org.everit.expression.jexl.JexlExpressionCompiler.java Source code

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Here is the source code for org.everit.expression.jexl.JexlExpressionCompiler.java

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/*
 * Copyright (C) 2011 Everit Kft. (http://www.everit.biz)
 *
 * 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.everit.expression.jexl;

import java.util.Set;

import org.apache.commons.jexl3.JexlBuilder;
import org.apache.commons.jexl3.JexlEngine;
import org.apache.commons.jexl3.JexlInfo;
import org.apache.commons.jexl3.JexlScript;
import org.everit.expression.CompiledExpression;
import org.everit.expression.ExpressionCompiler;
import org.everit.expression.ParserConfiguration;
import org.everit.expression.jexl.internal.CustomizedJexlArithmetic;
import org.everit.expression.jexl.internal.JexlCompiledExpression;

/**
 * Jexl based implementation of {@link ExpressionCompiler}.
 */
public class JexlExpressionCompiler implements ExpressionCompiler {

    @Override
    public CompiledExpression compile(final char[] document, final int expressionStart, final int expressionLength,
            final ParserConfiguration parserConfiguration) {
        return compile(String.valueOf(document, expressionStart, expressionLength), parserConfiguration);
    }

    @Override
    public CompiledExpression compile(final String expression, final ParserConfiguration parserConfiguration) {

        if (parserConfiguration == null) {
            throw new IllegalArgumentException("Parser configuration must be defined");
        }

        JexlInfo jexlInfo = new JexlInfo(parserConfiguration.getName(), parserConfiguration.getStartRow(),
                parserConfiguration.getStartColumn());
        String[] parameterNames = null;
        if (parserConfiguration.getVariableTypes() != null) {
            Set<String> parameterSet = parserConfiguration.getVariableTypes().keySet();
            parameterNames = parameterSet.toArray(new String[parameterSet.size()]);
        }

        JexlEngine jexlEngine = new JexlBuilder().silent(false).debug(true)
                .loader(parserConfiguration.getClassLoader()).arithmetic(new CustomizedJexlArithmetic(true))
                .create();

        JexlScript script = jexlEngine.createScript(jexlInfo, expression, parameterNames);
        return new JexlCompiledExpression(script);
    }
}