@Mock
    private RestTemplate restTemplate;

         /**
         *  以 exchange 为例 ，restTemplate 其余方法也一样，给对参数类型就可以了
         */
        Mockito.when(restTemplate.exchange(Mockito.any(String.class), Mockito.any(HttpMethod.class), Mockito.any(HttpEntity.class),Mockito.any(Class.class))).thenReturn(Mockito.any());