maven-core/src/main/java/org/apache/maven/configuration/BeanConfigurationValuePreprocessor.java

package org.apache.maven.configuration;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

/**
 * Preprocesses a value from a bean configuration before the bean configurator unmarshals it into a bean property. A
 * common use case for such preprocessing is the evaluation of variables within the configuration value.
 *
 * @author Benjamin Bentmann
 */
public interface BeanConfigurationValuePreprocessor
{

    /**
     * Preprocesses the specified bean configuration value. The optional type provided to this method is a hint (not a
     * requirement) for the preprocessor to resolve the value to a compatible value or a (string) value than can be
     * unmarshalled into that type. The preprocessor is not required to perform any type conversion but should rather
     * filter out incompatible values from its result.
     *
     * @param value The configuration value to preprocess, must not be {@code null}.
     * @param type The target type of the value, may be {@code null}.
     * @return The processed configuration value or {@code null} if none.
     * @throws BeanConfigurationException If an error occurred while preprocessing the value.
     */
    Object preprocessValue( String value, Class<?> type )
        throws BeanConfigurationException;

}