[SPARK-45874] Remove Java version check from `IsolatedClientLoader`

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 4.0.0
• Fix Version/s: 4.0.0
• Component/s: SQL
• Labels: pull-request-available
• Assignee: Yang Jie
• Reporter: Yang Jie
• Created: 10/Nov/23 06:41
• Updated: 13/Nov/23 05:53
• Resolved: 12/Nov/23 22:43

Description

val rootClassLoader: ClassLoader =
  if (SystemUtils.isJavaVersionAtLeast(JavaVersion.JAVA_9)) {
    // In Java 9, the boot classloader can see few JDK classes. The intended parent
    // classloader for delegation is now the platform classloader.
    // See http://java9.wtf/class-loading/
    val platformCL =
    classOf[ClassLoader].getMethod("getPlatformClassLoader").
      invoke(null).asInstanceOf[ClassLoader]
    // Check to make sure that the root classloader does not know about Hive.
    assert(Try(platformCL.loadClass("org.apache.hadoop.hive.conf.HiveConf")).isFailure)
    platformCL
  } else {
    // The boot classloader is represented by null (the instance itself isn't accessible)
    // and before Java 9 can see all JDK classes
    null
  } 

Spark 4.0.0 has a minimum requirement of Java 17, so the version check for Java 9 is not necessary.

Issue Links

• links to: GitHub Pull Request #43747