Suspicious 'InvocationHandler' implementation

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

Inspection Details
Available in:	IntelliJ IDEA 2023.3, Qodana for JVM 2023.3
Plugin:	Java, 233.SNAPSHOT

Last modified: 13 July 2023