Error in dynamoDB mapper scan() : java.lang.NullPointerException: null

Question

I am getting below error while calling

dynamoDBMapper.scan(Person.class, new DynamoDBScanExpression())

java.lang.NullPointerException: null
    at com.amazonaws.services.dynamodbv2.model.ScanRequest.setScanFilter(ScanRequest.java)
    at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.createScanRequestFromExpression(DynamoDBMapper.java:1692)
    at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.scan(DynamoDBMapper.java:1569)
    at com.amazonaws.services.dynamodbv2.datamodeling.AbstractDynamoDBMapper.scan(AbstractDynamoDBMapper.java:236)

With the same dynamoDBMapper, dynamoDBMapper.save(person1) is working fine.

The NullPointerExecption is coming inside of ScanRequest.setScanFilter method of the AWS SDK.

Although, the method setScanFilter has only one line of code, the stacktrace is not showing the line-number where the exception occurred.

The method ScanRequest.setScanFilter looks like this.

public void setScanFilter(java.util.Map<String, Condition> scanFilter) {
    this.scanFilter = scanFilter;
}

Not sure how this.scanFilter = scanFilter can cause a NullPointerException

• Spring Boot - 2.2.6.RELEASE
• DynamoDB SDK - 1.11.555
• Java - Corretto-8.242.08.1

Answer 1

@ShrinivasShukla I also found the NPE when Contrast is wired up in Application. In my case Probably Contrast is disabling/blocking scanRequest.setScanFilter(scanExpression.getScanFilter() to work.