~~~ /** * Copyright 2009-2019 the original author or authors. * * 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. */ package org.apache.ibatis.parsing; /** * @author Clinton Begin */ 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) { if (text == null || text.isEmpty()) { return ""; } // search open token int start = text.indexOf(openToken); if (start == -1) { return text; } char[] src = text.toCharArray(); int offset = 0; final StringBuilder builder = new StringBuilder(); StringBuilder expression = null; while (start > -1) { if (start > 0 && src[start - 1] == '\\') { // this open token is escaped. remove the backslash and continue. builder.append(src, offset, start - offset - 1).append(openToken); offset = start + openToken.length(); } else { // found open token. let's search close token. if (expression == null) { expression = new StringBuilder(); } else { expression.setLength(0); } builder.append(src, offset, start - offset); offset = start + openToken.length(); int end = text.indexOf(closeToken, offset); while (end > -1) { if (end > offset && src[end - 1] == '\\') { // this close token is escaped. remove the backslash and continue. expression.append(src, offset, end - offset - 1).append(closeToken); offset = end + closeToken.length(); end = text.indexOf(closeToken, offset); } else { expression.append(src, offset, end - offset); break; } } if (end == -1) { // close token was not found. builder.append(src, start, src.length - start); offset = src.length; } else { builder.append(handler.handleToken(expression.toString())); offset = end + closeToken.length(); } } start = text.indexOf(openToken, offset); } if (offset < src.length) { builder.append(src, offset, src.length - offset); } return builder.toString(); } } ~~~