JSONLiteral.java

/*
 * Copyright © 2011 Jason J.A. Stephenson
 * 
 * This file is part of sigio.jar.
 * 
 * sigio.jar is free software: you can redistribute it and/or modify it
 * under the terms of the Lesser GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * sigio.jar is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * Lesser GNU General Public License for more details.
 * 
 * You should have received a copy of the Lesser GNU General Public License
 * along with sigio.jar.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.sigio.json;

import java.util.ResourceBundle;

/**
 * Enum for the allowed JSON literals as defined in RFC4627.
 */
public enum JSONLiteral {
  /**
   * The null literal string.
   */
  NULL("null"),
  /**
   * The true literal string. Our implementation returns this
   * instead of Boolean.TRUE.
   */
  TRUE("true"),
  /**
   * The false literal string. Our implementation returns this
   * instead of Boolean.FALSE.
   */
  FALSE("false");

  private final String literalValue;

  /**
   * Our hidden constructor.
   */
  JSONLiteral(String str) {
    this.literalValue = str;
  }

  /**
   * Get our literal value.
   *
   * @return string with the literal JSON value
   */
  public String value() {
    return this.literalValue;
  }

  /**
   * Returns a string representation of the object.
   *
   * @return String of the literal JSON value
   */
  @Override
  public String toString() {
    return this.literalValue;
  }

  /**
   * Check if a passed in string matches the literal's value.
   *
   * @param str string to check
   * @return <code>true</code> if the string matches,
   * <code>false</code> if not
   */
  public boolean equals(String str) {
    if (str.equals(this.literalValue))
      return true;
    return false;
  }

  /**
   * Get a JSONLiteral from a string.
   *
   * @param str string containing a JSON literal value
   * @return the JSONLiteral whose value matches the string
   * @throws JSONException if the string does not match a JSON
   * literal value
   */
  public static JSONLiteral fromString(String str) throws JSONException {
    for (JSONLiteral l : JSONLiteral.values()) {
      if (l.equals(str))
        return l;
    }
    ResourceBundle bundle = com.sigio.json.BundleLoader.getBundle();
    throw new JSONException(String.format(bundle.getString("INVALID_LITERAL"), str));
  }

}