[HADOOP-13398] prevent user classes from loading classes in the parent classpath with ApplicationClassLoader

• Type: Sub-task
• Status: Patch Available
• Priority: Critical
• Resolution: Unresolved
• Component/s: util
• Assignee: Sangjin Lee
• Reporter: Sangjin Lee
• Created: 21/Jul/16 19:16
• Updated: 31/Mar/17 17:11

Description

Today, a user class is able to trigger loading a class from Hadoop's dependencies, with or without the use of ApplicationClassLoader, and it creates an implicit dependence from users' code on Hadoop's dependencies, and as a result dependency conflicts.

We should modify ApplicationClassLoader to prevent a user class from loading a class from the parent classpath.

This should also cover resource loading (including ClassLoader.getResources() and as a corollary ServiceLoader).