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));  
        }  
      
    }