com.orientechnologies.common.parser.OSystemVariableResolver Maven / Gradle / Ivy

/*
  *
  *  *  Copyright 2014 Orient Technologies LTD (info(at)orientechnologies.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.
  *  *
  *  * For more information: http://www.orientechnologies.com
  *
  */
package com.orientechnologies.common.parser;

/**
 * Resolve system variables embedded in a String.
 * 
 * @author Luca Garulli (luca.garulli--at--assetdata.it)
 * 
 */
public class OSystemVariableResolver implements OVariableParserListener {
  public static final String             VAR_BEGIN = "${";
  public static final String             VAR_END   = "}";

  private static OSystemVariableResolver instance  = new OSystemVariableResolver();

  public static String resolveSystemVariables(final String iPath) {
    return resolveSystemVariables(iPath, null);
  }

  public static String resolveSystemVariables(final String iPath, final String iDefault) {
    if (iPath == null)
      return iDefault;

    return (String) OVariableParser.resolveVariables(iPath, VAR_BEGIN, VAR_END, instance, iDefault);
  }

  public static String resolveVariable(final String variable) {
    if( variable == null )
      return null;

    String resolved = System.getProperty(variable);

    if (resolved == null)
      // TRY TO FIND THE VARIABLE BETWEEN SYSTEM'S ENVIRONMENT PROPERTIES
      resolved = System.getenv(variable);

    return resolved;
  }

  public String resolve(final String variable) {
    return resolveVariable(variable);
  }
}