org.mule.module.spel.ExpressionFactory.java Source code

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Here is the source code for org.mule.module.spel.ExpressionFactory.java

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/*
 * Copyright (c) 2011, Victor Romero. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301  USA
 */
package org.mule.module.spel;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.mule.api.lifecycle.Disposable;
import org.springframework.expression.Expression;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.util.Assert;

public class ExpressionFactory implements Disposable {
    // SpEL parser instances are reusable and thread-safe.
    protected final static ExpressionParser PARSER = new SpelExpressionParser();

    Map<String, Expression> expressions = new ConcurrentHashMap<String, Expression>(4);

    public Expression create(String expression) {
        Assert.hasLength(expression, "Expression cannot be null or empty");

        Expression exp = expressions.get(expression);
        if (exp == null) {
            exp = PARSER.parseExpression(expression);
            expressions.put(expression, exp);
        }

        return exp;
    }

    public void dispose() {
        expressions.clear();
    }
}