NoSuchMethodError: java.nio.ByteBuffer with Java9 Builds

[jordanpadams]

🐛 Describe the bug

Per jetty/jetty.project#3244

Like many other projects (Tomcat, MongoDB, etc.) compiling with JDK 9+ with release 8 produces incorrect bytecode for these ByteBuffer methods:

• position(int)
• limit(int) None
• mark​()
• reset​()
• clear()
• flip()
• rewind​()

Running a Jetty compiled with JDK 9+ with release 8 in a JDK 8 JVM will produce a NoSuchMethodError.

The solution is to cast the ByteBuffer to Buffer when calling those methods:

((Buffer)byteBuffer).position(0);