使用pageHelper分页插件出错解决不了

空指针异常，你没看到吗？pi对象在哪使用的

代码截图一下 有助于找错

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration(locations = { "classpath:applicationContext.xml",
		"file:src/main/webapp/WEB-INF/dispatcherServlet-servlet.xml" })
public class MvcTest {
	// 传入Springmvc的ioc
	@Autowired
	WebApplicationContext context;
	// 虚拟mvc请求，获取到处理结果。
	MockMvc mockMvc;

	@Before
	public void initMokcMvc() {
		mockMvc = MockMvcBuilders.webAppContextSetup(context).build();
	}

	@Test
	public void testPage() throws Exception {
		//模拟请求拿到返回值
		MvcResult result = mockMvc.perform(MockMvcRequestBuilders.get("/stds").param("pn", "5"))
				.andReturn();
		
		//请求成功以后，请求域中会有pageInfo；我们可以取出pageInfo进行验证
		MockHttpServletRequest request = result.getRequest();
		PageInfo pi = (PageInfo) request.getAttribute("pageInfo");
		System.out.println("当前页码："+pi.getPageNum());
		System.out.println("总页码："+pi.getPages());
		System.out.println("总记录数："+pi.getTotal());
		System.out.println("在页面需要连续显示的页码");
		int[] nums = pi.getNavigatepageNums();
		for (int i : nums) {
			System.out.print(" "+i);
		}
		
		//获取员工数据
		List<Student> list = pi.getList();
		for (Student student : list) {
			System.out.println("ID："+student.getId()+"==>Name:"+student.getName());
		}
		
	}

}