code: private static Object invoke(Class target, Object o, String methodName, Object[] paras)
  			throws IllegalAccessException, IllegalArgumentException, InvocationTargetException
  	{
  
  		ObjectInfo info = getObjectInfo(target);
  		Class[] parameterType = new Class[paras.length];
  		int i = 0;
  		for (Object para : paras)
  		{
  			parameterType[i++] = para == null ? null : para.getClass();
  		}
  		ObjectMethodMatchConf mf = findMethod(target, methodName, parameterType);
  		if (mf == null)
  		{
  			throw new BeetlParserException(BeetlParserException.NATIVE_CALL_INVALID, "根据参数未找到匹配的方法"+methodName+BeetlUtil.getParameterDescription(parameterType));
  		}
  		Object result = invoke(o, mf, paras);
  		return result;
  
  	}
docs: Beetl 本地方法调用即调用此类，需要考虑到多态。beetl自动调用第一个匹配到的函数，而不会像java那样，调用最合适的匹配到的函数
  @param o 对象实例
  @param methodName 方法名
  @param paras 方法参数
  @return
  @throws IllegalAccessException
  @throws IllegalArgumentException
  @throws InvocationTargetException