假设我们要做一个学校的管理系统，要求不同的角色用户登录进去所看到的内容是不同的，例如校长和门卫登录进去所看到的菜单页面是不同的。校长可以看到全校的摄像头，而门卫看到的摄像头个数则是有限制的。那么如何来实现呢？
首先来分析需要些什么：
1.用户表 user
2.角色表 role
3.菜单表 menu
4.摄像头表 camera
5.用户角色表 roleUser
6.用户菜单表 roleMenu
7.用户摄像头表 roleCamera
以下截图仅供举例参考
user表字段
菜单表字段
菜单表数据库数据
摄像头表字段
摄像头表数据库数据
用户角色关联表
用户菜单关联表
用户摄像头关联表
关于表的数据就是这些了，里面的字段根据自己的项目需求添加。
前台的整个执行流程是什么呢？
点击添加用户
填写资料之后保存
点击保存之后
form表单提交到后台将数据添加到用户表（user）中，这个基本的增删改查不多说了，很简单。
然后写一个角色管理页面，可以配置角色。
角色管理页面
点击 添加角色
添加角色编辑页面
点击保存，将数据存入role（角色表）基础的增删改查不多说
role.png
点击分配用户
image.png
之前添加的两个用户展现出来，如果选择用户点击保存，则后台将用户的userId和这个角色的roleId保存到roleUser表中
同理，分配菜单和摄像头都是这个流程。
那么，如果菜单分配好了，假设，我给“最高管理者”这个角色分配了四个菜单，“次管理者”这个角色分配了两个菜单，将用户“校长”分配给“最高管理者”这个角色。也就是说，校长这个用户登录进入这个平台的时候应该只能看见四个菜单。
新建一个控制器：platformController
package com.lencity.securitymanagementplatform.controller;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import com.alibaba.fastjson.JSONObject;
import com.lencity.securitymanagementplatform.data.entity.Camera;
import com.lencity.securitymanagementplatform.data.entity.Menu;
import com.lencity.securitymanagementplatform.data.entity.Role;
import com.lencity.securitymanagementplatform.data.entity.RoleMenu;
import com.lencity.securitymanagementplatform.data.entity.RoleUser;
import com.lencity.securitymanagementplatform.data.entity.User;
import com.lencity.securitymanagementplatform.data.service.MenuService;
import com.lencity.securitymanagementplatform.data.service.RoleMenuService;
import com.lencity.securitymanagementplatform.data.service.RoleUserService;
import com.lencity.securitymanagementplatform.data.service.UserService;
@Controller
@Scope("session")
@RequestMapping("")
public class PlatformController {
@Autowired
private UserService userService;
@Autowired
private RoleUserService roleUserService;
@Autowired
private RoleMenuService roleMenuService;
@Autowired
private MenuService menuService;
@GetMapping("/")
public String index() {
return "forward:/login.html";
}
@PostMapping(value = "/login", produces = "application/json;charset=utf-8")
@ResponseBody
public String login(String name, String password, HttpSession session) {
User user = userService.login(name, password);
if (user == null) {
session.removeAttribute("loginUser");
return "0";
}
session.setAttribute("loginUser", user);
return "1";
}
@RequestMapping(value = "/logout", produces = "application/json;charset=utf-8")
@ResponseBody
public String logout(HttpSession session) {
session.removeAttribute("user");
return "1";
}
@RequestMapping(value = "/changePassword", produces = "application/json;charset=utf-8")
@ResponseBody
public String changePassword(String oldPassword, String newPassword, HttpSession session) {
User user = (User) session.getAttribute("user");
boolean result = userService.changePassword(user.getName(), oldPassword, newPassword);
return result ? "1" : "0";
}
}
JS
function login() {
$("#form").ajaxSubmit({
type : 'POST',
cache : false,
success : function(result) {
if (result == "0") {
alert("帐号或密码错误，请重新输入！");
} else {
location.href = "user";
}
}
});
}
接下来就是拦截器
platformInterceptor
package com.lencity.securitymanagementplatform.interceptor;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import com.lencity.securitymanagementplatform.data.entity.Menu;
import com.lencity.securitymanagementplatform.data.entity.RoleMenu;
import com.lencity.securitymanagementplatform.data.entity.RoleUser;
import com.lencity.securitymanagementplatform.data.entity.User;
import com.lencity.securitymanagementplatform.data.service.MenuService;
import com.lencity.securitymanagementplatform.data.service.ModuleService;
import com.lencity.securitymanagementplatform.data.service.RoleMenuService;
import com.lencity.securitymanagementplatform.data.service.RoleUserService;
@Component
public class PlatformInterceptor implements HandlerInterceptor {
@Autowired
private ModuleService moduleService;
@Autowired
private RoleMenuService roleMenuService;
@Autowired
private RoleUserService roleUserService;
@Autowired
private MenuService menuService;
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
HttpSession session = request.getSession();
if (session.getAttribute("moduleMenus") == null) {
session.setAttribute("moduleMenus", moduleService.getModuleMenus());
}
User user = (User) session.getAttribute("loginUser");
if (user != null) {
RoleUser roleUser = roleUserService.getUserByUserId(user.getId());
List roleMenus = roleMenuService.getRoleMenuByRoleId(roleUser.getRoleId());
List 
image.png
package com.lencity.securitymanagementplatform;
import java.util.ArrayList;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import com.lencity.securitymanagementplatform.interceptor.ModuleInterceptor;
import com.lencity.securitymanagementplatform.interceptor.PlatformInterceptor;
@Configuration
public class PlatformWebConfiguration implements WebMvcConfigurer {
@Autowired
private PlatformInterceptor platformInterceptor;
@Autowired
private ModuleInterceptor moduleInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
List platformExcludePathes = new ArrayList<>();
platformExcludePathes.add("/moduleInterface/**");
platformExcludePathes.add("/");
platformExcludePathes.add("/platform/**");
platformExcludePathes.add("/login.html");
platformExcludePathes.add("/login");
platformExcludePathes.add("/publicData/**");
platformExcludePathes.add("/library/**");
platformExcludePathes.add("/data/**");
platformExcludePathes.add("/image/**");
platformExcludePathes.add("/js/**");
platformExcludePathes.add("/*.txt");
registry.addInterceptor(platformInterceptor).addPathPatterns("/**").excludePathPatterns(platformExcludePathes);
registry.addInterceptor(moduleInterceptor).addPathPatterns("/moduleInterface/**");
WebMvcConfigurer.super.addInterceptors(registry);
}
}
通过拦截器，userId去查询roleId，然后通过roleId去查询roleMenu 的菜单id
，最后通过菜单id去查询菜单表。存入session中。
menu.html
循环遍历session中的menus，展现如下效果
菜单.png
Over~