[VELOCITY-924] Bad cache handling for java.lang.Class methods

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.2
• Fix Version/s: 2.2
• Component/s: Engine
• Labels: regression
• Assignee: Claude Brisson
• Reporter: Thomas Mortagne
• Created: 03/Jan/20 11:29
• Updated: 09/Jan/20 14:22
• Resolved: 07/Jan/20 09:54

Description

Requirement:

A binding $var containing an object which class (org.xwiki.MyClass) implementing a String getName() method.

The following code:

$var.class.getName()
$var.getName()

fail with:

Caused by: org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getName' in  class org.xwiki.MyClass threw exception java.lang.IllegalArgumentException: object is not an instance of declaring class at mytemplaye[line 1, column 26]
	at org.apache.velocity.runtime.parser.node.ASTMethod.handleInvocationException(ASTMethod.java:306)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:239)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:369)
	at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:490)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:423)
	at org.apache.velocity.Template.merge(Template.java:358)
	at org.apache.velocity.Template.merge(Template.java:262)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:271)
	... 69 more
Caused by: java.lang.IllegalArgumentException: object is not an instance of declaring class
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:565)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:548)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:219)
	... 75 more

The reason is that ClassUtils.getMethod cache does not make any difference between an instance of Class<org.xwiki.MyClass> and and instance of org.xwiki.MyClass so when ASTMethod#execute ask for the second getName() it end up with Class#getName() instead of MyClass#getName().

Was working fine in 1.7.