Java 服务器保存不了session

一般是前后端分离 跨域了

拦截器添加代码

 response.setHeader("Access-Control-Allow-Credentials","true");

@Component
public class ComInterceptor extends HandlerInterceptorAdapter {
    @Autowired
    IUserDao userDao;
    @Autowired
    IMethodDao methodDao;
    // 请求之前调用(Controller 方法之前调用)
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
　　　　 response.setHeader("Access-Control-Allow-Credentials","true");
        HttpSession session = request.getSession();
        User user = (User) session.getAttribute("USER");
        JudgeCast.cast(user, ResponseCode.NOT_LOGIN);
        Site siteInfo = userDao.findSiteByUserId(user.getId());
        Cache.methods = methodDao.findMethodBySiteId(siteInfo.getId());
        System.out.println(Cache.methods);
        return true;
    }
}

或者添加配置类

@Configuration
public class CorsConfig {
    @Bean
    public CorsFilter corsFilter() {
        final UrlBasedCorsConfigurationSource urlBasedCorsConfigurationSource = new UrlBasedCorsConfigurationSource();
        final CorsConfiguration corsConfiguration = new CorsConfiguration();
        /*是否允许请求带有验证信息*/
        corsConfiguration.setAllowCredentials(true);
        /*允许访问的客户端域名*/
        corsConfiguration.addAllowedOrigin("*");
        /*允许服务端访问的客户端请求头*/
        corsConfiguration.addAllowedHeader("*");
        /*允许访问的方法名,GET POST等*/
        corsConfiguration.addAllowedMethod("*");
        urlBasedCorsConfigurationSource.registerCorsConfiguration("/**", corsConfiguration);
        return new CorsFilter(urlBasedCorsConfigurationSource);
    }
}