用token的方式动态的解析替换特殊值,举个小例子挺不错。
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 && text.length() > 0) { char[] src = text.toCharArray(); int offset = 0; int start = text.indexOf(openToken, offset); while (start > -1) { if (start > 0 && src[start - 1] == '\\') { // the variable is escaped. remove the backslash. builder.append(src, offset, start - 1).append(openToken); offset = start + openToken.length(); } else { int end = text.indexOf(closeToken, start); if (end == -1) { builder.append(src, offset, src.length - offset); offset = src.length; } else { builder.append(src, offset, start - offset); offset = start + openToken.length(); String content = new String(src, offset, end - offset); builder.append(handler.handleToken(content)); offset = end + closeToken.length(); } } start = text.indexOf(openToken, offset); } if (offset < src.length) { builder.append(src, offset, src.length - offset); } } return builder.toString(); } }