@Test
public void preHandle_当设置token的username_那么username可以在线程中拿出来用() throws Exception {

    UserInterceptor userInterceptor = new UserInterceptor();
    MockHttpServletRequest request = new MockHttpServletRequest();
    request.addHeader("x-client-token-user", "{\"user_name\":\"zhangsan\"}");
    MockHttpServletResponse response = new MockHttpServletResponse();
    userInterceptor.preHandle(request, response, new Object());
    Assert.assertEquals(UserContextHolder.getInstance().getUsername(), "zhangsan");
}