[KYUUBI #7723][UTIL] Answer false from isClassLoadable when the class fails to link or initialize

kyuubi-util-scala/src/main/scala/org/apache/kyuubi/util/reflect/ReflectUtils.scala

@@ -22,22 +22,28 @@ import java.util.ServiceLoader
 import scala.collection.JavaConverters._
 import scala.language.existentials
 import scala.reflect.ClassTag
-import scala.util.Try
 
 object ReflectUtils {
 
   /**
-   * Determines whether the provided class is loadable
+   * Determines whether the provided class is loadable, answering false when it cannot
+   * be found, linked, or initialized.
    * @param className the class name
    * @param cl the class loader
    * @return is the class name loadable with the class loader
    */
   def isClassLoadable(
       className: String,
       cl: ClassLoader = Thread.currentThread().getContextClassLoader): Boolean =
-    Try {
+    try {
       DynClasses.builder().loader(cl).impl(className).buildChecked()
-    }.isSuccess
+      true
+    } catch {
+      // scala.util.Try does not catch LinkageError, so a class that fails to link or
+      // initialize would escape the probe instead of answering false
+      case _: ClassNotFoundException => false
+      case _: LinkageError => false
+    }
 
   /**
    * get the field value of the given object

kyuubi-util-scala/src/test/scala/org/apache/kyuubi/util/reflect/ReflectUtilsSuite.scala

@@ -32,6 +32,15 @@ class ReflectUtilsSuite extends AnyFunSuite {
     assert(!isClassLoadable("org.apache.kyuubi.NonExistClass"))
   }
 
+  test("check class that fails to initialize is not loadable") {
+    // Class.forName reports a failing static initializer as ExceptionInInitializerError,
+    // a LinkageError that Try does not catch; a loadability probe must answer false
+    // instead of letting the error escape
+    // probe by binary name: touching the object reference would run the failing
+    // initialization outside the code under test and abort the suite
+    assert(!isClassLoadable("org.apache.kyuubi.util.reflect.FailingInit$"))
+  }
+
   test("check invokeAs on base class") {
     assertResult("method1")(invokeAs[String](obj1, "method1"))
     assertResult("method2")(invokeAs[String](obj1, "method2"))
@@ -103,3 +112,7 @@ object ObjectA {
   def method5(): String = "method5"
   private def method6(): String = "method6"
 }
+
+object FailingInit {
+  throw new IllegalStateException("static init failed")
+}