org.mvel2.optimizers.impl.refl.nodes.ArrayAccessor Maven / Gradle / Ivy

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/**
 * MVEL (The MVFLEX Expression Language)
 *
 * Copyright (C) 2007 Christopher Brock, MVFLEX/Valhalla Project and the Codehaus
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package org.mvel2.optimizers.impl.refl.nodes;

import java.lang.reflect.Array;

import org.mvel2.compiler.AccessorNode;
import org.mvel2.integration.VariableResolverFactory;

public class ArrayAccessor implements AccessorNode {

    private AccessorNode nextNode;
    private int index;

    public ArrayAccessor() {
    }

    public ArrayAccessor(int index) {
        this.index = index;
    }

    public Object getValue(Object ctx, Object elCtx, VariableResolverFactory vars) {
        if (nextNode != null) {
            return nextNode.getValue(Array.get(ctx, index), elCtx, vars);
        } else {
            try {
                return Array.get(ctx, index);
            } catch (IllegalArgumentException e) {
                // This isn't great, but the mechanism for deoptimizing a stale accessor is currently based on 
                //  Accessor's  throwing a ClassCastException.  Catching  IllegalArgumentException in 
                // org.mvel2.ast.ASTNode.getReducedValueAccelerated(Object, Object, VariableResolverFactory)
                // is a bad idea and currently there is nowhere to easily introduce pre-emptive accessor validity.
                throw new ClassCastException("Argument of type '" + ctx.getClass() + "' is not an Array");
            }
        }
    }

    public Object setValue(Object ctx, Object elCtx, VariableResolverFactory variableFactory, Object value) {
        if (nextNode != null) {
            return nextNode.setValue(Array.get(ctx, index), elCtx, variableFactory, value);
        } else {
            Array.set(ctx, index, value);
            return value;
        }
    }

    public int getIndex() {
        return index;
    }

    public void setIndex(int index) {
        this.index = index;
    }

    public AccessorNode getNextNode() {
        return nextNode;
    }

    public AccessorNode setNextNode(AccessorNode nextNode) {
        return this.nextNode = nextNode;
    }

    public Class getKnownEgressType() {
        return Object[].class;
    }

    public String toString() {
        return "Array Accessor -> [" + index + "]";
    }
}