com.google.code.configprocessor.maven.MavenExpressionResolver.java Source code

Introduction

Here is the source code for com.google.code.configprocessor.maven.MavenExpressionResolver.java

Source

/*
 * Copyright (C) 2009 Leandro de Oliveira Aparecido <lehphyro@gmail.com>
 *
 * 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 com.google.code.configprocessor.maven;

import org.apache.commons.lang.*;
import org.codehaus.plexus.component.configurator.expression.*;

import com.google.code.configprocessor.expression.*;
import com.google.code.configprocessor.util.*;

/**
 * Resolver of placeholders.
 * 
 * @author Leandro Aparecido
 * @see org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator
 */
public class MavenExpressionResolver implements ExpressionResolver {

    /**
     * True if placeholders must be replaced.
     */
    private boolean replacePlaceholders;

    /**
     * Evaluator of expressions to use.
     */
    private ExpressionEvaluator evaluator;

    public MavenExpressionResolver(ExpressionEvaluator evaluator) {
        this(evaluator, true);
    }

    public MavenExpressionResolver(ExpressionEvaluator evaluator, boolean replacePlaceholders) {
        this.evaluator = evaluator;
        this.replacePlaceholders = replacePlaceholders;
    }

    /**
     * Resolves the given text replacing any placeholders if necessary.
     * 
     * @param value Value to resolve.
     * @param isPropertiesValue True is the value will be used in .properties files and should be escaped.
     * @return Resolved value with values replaced as necessary.
     */
    public String resolve(String value, boolean isPropertiesValue) {
        String resolvedValue;

        if (replacePlaceholders) {
            try {
                Object aux = evaluator.evaluate(value);
                if ((aux != null) && !(aux instanceof String)) {
                    throw new IllegalArgumentException("Expression [" + value + "] did not resolve to String");
                }
                resolvedValue = (String) aux;

                if (isPropertiesValue && !StringUtils.equals(value, resolvedValue)) {
                    resolvedValue = PropertiesUtils.escapePropertyValue(resolvedValue);
                }
            } catch (ExpressionEvaluationException e) {
                throw new RuntimeException("Error resolving expression [" + value + "]", e);
            }
        } else {
            resolvedValue = value;
        }

        return resolvedValue;
    }

}