[JXPATH-129] MethodLookupUtils#matchType uses TypeUtils#canConvert which causes "Ambiguous method call" exception.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Cannot Reproduce
• Fix Version/s: 1.4

Environment

Not relevant.

• Assignee: Unassigned
• Reporter: Robert Ross
• Created: 26/Feb/09 21:57
• Updated: 01/Mar/10 20:27
• Resolved: 28/Feb/10 16:59

Description

MethodLookupUtils#matchParameterTypes calls MethodUtils#matchType.

MethodLookupUtils#matchType includes this:

if (TypeUtils.canConvert(object, expected))

{ return APPROXIMATE_MATCH; }

This goes through a whole process of attempting to convert types using JXPath-specific conversion routines. However, this is not valid logic when attempting to find matching Methods since overloaded functions with "convertable" parameters would still have different function signatures.

An example:

abstract class ExampleClass
{
static final String formatISO(Calendar calendar)

{ return ""};
static final String formatISO(Date date) { return ""}

;
}

If referenced from JXPath with "ExampleClass.formatISO(pathToDateObject)", these two functions would trigger JXPathException("lookupMethod() Ambiguous method call: " + name) because apparently TypeUtils is able to convert a Calendar to a Date and vice-versa.

When attempting to retrieve a function via signature, is it not irrelevant whether JXPath is able to convert a parameter's type or not? Is there a way to change this behavior or provide a way to toggle this behavior similar to the setLenient() method.

Also, the word "Ambiguous" is spelled incorrectly as "Ambigous" three times in MethodLookupUtils.