Feature/305 improve cron (#423)

* Tried with two separate libraries

* Remove other cron libraries

* Use verbose mode

Author: kevinwallimann

pom.xml

@@ -104,7 +104,7 @@
         <scalatest.version>3.0.5</scalatest.version>
         <h2database.version>1.4.200</h2database.version>
         <mockito.version>2.25.0</mockito.version>
-        <cronutils.version>9.1.3</cronutils.version>
+        <cron-expression-descriptor.version>1.2</cron-expression-descriptor.version>
         <node.version>12.14.1</node.version>
         <npm.version>6.13.4</npm.version>
         <scala-maven-plugin.version>3.2.1</scala-maven-plugin.version>
@@ -213,9 +213,9 @@
             <version>${spring.ldap.version}</version>
         </dependency>
         <dependency>
-            <groupId>com.cronutils</groupId>
-            <artifactId>cron-utils</artifactId>
-            <version>${cronutils.version}</version>
+            <groupId>it.burning</groupId>
+            <artifactId>cron-expression-descriptor</artifactId>
+            <version>${cron-expression-descriptor.version}</version>
         </dependency>
         <dependency>
             <groupId>org.liquibase</groupId>

src/main/scala/za/co/absa/hyperdrive/trigger/api/rest/controllers/UtilController.scala

@@ -15,31 +15,30 @@
 
 package za.co.absa.hyperdrive.trigger.api.rest.controllers
 
-import java.util.Locale
-
-import com.cronutils.descriptor.CronDescriptor
-import com.cronutils.model.CronType
-import com.cronutils.model.definition.CronDefinitionBuilder
-import com.cronutils.parser.CronParser
+import it.burning.cron.CronExpressionParser.{CronExpressionParseException, Options}
+import it.burning.cron.CronExpressionDescriptor
 import org.springframework.web.bind.annotation._
 import za.co.absa.hyperdrive.trigger.models.QuartzExpressionDetail
 
+import java.util.Locale
+
 @RestController
 class UtilController {
-  val parser: CronParser = new CronParser(CronDefinitionBuilder.instanceDefinitionFor(CronType.QUARTZ))
-  val descriptor: CronDescriptor = CronDescriptor.instance(Locale.UK)
 
   @GetMapping(path = Array("/util/quartzDetail"))
   def getQuartzDetail(@RequestParam expression: String): QuartzExpressionDetail = {
     try {
-      val expressionDescription = descriptor.describe(parser.parse(expression))
+      val description = CronExpressionDescriptor.getDescription(expression, new Options() {{
+        setLocale(Locale.UK)
+        setVerbose(true)
+      }})
       QuartzExpressionDetail(
         expression = expression,
         isValid = true,
-        explained = expressionDescription
+        explained = description
       )
     } catch {
-      case e: IllegalArgumentException => {
+      case e: CronExpressionParseException => {
         QuartzExpressionDetail(
           expression = expression,
           isValid = false,
@@ -48,5 +47,4 @@ class UtilController {
       }
     }
   }
-
 }

src/test/scala/za/co/absa/hyperdrive/trigger/api/rest/controller/UtilControllerTest.scala

@@ -0,0 +1,65 @@
+
+/*
+ * Copyright 2018 ABSA Group Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package za.co.absa.hyperdrive.trigger.api.rest.controller
+
+import org.scalatest.mockito.MockitoSugar
+import org.scalatest.{BeforeAndAfter, FlatSpec, Matchers}
+import za.co.absa.hyperdrive.trigger.api.rest.controllers.UtilController
+
+class UtilControllerTest extends FlatSpec with Matchers with MockitoSugar with BeforeAndAfter {
+  private val underTest = new UtilController
+
+  "getQuartzDetail" should "return a human-readable description, incl. month" in {
+    // given
+    val expression = "0 0 2 2 * ?"
+
+    // when
+    val result = underTest.getQuartzDetail(expression)
+
+    // then
+    result.expression shouldBe expression
+    result.isValid shouldBe true
+    result.explained shouldBe "At 02:00, on day 2 of the month"
+  }
+
+  it should "return a verbose human-readable description" in {
+    // given
+    val expression = "0 0/20 * ? * * *"
+
+    // when
+    val result = underTest.getQuartzDetail(expression)
+
+    // then
+    result.expression shouldBe expression
+    result.isValid shouldBe true
+    result.explained shouldBe "Every 20 minutes, every hour, every day"
+  }
+
+  it should "return an error description if the cron expression is malformed" in {
+    // given
+    val expression = "0 0 2 2 * MON"
+
+    // when
+    val result = underTest.getQuartzDetail(expression)
+
+    // then
+    result.expression shouldBe expression
+    result.isValid shouldBe false
+    result.explained shouldBe "Specifying both a Day of Month and Day of Week is not supported. Either one or the other should be declared as \"?\""
+  }
+
+}