Validate JSON Schema

Abstract

• The main motto of this PPT is How to use Validate JSON Schema in our applications.

Introduction• The JSON Schema validator evaluates JSON payloads at

runtime and verifies that they match a referenced JSON schema. You can match against schemas that exist in a local file or in an external URI. If the validation fails, an exception is raised with feedback about what went wrong and a reference to the original invalid payload. The JSON Schema Validator supports schema drafts of version 4 and older.

• This feature is specially handy when exposing a service that expects JSON inputs from users that must match a specific schema. You can use it to match the incoming external calls against the expected structure.

Example

.mflow• <?xml version="1.0" encoding="UTF-8"?>

• <mule xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns:json="http://www.mulesoft.org/schema/mule/json" xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"

• xmlns:spring="http://www.springframework.org/schema/beans" • xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"• xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-current.xsd• http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd• http://www.mulesoft.org/schema/mule/json http://www.mulesoft.org/schema/mule/json/current/mule-

json.xsd• http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-

http.xsd">• <http:listener-config name="HTTP_Listener_Configuration" host="localhost" port="8087" doc:name="HTTP

Listener Configuration"/>• <flow name="JsonSchemaValidatorFlow">• <http:listener config-ref="HTTP_Listener_Configuration" path="/" doc:name="HTTP"/>• <json:validate-schema schemaLocation="Schema.json" doc:name="Validate JSON Schema"/>• <logger message="--Valid input" level="INFO" doc:name="Logger"/>• </flow>• </mule>

• Place the schema file in src/main/resources

Schema.json

• Output:• If the input is valid input:• INFO 2016-12-22 09:23:32,157

[[JsonSchemaValidator].HTTP_Listener_Configuration.worker.02] org.mule.api.processor.LoggerMessageProcessor: --Valid input

• If the input is invalid input:

• ERROR 2016-12-22 09:23:15,139 [[JsonSchemaValidator].HTTP_Listener_Configuration.worker.02] org.mule.exception.DefaultMessagingExceptionStrategy: • ********************************************************************************• Message : Json content is not compliant with schema• com.github.fge.jsonschema.core.report.ListProcessingReport: failure• --- BEGIN MESSAGES ---• error: object has missing required properties (["firstName"])• level: "error"• schema: {"loadingURI":"file:/C:/Users/sivachandra.mandalap/AnypointStudio/workspace1/.mule/apps/JsonSchemaValidator/classes/Schema.json#","pointer":""}• instance: {"pointer":""}• domain: "validation"• keyword: "required"• required: ["firstName","lastName"]• missing: ["firstName"]• --- END MESSAGES ---

• Payload : {"lastName":"def","age":10}• Payload Type : java.lang.String• Element : /JsonSchemaValidatorFlow/processors/0 @ JsonSchemaValidator• --------------------------------------------------------------------------------• Root Exception stack trace:• org.mule.module.json.validation.JsonSchemaValidationException: Json content is not compliant with schema• com.github.fge.jsonschema.core.report.ListProcessingReport: failure• --- BEGIN MESSAGES ---• error: object has missing required properties (["firstName"])• level: "error"• schema: {"loadingURI":"file:/C:/Users/sivachandra.mandalap/AnypointStudio/workspace1/.mule/apps/JsonSchemaValidator/classes/Schema.json#","pointer":""}• instance: {"pointer":""}• domain: "validation"• keyword: "required"• required: ["firstName","lastName"]• missing: ["firstName"]• --- END MESSAGES ---

• at org.mule.module.json.validation.JsonSchemaValidator.validate(JsonSchemaValidator.java:286)• at org.mule.module.json.validation.ValidateJsonSchemaMessageProcessor.process(ValidateJsonSchemaMessageProcessor.java:46)• at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)• at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:108)• at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:44)

• Flow of execution:1. URL to trigger the service from browser

References

• https://docs.mulesoft.com/mule-user-guide/v/3.8/json-schema-validator