GenericTokenParser.java

package com.founderdpt.comm.xworld.plugin.struts2.util;

public class GenericTokenParser {

  private final String openToken;
  private final String closeToken;
  private final TokenHandler handler;

  public GenericTokenParser(String openToken, String closeToken, TokenHandler handler) {
    this.openToken = openToken;
    this.closeToken = closeToken;
    this.handler = handler;
  }

  public String parse(String text) {
    StringBuilder builder = new StringBuilder();
    if (text != null) {
      String after = text;
      int start = after.indexOf(openToken);
      int end = after.indexOf(closeToken);
      while (start > -1) {
        if (end > start) {
          String before = after.substring(0, start);
          String content = after.substring(start + openToken.length(), end);
          String substitution = handler.handleToken(content);
          builder.append(before);
          builder.append(substitution);
          after = after.substring(end + closeToken.length());
        } else if (end > -1) {
          String before = after.substring(0, end);
          builder.append(before);
          builder.append(closeToken);
          after = after.substring(end + closeToken.length());
        } else {
          break;
        }
        start = after.indexOf(openToken);
        end = after.indexOf(closeToken);
      }
      builder.append(after);
    }
    return builder.toString();
  }

}