array varargs conversion error in SpEL expression [SPR-11494]

[spring-projects-issues]

Jacek Obarymski opened SPR-11494 and commented

The following test case (see ):

ExpressionParser parser = new SpelExpressionParser();
Expression exp = parser.parseExpression("T(java.util.Arrays).asList('a','b')");
List<String> list = (List<String>) exp.getValue();
assertThat(list.size(), is(2));

throws an exception:

java.lang.IllegalArgumentException: Final expected argument should be array type (the varargs parameter)
	at org.springframework.util.Assert.isTrue(Assert.java:65)
	at org.springframework.expression.spel.support.ReflectionHelper.compareArgumentsVarargs(ReflectionHelper.java:144)
	at org.springframework.expression.spel.support.ReflectiveMethodResolver.resolve(ReflectiveMethodResolver.java:154)
	at org.springframework.expression.spel.ast.MethodReference.findAccessorForMethod(MethodReference.java:189)
	at org.springframework.expression.spel.ast.MethodReference.getValueInternal(MethodReference.java:118)
	at org.springframework.expression.spel.ast.MethodReference.access$100(MethodReference.java:44)
	at org.springframework.expression.spel.ast.MethodReference$MethodValueRef.getValue(MethodReference.java:258)
	at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:84)
	at org.springframework.expression.spel.ast.SpelNodeImpl.getValue(SpelNodeImpl.java:103)
	at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:68)

---

Affects: 4.0.2

[spring-projects-issues]

Stéphane Nicoll commented

Hi,

I have added a repro project with your test and it passes for me. Could you please clarify there the scenario that is failing for you?
https://github.com/spring-projects/spring-framework-issues/tree/master/SPR-11494

Thanks

[spring-projects-issues]

Jacek Obarymski commented

sorry forgot to add:

List<String> list = (List<String>) exp.getValue(); //the exception actually happens here.
assertThat(list.size(), is(2));

[spring-projects-issues]

Juergen Hoeller commented

Fixed through falling back to the raw parameter type in the TypeDescriptor(MethodParameter) constructor, properly detecting the vararg array even in case of an unresolvable type variable, and through restoring getElementTypeDescriptor's original behavior for arrays, i.e. always returning a non-null descriptor.

Juergen