[INFRA] Improve the java style checks log the errors to sbt console

build.sbt

@@ -17,6 +17,7 @@
 // scalastyle:off line.size.limit
 
 import java.nio.file.Files
+import Checkstyle._
 import Mima._
 import Unidoc._
 
@@ -1309,44 +1310,6 @@ lazy val kernelGroup = project
     }
   ).configureUnidoc(docTitle = "Delta Kernel")
 
-/*
- ***********************
- * ScalaStyle settings *
- ***********************
- */
-ThisBuild / scalastyleConfig := baseDirectory.value / "scalastyle-config.xml"
-
-lazy val compileScalastyle = taskKey[Unit]("compileScalastyle")
-lazy val testScalastyle = taskKey[Unit]("testScalastyle")
-
-lazy val scalaStyleSettings = Seq(
-  compileScalastyle := (Compile / scalastyle).toTask("").value,
-
-  Compile / compile := ((Compile / compile) dependsOn compileScalastyle).value,
-
-  testScalastyle := (Test / scalastyle).toTask("").value,
-
-  Test / test := ((Test / test) dependsOn testScalastyle).value
-)
-
-/*
- ****************************
- * Java checkstyle settings *
- ****************************
- */
-
-def javaCheckstyleSettings(checkstyleFile: String): Def.SettingsDefinition = {
-  // Can be run explicitly via: build/sbt $module/checkstyle
-  // Will automatically be run during compilation (e.g. build/sbt compile)
-  // and during tests (e.g. build/sbt test)
-  Seq(
-    checkstyleConfigLocation := CheckstyleConfigLocation.File(checkstyleFile),
-    checkstyleSeverityLevel := CheckstyleSeverityLevel.Error,
-    (Compile / compile) := ((Compile / compile) dependsOn (Compile / checkstyle)).value,
-    (Test / test) := ((Test / test) dependsOn (Test / checkstyle)).value
-  )
-}
-
 /*
  ********************
  * Release settings *

project/Checkstyle.scala

@@ -0,0 +1,103 @@
+/*
+ * Copyright (2024) The Delta Lake Project Authors.
+ *
+ * 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.
+ */
+
+import com.etsy.sbt.checkstyle.CheckstylePlugin.autoImport._
+import org.scalastyle.sbt.ScalastylePlugin.autoImport._
+import sbt._
+import sbt.Keys._
+
+object Checkstyle {
+
+  /*
+   *****************************
+   * Scala checkstyle settings *
+   *****************************
+   */
+
+  ThisBuild / scalastyleConfig := baseDirectory.value / "scalastyle-config.xml"
+
+  private lazy val compileScalastyle = taskKey[Unit]("compileScalastyle")
+  private lazy val testScalastyle = taskKey[Unit]("testScalastyle")
+
+  lazy val scalaStyleSettings = Seq(
+    compileScalastyle := (Compile / scalastyle).toTask("").value,
+
+    Compile / compile := ((Compile / compile) dependsOn compileScalastyle).value,
+
+    testScalastyle := (Test / scalastyle).toTask("").value,
+
+    Test / test := ((Test / test) dependsOn testScalastyle).value
+  )
+
+  /*
+   ****************************
+   * Java checkstyle settings *
+   ****************************
+   */
+
+  private lazy val compileJavastyle = taskKey[Unit]("compileJavastyle")
+  private lazy val testJavastyle = taskKey[Unit]("testJavastyle")
+
+  def javaCheckstyleSettings(checkstyleFile: String): Def.SettingsDefinition = {
+    // Can be run explicitly via: build/sbt $module/checkstyle
+    // Will automatically be run during compilation (e.g. build/sbt compile)
+    // and during tests (e.g. build/sbt test)
+    Seq(
+      checkstyleConfigLocation := CheckstyleConfigLocation.File(checkstyleFile),
+      // if we keep the Error severity, `build/sbt` will throw an error and immediately stop at
+      // the `checkstyle` phase (if error) -> never execute the `check-report` phase of
+      // `checkstyle-report.xml` and `checkstyle-test-report.xml`. We need to ignore and throw
+      // error if exists when checking *report.xml.
+      checkstyleSeverityLevel := CheckstyleSeverityLevel.Ignore,
+
+      compileJavastyle := {
+        (Compile / checkstyle).value
+        javaCheckstyle(streams.value.log, checkstyleOutputFile.value)
+      },
+      (Compile / compile) := ((Compile / compile) dependsOn compileJavastyle).value,
+
+      testJavastyle := {
+        (Test / checkstyle).value
+        javaCheckstyle(streams.value.log, (Compile / target).value / "checkstyle-test-report.xml")
+      },
+      (Test / test) := ((Test / test) dependsOn (Test / testJavastyle)).value
+    )
+  }
+
+  private def javaCheckstyle(log: Logger, reportFile: File): Unit = {
+    val report = scala.xml.XML.loadFile(reportFile)
+
+    val errors = (report \\ "file").flatMap { fileNode =>
+      val file = fileNode.attribute("name").get.head.text
+      (fileNode \ "error").map { error =>
+        val line = error.attribute("line").get.head.text
+        val message = error.attribute("message").get.head.text
+        (file, line, message)
+      }
+    }
+
+    if (errors.nonEmpty) {
+      var errorMsg = "Found checkstyle errors"
+      errors.foreach { case (file, line, message) =>
+        val lineError = s"File: $file, Line: $line, Message: $message"
+        log.error(lineError)
+        errorMsg += ("\n" + lineError)
+      }
+      sys.error(errorMsg + "\n")
+    }
+  }
+
+}