SuspiciousInvocationHandlerImplementation

Reports implementations of InvocationHandler that do not proxy standard Object methods like hashCode(), equals(), and toString().

Failing to handle these methods might cause unexpected problems upon calling them on a proxy instance.

Example:

InvocationHandler myHandler = (proxy, method, params) -> {
    System.out.println("Hello World!");
    return null;
  };
  Runnable myProxy = (Runnable) Proxy.newProxyInstance(
    Thread.currentThread().getContextClassLoader(),
    new Class[] {Runnable.class}, myHandler
  );

This code snippet is designed to only proxy the Runnable.run() method. However, calls to any Object methods, like hashCode(), are proxied as well. This can lead to problems like a NullPointerException, for example, when adding myProxy to a HashSet.

New in 2020.2