ClassPath.getClassFile() and friends do not work with JDK 9 and higher

When trying to get the class file for Java classes (ie. java.lang.String), an IOException is thrown:

Exception in thread "main" java.io.IOException: Couldn't find: java.lang.String.class
at org.apache.bcel.util.ClassPath.getClassFile(ClassPath.java:279)
at org.apache.bcel.util.ClassPath.getClassFile(ClassPath.java:301)
at bcel.test.GetClassFileTest.main(GetClassFileTest.java:12)

 

The root cause appears to be the restructuring of Java starting with Java 9. Specifically, the removal of the rt.jar. The above excpetion can be reproduced using a simple application:

package bcel.test;

import java.io.IOException;

import org.apache.bcel.util.ClassPath;

public class GetClassFileTest {

   public static void main(String[] args) throws IOException {
      String className = "java.lang.String";
      System.out.println("Looking up ClassPath.ClassFile for: " + className);
      ClassPath.ClassFile classFile = ClassPath.SYSTEM_CLASS_PATH.getClassFile(className);
      if (classFile != null)

{          System.out.println("Class file base: " + classFile.getBase());          System.out.println("Class file path: " + classFile.getPath());       }

   }

}

 

Running this on Java 8 produces the following output, whereas running it on Java 9+ produces the IOException:

Class file base: C:\jdk1.8.0_161\jre\lib\rt.jar
Class file path: java/lang/String.class