ArrayIndexOutOfBoundsException in MethodBasedEvaluationContext [SPR-14554]

[spring-projects-issues]

Matthias Rühl opened SPR-14554 and commented

java.lang.ArrayIndexOutOfBoundsException: 2
at org.springframework.context.expression.MethodBasedEvaluationContext.lazyLoadArguments(MethodBasedEvaluationContext.java:94)
at org.springframework.context.expression.MethodBasedEvaluationContext.lookupVariable(MethodBasedEvaluationContext.java:68)
at org.springframework.cache.interceptor.CacheEvaluationContext.lookupVariable(CacheEvaluationContext.java:74)
at org.springframework.expression.spel.ExpressionState.lookupVariable(ExpressionState.java:144)
at org.springframework.expression.spel.ast.VariableReference.getValueInternal(VariableReference.java:75)
at org.springframework.expression.spel.ast.MethodReference.getArguments(MethodReference.java:154)
at org.springframework.expression.spel.ast.MethodReference.getValueInternal(MethodReference.java:84)
at org.springframework.expression.spel.ast.CompoundExpression.getValueRef(CompoundExpression.java:57)
at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:87)
at org.springframework.expression.spel.ast.SpelNodeImpl.getValue(SpelNodeImpl.java:120)
at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:242)
at org.springframework.cache.interceptor.CacheOperationExpressionEvaluator.key(CacheOperationExpressionEvaluator.java:117)
at org.springframework.cache.interceptor.CacheAspectSupport$CacheOperationContext.generateKey(CacheAspectSupport.java:738)
at org.springframework.cache.interceptor.CacheAspectSupport.generateKey(CacheAspectSupport.java:554)
at org.springframework.cache.interceptor.CacheAspectSupport.findCachedItem(CacheAspectSupport.java:498)
at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:389)
at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:327)
at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:61)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)

This is my cacheable annotation:

@Cacheable(value = "dummyCache", key = "'getSomethingList_'.concat(#var1).concat(T(java.util.Arrays).deepHashCode(#var2))")
List<Something> getSomethingList(String var1, Integer... var2);

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Affects: 4.2.7, 4.3.2

Issue Links:

• MethodBasedEvaluationContext.lazyLoadArguments() execution fails for empty variable arguments call [SPR-14453] #19022 MethodBasedEvaluationContext.lazyLoadArguments() execution fails for empty variable arguments call

Referenced from: commits 4543a28, 48980a2, fae503d

Backported to: 4.2.8

[spring-projects-issues]

Stéphane Nicoll commented

Is that exception thrown for every call or with a specific set of arguments? If so provide them, a sample would be better to reduce the amount of time to spend to reproduce the issue.

Also, I would strongly recommend you to use a KeyGenerator for this via the keyGenerator argument on the annotation. This bug isn't critical, you have an easy way out that is better IMO than your current code.

[spring-projects-issues]

Matthias Rühl commented

With the following arguments the error occurs:
var1 = "A"
var2 = [10,20,30]

Sounds good, I will take a look at the KeyGenerator feature :)

[spring-projects-issues]

Juergen Hoeller commented

It seems that this is a side effect of the change made for #19022 in 4.3.2: While args may be shorter than parameterNames in an empty-vararg scenario there, it may also be longer in a multi-vararg scenario... So this seems like a regression in 4.3.2, fixing an index-out-of-bounds in one scenario at the expense of causing it in the other. In order to address both scenarios, some more sophisticated treatment will be necessary: possibly loop until parameterNames is at its last element, then explicitly specify null if there is no args entry anymore, pass in the args value as-is if there is exactly one element left, or extract the remaining args entries into a dedicated array and specify that as variable value.

Let's also backport the revised algorithm to 4.2.8, addressing both scenarios there as well.

[spring-projects-issues]

Juergen Hoeller commented

Since I've been researching our general varargs handling in SpEL a bit, I guess I should take this issue right away...

The existing MethodBasedEvaluationContextTests do not expose varargs the SpEL way (i.e. in a flattened array), which is why they are not leading to the index-out-of-bounds.