で実行インターセプターを使用する AWS SDK for Java 2.x

AWS SDK for Java 2.x フック内の実行インターセプターをリクエストとレスポンスのライフサイクルに取り込み、API コール実行のさまざまな段階でカスタムロジックを実行します。インターセプターを使用して、ログ記録、メトリクス収集、リクエストの変更、デバッグ、エラー処理などのクロスカットの懸念を実装します。

インターセプターは、リクエスト実行のさまざまなフェーズにフックを提供する ExecutionInterceptorインターフェイスを実装します。

インターセプターのライフサイクル

ExecutionInterceptor インターフェイスには、リクエストの実行中に特定の時点で呼び出されるメソッドが用意されています。

インターセプターを登録する

overrideConfiguration メソッドを使用してサービスクライアントを構築するときに、インターセプターを登録します。複数のインターセプターを登録でき、登録順に実行されます。

// Register a single interceptor.
SqsClient client = SqsClient.builder()
    .overrideConfiguration(c -> c.addExecutionInterceptor(new LoggingInterceptor()))
    .build();

// Register multiple interceptors.
S3Client s3Client = S3Client.builder()
    .overrideConfiguration(config -> config
        .addExecutionInterceptor(new TimingInterceptor())
        .addExecutionInterceptor(new LoggingInterceptor())
        .addExecutionInterceptor(new RequestModificationInterceptor()))
    .build();

インターセプターの例

次のクラスでは、実行インターセプターを使用して、コアビジネスロジックを変更せずに、ログ記録、パフォーマンスモニタリング、リクエスト変更などのクロスカットの懸念を S3 オペレーションに追加する方法を示します。

この例では、S3 クライアントに複数のインターセプターを登録し、実際の AWS API コール中にそれらが動作するのを確認する方法を示します。

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.awscore.exception.AwsServiceException;
import software.amazon.awssdk.core.ApiName;
import software.amazon.awssdk.core.SdkRequest;
import software.amazon.awssdk.core.interceptor.Context;
import software.amazon.awssdk.core.interceptor.ExecutionAttributes;
import software.amazon.awssdk.core.interceptor.ExecutionInterceptor;
import software.amazon.awssdk.http.SdkHttpRequest;
import software.amazon.awssdk.http.SdkHttpResponse;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.model.HeadBucketRequest;
import software.amazon.awssdk.services.s3.model.ListBucketsResponse;

import java.time.Duration;
import java.time.Instant;

public class S3InterceptorsDemo {
    private static final Logger logger = LoggerFactory.getLogger(S3InterceptorsDemo.class);

    public static void main(String[] args) {
        logger.info("=== AWS SDK for Java v2 - S3 Interceptors Demo ===");

        // Create an S3 client with multiple interceptors.
        S3Client s3Client = S3Client.builder()
            .overrideConfiguration(config -> config
                .addExecutionInterceptor(new TimingInterceptor())
                .addExecutionInterceptor(new LoggingInterceptor())
                .addExecutionInterceptor(new RequestModificationInterceptor()))
            .build();

        try {
            logger.info("🚀 Starting S3 operations with interceptors...");

            // Operation 1: List buckets.
            logger.info("📋 Operation 1: Listing S3 buckets");
            logger.info("----------------------------------------");
            ListBucketsResponse listBucketsResponse = s3Client.listBuckets();
            logger.info("✅ Found {} buckets", listBucketsResponse.buckets().size());

            // Operation 2: Try to access a bucket that likely doesn't exist.
            logger.info("🔍 Operation 2: Checking non-existent bucket (demonstrating error interceptor)");
            logger.info("----------------------------------------");
            try {
                s3Client.headBucket(HeadBucketRequest.builder()
                    .bucket("amzn-s3-demo-bucket-that-does-not-exist-1234")
                    .build());
            } catch (Exception e) {
                logger.info("Expected error occurred (interceptor should have logged it)");
            }

        } catch (Exception e) {
            logger.error("❌ Error during S3 operations: {}", e.getMessage(), e);
        } finally {
            s3Client.close();
            logger.info("🔚 Demo completed - S3 client closed");
        }
    }

    // Logging interceptor.
    private static class LoggingInterceptor implements ExecutionInterceptor {
        private static final Logger logger = LoggerFactory.getLogger(LoggingInterceptor.class);

        @Override
        public void beforeExecution(Context.BeforeExecution context, ExecutionAttributes executionAttributes) {
            logger.info("🔄 [LOGGING] Starting request: {}", context.request().getClass().getSimpleName());
        }

        @Override
        public void afterExecution(Context.AfterExecution context, ExecutionAttributes executionAttributes) {
            logger.info("✅ [LOGGING] Completed request: {}", context.request().getClass().getSimpleName());
        }

        @Override
        public void onExecutionFailure(Context.FailedExecution context, ExecutionAttributes executionAttributes) {
            logger.error("❌ [LOGGING] Request failed: {}", context.request().getClass().getSimpleName());
            if (context.exception() instanceof AwsServiceException) {
                AwsServiceException ase = (AwsServiceException) context.exception();
                if (ase.awsErrorDetails().errorCode() != null) {
                    SdkHttpResponse httpResponse = ase.awsErrorDetails().sdkHttpResponse();
                    logger.error("   HTTP Status: {}", httpResponse.statusCode());
                    logger.error("   Error Code: {}", ase.awsErrorDetails().errorCode());
                    logger.error("   Error Message: {}", ase.awsErrorDetails().errorMessage());
                }
            }
        }
    }

    // Performance timing interceptor.
    private static class TimingInterceptor implements ExecutionInterceptor {
        private static final Logger logger = LoggerFactory.getLogger(TimingInterceptor.class);
        private Instant startTime;

        @Override
        public void beforeExecution(Context.BeforeExecution context, ExecutionAttributes executionAttributes) {
            startTime = Instant.now();
            logger.info("⏱️  [TIMING] Request started at: {}", startTime);
        }

        @Override
        public void afterExecution(Context.AfterExecution context, ExecutionAttributes executionAttributes) {
            if (startTime != null) {
                Duration duration = Duration.between(startTime, Instant.now());
                logger.info("⏱️  [TIMING] Request completed in: {}ms", duration.toMillis());
            }
        }

        @Override
        public void onExecutionFailure(Context.FailedExecution context, ExecutionAttributes executionAttributes) {
            if (startTime != null) {
                Duration duration = Duration.between(startTime, Instant.now());
                logger.warn("⏱️  [TIMING] Request failed after: {}ms", duration.toMillis());
            }
        }
    }

    // Request modification interceptor
    private static class RequestModificationInterceptor implements ExecutionInterceptor {
        private static final Logger logger = LoggerFactory.getLogger(RequestModificationInterceptor.class);

        @Override
        public SdkRequest modifyRequest(Context.ModifyRequest context, ExecutionAttributes executionAttributes) {
            SdkRequest originalRequest = context.request();
            logger.info("🔧 [MODIFY] Modifying request: {}", originalRequest.getClass().getSimpleName());

            // For ListBucketsRequest, we can't modify much since it has no settable properties
            // For HeadBucketRequest, we can demonstrate modifying the request
            if (originalRequest instanceof HeadBucketRequest) {
                HeadBucketRequest headRequest = (HeadBucketRequest) originalRequest;

                // Create a new request with an API name added.
                return HeadBucketRequest.builder()
                        .bucket(headRequest.bucket())
                        .overrideConfiguration(b -> b.addApiName(ApiName.builder()
                                .name("My-API")
                                .version("1.0")
                                .build()))
                        .build();
            }
            logger.info("Not a HeadBucketRequest, returning original request");
            return originalRequest;
        }

        @Override
        public SdkHttpRequest modifyHttpRequest(Context.ModifyHttpRequest context, ExecutionAttributes executionAttributes) {
            logger.info("🔧 [MODIFY] Adding custom HTTP headers");
            return context.httpRequest().toBuilder()
                .putHeader("X-Custom-Header", "S3InterceptorDemo")
                .putHeader("X-Request-ID", java.util.UUID.randomUUID().toString())
                .build();
        }
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
         http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    
    <groupId>org.example</groupId>
    <artifactId>interceptors-examples</artifactId>
    <version>1.0.0</version>
    <packaging>jar</packaging>
    
    <name>interceptors-examples</name>
    <description>Demonstration of execution interceptors in AWS SDK for Java v2</description>
    
    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <aws.java.sdk.version>2.31.62</aws.java.sdk.version>
        <exec.mainClass>org.example.S3InterceptorsDemo</exec.mainClass>
    </properties>
    
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>software.amazon.awssdk</groupId>
                <artifactId>bom</artifactId>
                <version>${aws.java.sdk.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-bom</artifactId>
                <version>2.23.1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    
    <dependencies>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>s3</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>2.0.13</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-slf4j2-impl</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-1.2-api</artifactId>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter</artifactId>
            <version>5.10.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    
    <build>
        <plugins>
            <!-- Compiler Plugin -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.11.0</version>
                <configuration>
                    <source>17</source>
                    <target>17</target>
                </configuration>
            </plugin>
            
            <!-- Surefire Plugin for running tests -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>3.2.2</version>
            </plugin>
            
            <!-- Exec Plugin for running the main class -->
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>3.1.0</version>
                <configuration>
                    <mainClass>${exec.mainClass}</mainClass>
                </configuration>
            </plugin>
            
            <!-- Shade Plugin to create executable JAR -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.4.1</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <transformers>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>${exec.mainClass}</mainClass>
                                </transformer>
                            </transformers>
                            <createDependencyReducedPom>false</createDependencyReducedPom>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

ベストプラクティス

コンテキストオブジェクト

各インターセプターメソッドは、実行のさまざまな段階でリクエストおよびレスポンス情報へのアクセスを提供するコンテキストオブジェクトを受け取ります。