Jackson objectMapper mixin to convert lambda InputStream to DynamodbEvent object. Values found on this issue were out of date/incomplete -> https://github.com/aws/aws-sdk-java/issues/1344

DynamodbEventMixin.java

import com.fasterxml.jackson.annotation.JsonProperty;

import java.nio.ByteBuffer;
import java.util.Date;
import java.util.List;
import java.util.Map;

public abstract class DynamodbEventMixin {

    @JsonProperty("Records") abstract List<?> getRecords();
    @JsonProperty("Records") abstract void setRecords(List<?> records);

    public abstract class DynamodbStreamRecordMixin {
        @JsonProperty("EventID") abstract String getEventID();
        @JsonProperty("EventID") abstract void setEventID(String var1);

        @JsonProperty("EventName") abstract String getEventName();
        @JsonProperty("EventName") abstract void setEventName(String eventName);

        @JsonProperty("EventVersion") abstract String getEventVersion();
        @JsonProperty("EventVersion") abstract void setEventVersion(String eventVersion);

        @JsonProperty("EventSource") abstract String getEventSource();
        @JsonProperty("EventSource") abstract void setEventSource(String eventSource);

        @JsonProperty("AwsRegion") abstract String getAwsRegion();
        @JsonProperty("AwsRegion") abstract void setAwsRegion(String awsRegion);

        @JsonProperty("Dynamodb") abstract Object getDynamodb();
        @JsonProperty("Dynamodb") abstract void setDynamodb(Object dynamodb);

        @JsonProperty("EventSourceARN") abstract String getEventSourceArn();
        @JsonProperty("EventSourceARN") abstract void setEventSourceArn(String eventSourceArn);
    }

    public abstract class StreamRecordMixin {
        @JsonProperty("Keys") abstract Map<String, ?> getKeys();
        @JsonProperty("Keys") abstract void setKeys(Map<String, ?> keys);

        @JsonProperty("SizeBytes") abstract Long getSizeBytes();
        @JsonProperty("SizeBytes") abstract void setSizeBytes(Long sizeBytes);

        @JsonProperty("SequenceNumber") abstract String getSequenceNumber();
        @JsonProperty("SequenceNumber") abstract void setSequenceNumber(String sequenceNumber);

        @JsonProperty("StreamViewType") abstract String getStreamViewType();
        @JsonProperty("StreamViewType") abstract void setStreamViewType(String streamViewType);

        @JsonProperty("NewImage") abstract Map<String, ?> getNewImage();
        @JsonProperty("NewImage") abstract void setNewImage(Map<String, ?> newImage);

        @JsonProperty("OldImage") abstract Map<String, ?> getOldImage();
        @JsonProperty("OldImage") abstract void setOldImage(Map<String, ?> oldImage);

        @JsonProperty("ApproximateCreationDateTime") abstract Date getApproximateCreationDateTime();
        @JsonProperty("ApproximateCreationDateTime") abstract void setApproximateCreationDateTime(Date approximateCreationDateTime);

    }

    public abstract class AttributeValueMixin {
        @JsonProperty("S") abstract String getS();
        @JsonProperty("S") abstract void setS(String s);

        @JsonProperty("N") abstract String getN();
        @JsonProperty("N") abstract void setN(String n);

        @JsonProperty("B") abstract ByteBuffer getB();
        @JsonProperty("B") abstract void setB(ByteBuffer b);

        @JsonProperty("NULL") abstract Boolean isNULL();
        @JsonProperty("NULL") abstract void setNULL(Boolean nU);

        @JsonProperty("BOOL") abstract Boolean getBOOL();
        @JsonProperty("BOOL") abstract void setBOOL(Boolean bO);

        @JsonProperty("SS") abstract List<String> getSS();
        @JsonProperty("SS") abstract void setSS(List<String> sS);

        @JsonProperty("NS") abstract List<String> getNS();
        @JsonProperty("NS") abstract void setNS(List<String> nS);

        @JsonProperty("BS") abstract List<String> getBS();
        @JsonProperty("BS") abstract void setBS(List<String> bS);

        @JsonProperty("M") abstract Map<String, ?> getM();
        @JsonProperty("M") abstract void setM(Map<String, ?> val);

        @JsonProperty("L") abstract List<?> getL();
        @JsonProperty("L") abstract void setL(List<?> val);

    }
}