MVEL表达式：java.lang.ClassCastException：[B不能转换为java.lang.Object

Question

I am writing few MVEL expression "$input.get('RESULT').array()[1]" where $input.get('RESULT') return a ByteBuffer , so I am converting it into array using array() and then trying to get value of index 1. where array have 16 attribute.

But when Mvel executing this expression I am getting

 java.lang.ClassCastException: [B cannot be cast to java.lang.Object

I am using below code

MVEL.executeExpression(statement, fieldContext.getContext(), fieldContext.getVariables());

I have written other expression as well which is working fine, I am getting this error for Byte one.

Any help here will be appreciated.

Update : When I use ByteBuffer get method I got below error so I thought to give a try with array .

java.lang.IllegalAccessError: tried to access class java.nio.HeapByteBuffer from class ASMAccessorImpl_2330495751530608772190
    at ASMAccessorImpl_2330495751530608772190.getValue(Unknown Source)
    at org.mvel2.optimizers.dynamic.DynamicGetAccessor.getValue(DynamicGetAccessor.java:79)
    at org.mvel2.ast.ASTNode.getReducedValueAccelerated(ASTNode.java:108)
    at org.mvel2.MVELRuntime.execute(MVELRuntime.java:86)
    at org.mvel2.compiler.CompiledExpression.getDirectValue(CompiledExpression.java:123)
    at org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:119)
    at org.mvel2.MVEL.executeExpression(MVEL.java:922)`

Answer 1

You don't have to convert to byte[] with array() , it should be enough to

$input.get('RESULT').get(1)

as per ByteBuffer.get() method docs:

public abstract byte get​(int index)

Absolute get method. Reads the byte at the given index.