算法核心思想：父类封装算法逻辑，子类填充具体算法

下面以sevlet规范来说明一下： 首先抽象一个http的请求对象：

public class HttpRequest {    public String header;    public String body;}public abstract  class HttpSevlet {    public abstract  void doPost(HttpRequest request);    public abstract  void doGet(HttpRequest request);        public void doService(HttpRequest request){        if(request.header.equals("post")){            doPost(request);        }        if(request.header.equals("get")){            doGet(request);        }    }}//各个子类实现自己具体的逻辑：public class LoginServlet extends HttpSevlet {    public void doPost(HttpRequest request) {    }    public void doGet(HttpRequest request) {    }}

与泛型结合使用模板方法

逻辑：设计一个抽象类,把通过interface（http、thrift、dubbo）请求的数据缓存在EhCache中，如果缓存中的数据过期或者被LRU算法淘汰，重新通过interface获取，再次缓存起来.

public abstract class EhcacheBase
    
      {    private static final Log LOG = LogFactory.getLog(EhcacheBase.class);    private Cache cache;    private long dataVersion=System.currentTimeMillis();    public EhcacheBase(Cache cache) {        this.cache=cache;    }    public abstract T getValueFromInterface(String key);    public abstract Map
     
       getBatchValueFromInterface(List
      
        keys);    public T getValue(String key){        return getValue(key,true);    }    public T getValueFromInterfaceAndResetCache(String key){        T newsDetailResult = getValueFromInterface(key);        if(null!=newsDetailResult){            try{                cache.put( new Element(key,newsDetailResult) );                dataVersion=System.currentTimeMillis();            }catch(Exception ex){                LOG.error("key="+key,ex);            }        }        return newsDetailResult;    }    public Map
       
         getBatchValueFromInterfaceAndResetCache(List
        
          keyList){        Map
         
           newsDetailMap = getBatchValueFromInterface(keyList); newsDetailMap.forEach((nid,newsDetail) -> { if(newsDetail != null){ try{ cache.put( new Element(nid,newsDetail) ); dataVersion=System.currentTimeMillis(); }catch(Exception ex){ LOG.error("nid="+nid,ex); } } }); return newsDetailMap; } /** * 父类在此处实现算法逻辑 !!! **/ public T getValue(String key,boolean cacheFirst){ if (null==key) return null; if(cacheFirst){ Element element = cache.get(key); if( null!=element && null!=element.getObjectValue() ) return (T)element.getObjectValue(); else{ return getValueFromInterfaceAndResetCache(key); } }else{ return getValueFromInterfaceAndResetCache(key); } } public T getValueFromCache(String key) { if (null==key) { return null; } Element element=cache.get(key); if(null != element && null != element.getObjectValue()) return (T) element.getObjectValue(); else{ return null; } } public long getDataVersion() { return dataVersion; }}