docs: public static MethodInvoker getInvokder(Class c, String name)
  	{
  		//先检测 get，然后 is，然后是general get
  //性能慢，但需要证,重要的是，类重加载后，根据字符串知道method，是错误的
  //		String key = c.toString().concat("_").concat(name); 
  		MethodInvoker invoker = null;
  		Map<String,MethodInvoker> map = methodInvokerCache.get(c);
  		if(map!=null){
  			invoker = map.get(name);
  			if (invoker != null)
  			{
  				return invoker;
  			}
  		}
  		
  		//try get
  		String methodName = getGetMethod(name);
  		Method method = getGetMethod(c, methodName, null);
  		if (method != null)
  		{
  			invoker = new PojoMethodInvoker(method);
  			
  		}
  		
  		//try is 
  		if(invoker==null){			
  			if(name.startsWith("is")){
  				methodName = name;
  				method = getGetMethod(c, methodName, null);
  				if(method!=null){
  					invoker = new PojoMethodInvoker(method);
  				}
  			}else{
  				methodName = getIsMethod(name);
  				method = getGetMethod(c, methodName, null);
  				if(method!=null){
  					invoker = new PojoMethodInvoker(method);
  				}
  			}
  	
  		}
  		
  		//bug fix:java bean 规范  cName--> getcName()
  		if(invoker==null){
  			if(name.length()>1&&(name.charAt(1)>='A'&&name.charAt(1)<='Z')){				
  				methodName = "get"+name;
  				method = getGetMethod(c, methodName, null);
  				if(method!=null){
  					invoker = new PojoMethodInvoker(method);
  				}else{
  					methodName = "is"+name;
  					method = getGetMethod(c, methodName, null);
  					if(method!=null){
  						invoker = new PojoMethodInvoker(method);
  					}
  				}
  				
  			}
  		}
  		
  		// general get,string objct allow
  		if(invoker==null){
  			method = getGetMethod(c, "get", new Class[]
  					{ Object.class });
  			if (method != null)
  			{
  				invoker = new GeneralGetMethodInvoker(method, name);
  			}else{
  				method = getGetMethod(c, "get", new Class[]
  						{ String.class });
  				if(method!=null){
  					invoker = new GeneralGetMethodInvoker(method, name);
  				}
  			}
  			
  		}
  		
  		
  		
  		
  		if (invoker != null)
  		{
  			if(map==null){
  				map = new ConcurrentHashMap<String,MethodInvoker>();
  				methodInvokerCache.put(c, map);
  			}
  			map.put(name, invoker);
  			return invoker;
  		}
  		else
  		{
  			return null;
  		}
  
  	}