dev.haeusler.mojo.PropertyResolver Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jasypt-maven-plugin Show documentation
Properties Maven Plugin with Jasypt support
There is a newer version: 1.2
package dev.haeusler.mojo;

/*
 * 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.
 */

import java.util.Properties;

class PropertyResolver {

    /**
     * Retrieves a property value, replacing values like ${token} using the Properties to look them up. Shamelessly
     * adapted from:
     * http://maven.apache.org/plugins/maven-war-plugin/xref/org/apache/maven/plugin/war/PropertyUtils.html It will
     * leave unresolved properties alone, trying for System properties, and environment variables and implements
     * reparsing (in the case that the value of a property contains a key), and will not loop endlessly on a pair like
     * test = ${test}
     *
     * @param key         property key
     * @param properties  project properties
     * @param environment environment variables
     * @return resolved property value
     * @throws IllegalArgumentException when properties are circularly defined
     */
    public String getPropertyValue(String key, Properties properties, Properties environment) {
        String value = properties.getProperty(key);

        ExpansionBuffer buffer = new ExpansionBuffer(value);

        CircularDefinitionPreventer circularDefinitionPreventer =
                new CircularDefinitionPreventer().visited(key, value);

        while (buffer.hasMoreLegalPlaceholders()) {
            String newKey = buffer.extractPropertyKey();
            String newValue = fromPropertiesThenSystemThenEnvironment(newKey, properties, environment);

            circularDefinitionPreventer.visited(newKey, newValue);

            buffer.add(newKey, newValue);
        }

        return buffer.toString();
    }

    private String fromPropertiesThenSystemThenEnvironment(String key, Properties properties, Properties environment) {
        String value = properties.getProperty(key);

        // try global environment
        if (value == null) {
            value = System.getProperty(key);
        }

        // try environment variable
        if (value == null && key.startsWith("env.") && environment != null) {
            value = environment.getProperty(key.substring(4));
        }

        return value;
    }
}