Unescapes an XML string by replacing the entity references shown below with their equivalent characters as defined by the XML specification - Java XML

Java examples for XML:XML String Escape

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Description

Unescapes an XML string by replacing the entity references shown below with their equivalent characters as defined by the XML specification

Demo Code

public class Main {

  public static void main(String[] argv) {
    String str = "&<java2s.com";
    System.out.println(unencodeXML(str));
  }//from  w  w w . j  a v  a 2s  . c o m

  /**
   * Unescapes an XML string by replacing the entity references shown below with
   * their equivalent characters as defined by the XML specification.
   * <p>
   *
   * <table>
   * <tr>
   * <td>Character</td>
   * <td>Entity Reference</td>
   * </tr>
   * <tr>
   * <td>&lt;</td>
   * <td>&amp;lt;</td>
   * </tr>
   * <tr>
   * <td>&gt;</td>
   * <td>&amp;gt;</td>
   * </tr>
   * <tr>
   * <td>&amp;</td>
   * <td>&amp;amp;</td>
   * </tr>
   * <tr>
   * <td>&apos;</td>
   * <td>&amp;apos;</td>
   * </tr>
   * <tr>
   * <td>&quot;</td>
   * <td>&amp;quot;</td>
   * </tr>
   * </table>
   *
   * @param str
   *          The source string
   * @return The escaped string
   */
  public static String unencodeXML(String str) {
    if (str == null)
      return null;

    StringBuilder b = new StringBuilder();

    int c = 0;
    while (c < str.length()) {
      if (str.charAt(c) == '&') {
        String entity = _entity(str, c);
        if (entity == null)
          b.append('&');
        else {
          if (entity.equals("lt"))
            b.append('<');
          else if (entity.equals("gt"))
            b.append('>');
          else if (entity.equals("amp"))
            b.append('&');
          else if (entity.equals("apos"))
            b.append("'");
          else if (entity.equals("quot"))
            b.append('"');
          else {
            b.append("&");
            b.append(entity);
            b.append(";");
          }

          c += entity.length() + 1;
        }
      } else
        b.append(str.charAt(c));

      c++;
    }

    return b.toString();
  }

  private static String _entity(String src, int ch) {
    int c = ch + 1;

    while (c < src.length()) {
      if (src.charAt(c) == '&')
        return null;
      if (src.charAt(c) == ';')
        return src.substring(ch + 1, c);
      c++;
    }

    return null;
  }

}

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