code: public static Object getObjectValue(Object target,String propertyName){
  		try {
  			PropertyDescriptor descriptor = new PropertyDescriptor(propertyName, target.getClass());
  			return descriptor.getReadMethod().invoke(target);
  		} catch (Exception e) {
  			throw new RuntimeException(e);
  		}
  		
  	}
docs: 获取指定某个对象指定属性的值
  @param target
  @param propertyName
  @throws SecurityException
  @throws NoSuchFieldException