AWS Lambda Environment fails to find S3EventNotification** class. Works locally

[flipch]

aws-lambda-java-libs/aws-lambda-java-serialization/src/main/java/com/amazonaws/services/lambda/runtime/serialization/events/serializers/S3EventSerializer.java

Lines 103 to 114 in 3ab2213

	try {
	// Try to load newer version of S3EventNotification from aws-lambda-java-events v3+
	Class eventNotificationRecordClass = SerializeUtil.loadCustomerClass(
	S3_EVENT_NOTIFICATION_CLASS_V3 + "$S3EventNotificationRecord", classLoader);
	jsonObject = serializeEvent(eventNotificationRecordClass, value, S3_EVENT_NOTIFICATION_CLASS_V3);
	} catch (Exception ex) {
	// Fallback to aws-lambda-java-events pre-v3 (relies on aws-s3-sdk)
	Class eventNotificationRecordClass = SerializeUtil.loadCustomerClass(
	S3_EVENT_NOTIFICATION_CLASS_V2 + "$S3EventNotificationRecord", classLoader);
	jsonObject = serializeEvent(eventNotificationRecordClass, value, S3_EVENT_NOTIFICATION_CLASS_V2);
	}

Something seems to be failing here when trying to find the com.amazonaws.services.lambda.runtime.events.models.s3.S3EventNotification** classes as my lambda clearly has them available. I've exported from the AWS Console and extracted the jar file.

Yet I still get a runtime error when attempting to deserialize a string into an S3Event

java.lang.ClassNotFoundException: com.amazonaws.services.s3.event.S3EventNotification$S3EventNotificationRecord: com.amazonaws.services.lambda.runtime.serialization.util.ReflectUtil$ReflectException
com.amazonaws.services.lambda.runtime.serialization.util.ReflectUtil$ReflectException: java.lang.ClassNotFoundException: com.amazonaws.services.s3.event.S3EventNotification$S3EventNotificationRecord
        at com.amazonaws.services.lambda.runtime.serialization.util.ReflectUtil.loadClass(ReflectUtil.java:85)
        at com.amazonaws.services.lambda.runtime.serialization.util.SerializeUtil.loadCustomerClass(SerializeUtil.java:37)
        at com.amazonaws.services.lambda.runtime.serialization.events.serializers.S3EventSerializer.deserializeEvent(S3EventSerializer.java:157)
        at com.amazonaws.services.lambda.runtime.serialization.events.serializers.S3EventSerializer.fromJson(S3EventSerializer.java:93)

Or when instantiating an deserializer for S3EventNotificationRecord

java.lang.ClassNotFoundException: org.joda.time.DateTime: com.amazonaws.services.lambda.runtime.serialization.util.ReflectUtil$ReflectException
com.amazonaws.services.lambda.runtime.serialization.util.ReflectUtil$ReflectException: java.lang.ClassNotFoundException: org.joda.time.DateTime
        at com.amazonaws.services.lambda.runtime.serialization.util.ReflectUtil.loadClass(ReflectUtil.java:85)
        at com.amazonaws.services.lambda.runtime.serialization.util.SerializeUtil.loadCustomerClass(SerializeUtil.java:37)
        at com.amazonaws.services.lambda.runtime.serialization.events.modules.DateTimeModule.<init>(DateTimeModule.java:28)
        at com.amazonaws.services.lambda.runtime.serialization.events.LambdaEventSerializers.serializerFor(LambdaEventSerializers.java:248)
        ```

[flipch]

The issue seems to revolve around the lambda's environment class loader not functioning properly.

The solution was to change the passed in class loader, i.e from
this.s3EventSerializer = LambdaEventSerializers.serializerFor(S3EventNotification.class, ClassLoader.getSystemClassLoader();
to
this.s3EventSerializer = LambdaEventSerializers.serializerFor(S3EventNotification.class, Thread.currentThread().getContextClassLoader());

[kedarundale17]

@flipch I faced the same issue , the above mentioned solution works like a charm.
Thanks

[marczis]

Hello, I'm not supposed to see this in 2023 right? Or.... :)

[shinusuresh]

2024 yey