Java占位符替换工具类

import java.util.HashMap;
    import java.util.Map;  

    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;  

    /**
     * 配置文件或模板中的占位符替换工具类
     * Date: 15-5-8
     * Time: 下午4:12
     */
    public class PlaceholderUtils {  

        private static final Logger logger = LoggerFactory.getLogger(PlaceholderUtils.class);  

        /**
         * Prefix for system property placeholders: "${"
         */
        public static final String PLACEHOLDER_PREFIX = "${";
        /**
         * Suffix for system property placeholders: "}"
         */
        public static final String PLACEHOLDER_SUFFIX = "}";  

        public static String resolvePlaceholders(String text, Map<String, String> parameter) {
            if (parameter == null || parameter.isEmpty()) {
                return text;
            }
            StringBuffer buf = new StringBuffer(text);
            int startIndex = buf.indexOf(PLACEHOLDER_PREFIX);
            while (startIndex != -1) {
                int endIndex = buf.indexOf(PLACEHOLDER_SUFFIX, startIndex + PLACEHOLDER_PREFIX.length());
                if (endIndex != -1) {
                    String placeholder = buf.substring(startIndex + PLACEHOLDER_PREFIX.length(), endIndex);
                    int nextIndex = endIndex + PLACEHOLDER_SUFFIX.length();
                    try {
                        String propVal = parameter.get(placeholder);
                        if (propVal != null) {
                            buf.replace(startIndex, endIndex + PLACEHOLDER_SUFFIX.length(), propVal);
                            nextIndex = startIndex + propVal.length();
                        } else {
                            logger.warn("Could not resolve placeholder '" + placeholder + "' in [" + text + "] ");
                        }
                    } catch (Exception ex) {
                        logger.warn("Could not resolve placeholder '" + placeholder + "' in [" + text + "]: " + ex);
                    }
                    startIndex = buf.indexOf(PLACEHOLDER_PREFIX, nextIndex);
                } else {
                    startIndex = -1;
                }
            }
            return buf.toString();
        }  

        public static void main(String[] args) {
            String aa= "我们都是好孩子,${num}说是嘛？ 我觉得${people}是傻蛋!";
            Map<String, String> map = new HashMap<String, String>();
            map.put("num","小二比");
            map.put("people","小明");
            System.out.println(PlaceholderUtils.resolvePlaceholders(aa, map));
        }  

    }