、設定と実行の方法を確認してください。


import software.amazon.awssdk.services.lambda.LambdaClient;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.lambda.model.DeleteFunctionRequest;
import software.amazon.awssdk.services.lambda.model.LambdaException;

/**
 * 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 DeleteFunction {
    public static void main(String[] args) {
        final String usage = """

                Usage:
                    <functionName>\s

                Where:
                    functionName - The name of the Lambda function.\s
                """;

        if (args.length != 1) {
            System.out.println(usage);
            System.exit(1);
        }

        String functionName = args[0];
        Region region = Region.US_EAST_1;
        LambdaClient awsLambda = LambdaClient.builder()
                .region(region)
                .build();

        deleteLambdaFunction(awsLambda, functionName);
        awsLambda.close();
    }

    public static void deleteLambdaFunction(LambdaClient awsLambda, String functionName) {
        try {
            DeleteFunctionRequest request = DeleteFunctionRequest.builder()
                    .functionName(functionName)
                    .build();

            awsLambda.deleteFunction(request);
            System.out.println("The " + functionName + " function was deleted");

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
}

API 詳細については、「リファレンスDeleteFunction」の「」を参照してください。 AWS SDK for Java 2.x API

次の例は、Invoke を使用する方法を説明しています。

SDK for Java 2.x

注記

については、「」を参照してください GitHub。AWS コード例リポジトリで全く同じ例を見つけて、設定と実行の方法を確認してください。


import org.json.JSONObject;
import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.services.lambda.LambdaClient;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.lambda.model.InvokeRequest;
import software.amazon.awssdk.core.SdkBytes;
import software.amazon.awssdk.services.lambda.model.InvokeResponse;
import software.amazon.awssdk.services.lambda.model.LambdaException;

public class LambdaInvoke {

    /*
     * Function names appear as
     * arn:aws:lambda:us-west-2:335556666777:function:HelloFunction
     * you can retrieve the value by looking at the function in the AWS Console
     *
     * Also, set up your development environment, including your credentials.
     *
     * For information, see this documentation topic:
     *
     * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.
     * html
     */

    public static void main(String[] args) {
        final String usage = """

                Usage:
                    <functionName>\s

                Where:
                    functionName - The name of the Lambda function\s
                """;

        if (args.length != 1) {
            System.out.println(usage);
            System.exit(1);
        }

        String functionName = args[0];
        Region region = Region.US_WEST_2;
        LambdaClient awsLambda = LambdaClient.builder()
                .region(region)
                .build();

        invokeFunction(awsLambda, functionName);
        awsLambda.close();
    }

    public static void invokeFunction(LambdaClient awsLambda, String functionName) {

        InvokeResponse res = null;
        try {
            // Need a SdkBytes instance for the payload.
            JSONObject jsonObj = new JSONObject();
            jsonObj.put("inputValue", "2000");
            String json = jsonObj.toString();
            SdkBytes payload = SdkBytes.fromUtf8String(json);

            // Setup an InvokeRequest.
            InvokeRequest request = InvokeRequest.builder()
                    .functionName(functionName)
                    .payload(payload)
                    .build();

            res = awsLambda.invoke(request);
            String value = res.payload().asUtf8String();
            System.out.println(value);

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
}

API 詳細については、「 AWS SDK for Java 2.x APIリファレンス」の「呼び出し」を参照してください。

シナリオ

次のコードサンプルは、以下の操作方法を示しています。

IAM ロールと Lambda 関数を作成し、ハンドラーコードをアップロードします。
1 つのパラメーターで関数を呼び出して、結果を取得します。
関数コードを更新し、環境変数で設定します。
新しいパラメーターで関数を呼び出して、結果を取得します。返された実行ログを表示します。
アカウントの関数を一覧表示し、リソースをクリーンアップします。

詳細については、「コンソールで Lambda 関数を作成する」を参照してください。

SDK for Java 2.x

注記

については、「」を参照してください GitHub。AWS コード例リポジトリで全く同じ例を見つけて、設定と実行の方法を確認してください。


/*
 *  Lambda function names appear as:
 *
 *  arn:aws:lambda:us-west-2:335556666777:function:HelloFunction
 *
 *  To find this value, look at the function in the AWS Management Console.
 *
 *  Before running this Java code example, set up your development environment, including your credentials.
 *
 *  For more information, see this documentation topic:
 *
 *  https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 *
 *  This example performs the following tasks:
 *
 * 1. Creates an AWS Lambda function.
 * 2. Gets a specific AWS Lambda function.
 * 3. Lists all Lambda functions.
 * 4. Invokes a Lambda function.
 * 5. Updates the Lambda function code and invokes it again.
 * 6. Updates a Lambda function's configuration value.
 * 7. Deletes a Lambda function.
 */

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

    public static void main(String[] args) throws InterruptedException {
        final String usage = """

                Usage:
                    <functionName> <filePath> <role> <handler> <bucketName> <key>\s

                Where:
                    functionName - The name of the Lambda function.\s
                    filePath - The path to the .zip or .jar where the code is located.\s
                    role - The AWS Identity and Access Management (IAM) service role that has Lambda permissions.\s
                    handler - The fully qualified method name (for example, example.Handler::handleRequest).\s
                    bucketName - The Amazon Simple Storage Service (Amazon S3) bucket name that contains the .zip or .jar used to update the Lambda function's code.\s
                    key - The Amazon S3 key name that represents the .zip or .jar (for example, LambdaHello-1.0-SNAPSHOT.jar).
                    """;

        if (args.length != 6) {
            System.out.println(usage);
            System.exit(1);
        }

        String functionName = args[0];
        String filePath = args[1];
        String role = args[2];
        String handler = args[3];
        String bucketName = args[4];
        String key = args[5];

        Region region = Region.US_WEST_2;
        LambdaClient awsLambda = LambdaClient.builder()
                .region(region)
                .build();

        System.out.println(DASHES);
        System.out.println("Welcome to the AWS Lambda example scenario.");
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("1. Create an AWS Lambda function.");
        String funArn = createLambdaFunction(awsLambda, functionName, filePath, role, handler);
        System.out.println("The AWS Lambda ARN is " + funArn);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("2. Get the " + functionName + " AWS Lambda function.");
        getFunction(awsLambda, functionName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("3. List all AWS Lambda functions.");
        listFunctions(awsLambda);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("4. Invoke the Lambda function.");
        System.out.println("*** Sleep for 1 min to get Lambda function ready.");
        Thread.sleep(60000);
        invokeFunction(awsLambda, functionName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("5. Update the Lambda function code and invoke it again.");
        updateFunctionCode(awsLambda, functionName, bucketName, key);
        System.out.println("*** Sleep for 1 min to get Lambda function ready.");
        Thread.sleep(60000);
        invokeFunction(awsLambda, functionName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("6. Update a Lambda function's configuration value.");
        updateFunctionConfiguration(awsLambda, functionName, handler);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("7. Delete the AWS Lambda function.");
        LambdaScenario.deleteLambdaFunction(awsLambda, functionName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("The AWS Lambda scenario completed successfully");
        System.out.println(DASHES);
        awsLambda.close();
    }

    public static String createLambdaFunction(LambdaClient awsLambda,
            String functionName,
            String filePath,
            String role,
            String handler) {

        try {
            LambdaWaiter waiter = awsLambda.waiter();
            InputStream is = new FileInputStream(filePath);
            SdkBytes fileToUpload = SdkBytes.fromInputStream(is);

            FunctionCode code = FunctionCode.builder()
                    .zipFile(fileToUpload)
                    .build();

            CreateFunctionRequest functionRequest = CreateFunctionRequest.builder()
                    .functionName(functionName)
                    .description("Created by the Lambda Java API")
                    .code(code)
                    .handler(handler)
                    .runtime(Runtime.JAVA8)
                    .role(role)
                    .build();

            // Create a Lambda function using a waiter
            CreateFunctionResponse functionResponse = awsLambda.createFunction(functionRequest);
            GetFunctionRequest getFunctionRequest = GetFunctionRequest.builder()
                    .functionName(functionName)
                    .build();
            WaiterResponse<GetFunctionResponse> waiterResponse = waiter.waitUntilFunctionExists(getFunctionRequest);
            waiterResponse.matched().response().ifPresent(System.out::println);
            return functionResponse.functionArn();

        } catch (LambdaException | FileNotFoundException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
        return "";
    }

    public static void getFunction(LambdaClient awsLambda, String functionName) {
        try {
            GetFunctionRequest functionRequest = GetFunctionRequest.builder()
                    .functionName(functionName)
                    .build();

            GetFunctionResponse response = awsLambda.getFunction(functionRequest);
            System.out.println("The runtime of this Lambda function is " + response.configuration().runtime());

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    public static void listFunctions(LambdaClient awsLambda) {
        try {
            ListFunctionsResponse functionResult = awsLambda.listFunctions();
            List<FunctionConfiguration> list = functionResult.functions();
            for (FunctionConfiguration config : list) {
                System.out.println("The function name is " + config.functionName());
            }

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    public static void invokeFunction(LambdaClient awsLambda, String functionName) {

        InvokeResponse res;
        try {
            // Need a SdkBytes instance for the payload.
            JSONObject jsonObj = new JSONObject();
            jsonObj.put("inputValue", "2000");
            String json = jsonObj.toString();
            SdkBytes payload = SdkBytes.fromUtf8String(json);

            InvokeRequest request = InvokeRequest.builder()
                    .functionName(functionName)
                    .payload(payload)
                    .build();

            res = awsLambda.invoke(request);
            String value = res.payload().asUtf8String();
            System.out.println(value);

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    public static void updateFunctionCode(LambdaClient awsLambda, String functionName, String bucketName, String key) {
        try {
            LambdaWaiter waiter = awsLambda.waiter();
            UpdateFunctionCodeRequest functionCodeRequest = UpdateFunctionCodeRequest.builder()
                    .functionName(functionName)
                    .publish(true)
                    .s3Bucket(bucketName)
                    .s3Key(key)
                    .build();

            UpdateFunctionCodeResponse response = awsLambda.updateFunctionCode(functionCodeRequest);
            GetFunctionConfigurationRequest getFunctionConfigRequest = GetFunctionConfigurationRequest.builder()
                    .functionName(functionName)
                    .build();

            WaiterResponse<GetFunctionConfigurationResponse> waiterResponse = waiter
                    .waitUntilFunctionUpdated(getFunctionConfigRequest);
            waiterResponse.matched().response().ifPresent(System.out::println);
            System.out.println("The last modified value is " + response.lastModified());

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    public static void updateFunctionConfiguration(LambdaClient awsLambda, String functionName, String handler) {
        try {
            UpdateFunctionConfigurationRequest configurationRequest = UpdateFunctionConfigurationRequest.builder()
                    .functionName(functionName)
                    .handler(handler)
                    .runtime(Runtime.JAVA11)
                    .build();

            awsLambda.updateFunctionConfiguration(configurationRequest);

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    public static void deleteLambdaFunction(LambdaClient awsLambda, String functionName) {
        try {
            DeleteFunctionRequest request = DeleteFunctionRequest.builder()
                    .functionName(functionName)
                    .build();

            awsLambda.deleteFunction(request);
            System.out.println("The " + functionName + " function was deleted");

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
}

API 詳細については、「 AWS SDK for Java 2.x APIリファレンス」の以下のトピックを参照してください。