feature/json_schema_validation: implement props config schema

one props example:
json.schema.validation.rules=POST|PUT:/obp/v4.0.0|v3.1.0/banks/BANK_ID/fx
/obp/v4.0.0|v3.1.0/banks/BANK_ID/fx={"$schema":"http://json-schema.org/draft-07/schema","description":"The fix","examples":[{"bank_id":"gh.29.uk","from_currency_code":"EUR","to_currency_code":"USD","conversion_value":1.136305,"inverse_conversion_value":0.8800454103431737,"effective_date":"2017-09-19T00:00:00Z"}],"required":["bank_id","from_currency_code","to_currency_code","conversion_value","inverse_conversion_value","effective_date"],"title":"The Fix schema","type":"object","properties":{"bank_id":{"$id":"#/properties/bank_id","type":"string","title":"The bank_id schema","description":"An explanation about the purpose of this instance.","default":"","examples":["gh.29.uk"]},"from_currency_code":{"$id":"#/properties/from_currency_code","default":"","description":"An explanation about the purpose of this instance.","examples":["EUR"],"title":"The from_currency_code schema","enum":["EUR","YUAN"],"type":"string"},"to_currency_code":{"$id":"#/properties/to_currency_code","default":"","description":"An explanation about the purpose of this instance.","examples":["USD"],"title":"The to_currency_code schema","enum":["USD","YUAN"],"type":"string"},"conversion_value":{"$id":"#/properties/conversion_value","type":"number","title":"The conversion_value schema","description":"An explanation about the purpose of this instance.","default":0.0,"examples":[1.136305]},"inverse_conversion_value":{"$id":"#/properties/inverse_conversion_value","type":"number","title":"The inverse_conversion_value schema","description":"An explanation about the purpose of this instance.","default":0.0,"examples":[0.8800454103431737]},"effective_date":{"$id":"#/properties/effective_date","type":"string","title":"The effective_date schema","description":"An explanation about the purpose of this instance.","default":"","examples":["2017-09-19T00:00:00Z"]}},"additionalProperties":true}

obp-api/pom.xml

@@ -462,6 +462,13 @@
       <version>1.7.0</version>
     </dependency>
 
+    <!--json schema validation start-->
+    <dependency>
+      <groupId>com.networknt</groupId>
+      <artifactId>json-schema-validator</artifactId>
+      <version>1.0.45</version>
+    </dependency>
+    <!--json schema validation end-->
   </dependencies>
 
   <build>

obp-api/src/main/scala/code/api/OBPRestHelper.scala

@@ -41,17 +41,21 @@ import code.api.v4_0_0.APIMethods400
 import code.model.dataAccess.AuthUser
 import code.util.Helper.MdcLoggable
 import com.alibaba.ttl.TransmittableThreadLocal
+import com.fasterxml.jackson.databind.{JsonNode, ObjectMapper}
+import com.networknt.schema.{JsonSchema, JsonSchemaFactory, SpecVersionDetector, ValidationMessage}
 import com.openbankproject.commons.model.ErrorMessage
-import com.openbankproject.commons.util.{ApiVersion, ReflectUtils, ScannedApiVersion}
+import com.openbankproject.commons.util.{ApiVersion, Functions, ReflectUtils, ScannedApiVersion}
 import net.liftweb.common._
 import net.liftweb.http.rest.RestHelper
-import net.liftweb.http.{JsonResponse, LiftResponse, Req, S}
+import net.liftweb.http.{BadRequestResponse, JsonResponse, LiftResponse, Req, S}
 import net.liftweb.json.Extraction
 import net.liftweb.json.JsonAST.JValue
 import net.liftweb.util.Helpers
+import org.apache.commons.lang3.StringUtils
 
 import scala.collection.immutable.List
 import scala.collection.mutable.ArrayBuffer
+import scala.jdk.CollectionConverters.iterableAsScalaIterableConverter
 import scala.math.Ordering
 
 trait APIFailure{
@@ -424,12 +428,98 @@ trait OBPRestHelper extends RestHelper with MdcLoggable {
     serve(obpHandler)
   }
 
+  case class JsonSchemaValidator(methods: Array[String], url: String, schema: String) {
+    import JsonSchemaValidator._
+
+    private val methodSet: Set[String] = methods.map(_.trim.toUpperCase)
+        .filter(requestMethods.contains(_))
+        .toSet
+
+    assert(methodSet.nonEmpty, s"json schema validation rules contains illegal methods: ${methods.mkString("|")}:$url")
+
+    private val jsonSchema: JsonSchema = {
+      val schemaJson: JsonNode = mapper.readTree(schema)
+      val factory = JsonSchemaFactory.getInstance(SpecVersionDetector.detect(schemaJson))
+      factory.getSchema(schemaJson)
+    }
+
+    private val urlPartMatchers: Array[String => Boolean] = {
+      StringUtils.split(url, '/').map {
+        case v if v.contains('|') => // or style: v3.1.0|v4.0.0
+          val parts = StringUtils.split(v, "|")
+          parts.contains(_:String)
+        case v if v.forall(it => it < 'a' || it > 'z' ) => // placeholder style: BANK_ID
+          Functions.truePredicate[String]
+        case v =>
+          v == _
+      }
+    }
+
+    def isRequestMatches(method: String, requestUrl: List[String]): Boolean = {
+      methodSet.contains(method) &&
+        requestUrl.size == urlPartMatchers.size && {
+        urlPartMatchers.zip(requestUrl).forall(it => {
+          val (fun, v) = it
+          fun(v)
+        })
+      }
+    }
+
+    def validatePayload(jsonContent: Array[Byte]): java.util.Set[ValidationMessage] = {
+      val zson = mapper.readTree(jsonContent)
+       jsonSchema.validate(zson)
+    }
+
+  }
+
+  object JsonSchemaValidator {
+    private val mapper = new ObjectMapper
+    // regex, match this format string: "GET|POST|PUTV:/obp/v4.0.0|v3.1.0/banks/BANK_ID/fx"
+    // group 1 is http method names, group 2 is url
+    private val regex = """([|a-zA-Z]+?):([^,]+)""".r
+    private val requestMethods = Set(
+      "POST","PUT","DELETE","GET","HEAD","PATCH","TRACE","OPTIONS","CONNECT"
+    )
+
+    // create JsonSchemaValidator with structured string, style like:
+    // PUT|POST:/obp/v4.0.0|v3.1.0/banks/BANK_ID/fx
+    def apply(toParseRule: String): JsonSchemaValidator = toParseRule match {
+      case regex(methods , url) =>
+        val schemaStr = APIUtil.getPropsValue(url).openOrThrowException(s"key '$url' is not found in props file, it is mandatory for 'json.schema.validation.rules'")
+        JsonSchemaValidator(StringUtils.split(methods, "|"), url, schemaStr)
+      case v => throw new RuntimeException(s"props 'json.schema.validation.rules' value contains illegal part: $v")
+    }
+  }
+
+  private val jsonSchemaRuleMatchers: Array[JsonSchemaValidator] = {
+    APIUtil.getPropsValue("json.schema.validation.rules") match {
+      case Full(v) =>
+        StringUtils.split(v,",").map(JsonSchemaValidator(_))
+      case _ => Array.empty[JsonSchemaValidator]
+    }
+  }
+
   override protected def serve(handler: PartialFunction[Req, () => Box[LiftResponse]]) : Unit = {
     val obpHandler : PartialFunction[Req, () => Box[LiftResponse]] = {
       new PartialFunction[Req, () => Box[LiftResponse]] {
-        def apply(r : Req) = {
-          //Wraps the partial function with some logging
-          handler(r)
+        def apply(r : Req): () => Box[LiftResponse] = {
+
+          val validationError: Box[String] = for {
+            body <- r.body
+            validator <- jsonSchemaRuleMatchers.find(_.isRequestMatches(r.requestType.method, r.path.partPath))
+            errors: Iterable[ValidationMessage] = validator.validatePayload(body).asScala
+            if errors.nonEmpty
+          } yield errors.mkString("; ")
+
+          validationError match {
+            case Full(errorInfo) =>
+              val errorResponse = s"""{"code":400,"message":"${ErrorMessages.InvalidRequestPayload} $errorInfo"}"""
+              () =>  Full(BadRequestResponse(errorResponse))
+            case _ =>
+              //Wraps the partial function with some logging
+              handler(r)
+          }
+
         }
         def isDefinedAt(r : Req) = handler.isDefinedAt(r)
       }

obp-api/src/main/scala/code/api/util/ErrorMessages.scala

@@ -56,6 +56,7 @@ object ErrorMessages {
   val InvalidMyDynamicEndpointUser = "OBP-09011: DynamicEndpoint can only be updated/deleted by the user who created it. Please try `Update/DELETE Dynamic Endpoint` endpoint"
   
   val InvalidBankIdDynamicEntity = "OBP-09012: This is a bank level dynamic entity. Please specify a valid value for BANK_ID."
+  val InvalidRequestPayload = "OBP-09013: Request body is invalid json structure."
 
 
   // General messages (OBP-10XXX)