AWS Lambda S3Event deserialization

Question

Has anyone successfully implemented a Java based request handler for S3 events?

My class:

package example;

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.s3.model.S3Event;

public class Hello implements RequestHandler<S3Event, String> {
    public String handleRequest(S3Event event, Context context) {
        return "Success";
    }
}

Error message:

An error occurred during JSON parsing: java.lang.RuntimeException java.lang.RuntimeException: An error occurred during JSON parsing Caused by: java.io.UncheckedIOException: com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of com.amazonaws.services.s3.model.S3Event out of START_OBJECT token at [Source: lambdainternal.util.NativeMemoryAsInputStream@6108b2d7; line: 1, column: 1] Caused by: com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of com.amazonaws.services.s3.model.S3Event out of START_OBJECT token at [Source: lambdainternal.util.NativeMemoryAsInputStream@6108b2d7; line: 1, column: 1] at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:148) at com.fasterxml.jackson.databind.DeserializationContext.mappingException(DeserializationContext.java:835) at com.fasterxml.jackson.databind.DeserializationContext.mappingException(DeserializationContext.java:831) at com.fasterxml.jackson.databind.deser.std.EnumDeserializer._deserializeOther(EnumDeserializer.java:137) at com.fasterxml.jackson.databind.deser.std.EnumDeserializer.deserialize(EnumDeserializer.java:89) at com.fasterxml.jackson.databind.deser.std.EnumDeserializer.deserialize(EnumDeserializer.java:18) at com.fasterxml.jackson.databind.ObjectReader._bindAndClose(ObjectReader.java:1441) at com.fasterxml.jackson.databind.ObjectReader.readValue(ObjectReader.java:1047)

Answer 1

The solution was to take S3EventNotification. Wish that was covered in the AWS documentation. I like the Lambda concept but there is not much for documentation or examples out there.

public void mergeGLAU(S3EventNotification notification, Context context) {
    try {
        for (S3EventNotificationRecord record : notification.getRecords()) {
            System.out.println(record.getEventSource());
            System.out.println(record.getEventName());
            System.out.println(record.getS3().getBucket().getName());
            System.out.println(record.getS3().getObject().getKey());
        }
    }
    catch (Exception e) {
        e.printStackTrace();
    }
}