software.amazon.lambda.powertools.validation

Annotation Type Validation

@Retention(value=RUNTIME)
 @Target(value=METHOD)
public @interface Validation

Validation is used to specify that the annotated method input and/or output needs to be valid.

Validation should be used on the RequestHandler.handleRequest(Object, Context) or RequestStreamHandler.handleRequest(InputStream, OutputStream, Context) methods.

Using the Java language, RequestHandler input and output are already strongly typed, and if a json event cannot be deserialize to the specified object, invocation will either fail or retrieve a partial event. More information in the documentation (java-handler).

But when using built-in types from the aws-lambda-java-events library, such as APIGatewayProxyRequestEvent or SQSEvent, using the Validation annotation will permit to validate the underlying content, for example the body of an API Gateway request, or the records body of an SQS event.

Validation has built-in validation for the following input types:

Type of event	Class	Path to content
API Gateway REST	APIGatewayProxyRequestEvent	body
API Gateway HTTP	APIGatewayV2HTTPEvent	body
Cloudformation Custom Resource	CloudFormationCustomResourceEvent	resourceProperties
CloudWatch Logs	CloudWatchLogsEvent	awslogs.powertools_base64_gzip(data)
EventBridge / Cloudwatch	ScheduledEvent	detail
Kafka	KafkaEvent	records[*][*].value
Kinesis	KinesisEvent	Records[*].kinesis.powertools_base64(data)
Kinesis Firehose	KinesisFirehoseEvent	Records[*].powertools_base64(data)
Kinesis Analytics from Firehose	KinesisAnalyticsFirehoseInputPreprocessingEvent	Records[*].powertools_base64(data)
Kinesis Analytics from Streams	KinesisAnalyticsStreamsInputPreprocessingEvent	Records[*].powertools_base64(data)
Load Balancer	ApplicationLoadBalancerRequestEvent	body
SNS	SNSEvent	Records[*].Sns.Message
SQS	SQSEvent	Records[*].body

Validation has built-in validation for the following output types:

Type of response	Class	Path to content
API Gateway REST	APIGatewayProxyResponseEvent	body
API Gateway HTTP	APIGatewayV2HTTPResponse	body
API Gateway WebSocket	APIGatewayV2WebSocketResponse	body
Load Balancer	ApplicationLoadBalancerResponseEvent	body
Kinesis Analytics	KinesisAnalyticsInputPreprocessingResponse	Records[*].powertools_base64(data)

You can specify either inboundSchema or outboundSchema or both, depending on what you want to validate.
The schema must be passed as a json string (constant), or using the syntax "classpath:/some/path/to/schema.json" , provided that the schema.json file is available in the classpath at the specified path.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
java.lang.String	envelope path to the subelement
java.lang.String	inboundSchema schema used to validate the lambda function input
java.lang.String	outboundSchema schema used to validate the lambda function output
com.networknt.schema.SpecVersion.VersionFlag	schemaVersion json schema specification version (default is 2019-09)

Element Detail

inboundSchema

public abstract java.lang.String inboundSchema

schema used to validate the lambda function input

Default:

""

outboundSchema

public abstract java.lang.String outboundSchema

schema used to validate the lambda function output

Default:

""

envelope

public abstract java.lang.String envelope

path to the subelement

Default:

""

schemaVersion

public abstract com.networknt.schema.SpecVersion.VersionFlag schemaVersion

json schema specification version (default is 2019-09)

Default:

com.networknt.schema.SpecVersion.VersionFlag.V7