1、基于session的认证

流程：

• 用户认证成功后，服务端生成用户数据保存在session中
• 服务端返回给客户端session id (sid），被客户端存到自己的cookie中
• 客户端下次再请求，就带上sid，服务端校验是否存在对应的session，存在则不要求用户再登录了

2、Demo

基于Session的认证机制由Servlet制定规范，Serlvet容器以实现，HttpSession相关方法：

方法	用途
HttpSession getSession(Boolean create)	获取当前HttpSession对象
void setAttribute(String name,Object value)	向session中存放对象
object getAttribute(String name)	从session中获取对象
void removeAttribute(String name);	移除session中对象
void invalidate()	使HttpSession失效

准备实体类：

@Data
public class AuthenticationRequestDto {/*** 用户名*/private String username;/*** 密码*/private String password;
}

@Data
@AllArgsConstructor
public class UserVo {private String id;private String username;private String password;private String fullname;private String mobile;
}

session实现认证

用Map模拟查询数据库，存储用户信息：

@Service
public class AuthenticationServiceImpl implements AuthenticationService {private final Map<String, UserVo> userMap = new HashMap<>();{userMap.put("zhangsan", new UserVo("1010", "zhangsan", "123", "zhangSan", "133443"));userMap.put("lisi", new UserVo("1011", "lisi", "456", "liSi", "144553"));}@Overridepublic UserVo auth(AuthenticationRequestDto dto) {if (dto == null|| StringUtils.isEmpty(dto.getUsername())|| StringUtils.isEmpty(dto.getPassword())) {throw new RuntimeException("账户或密码为空");}//模拟查询数据库UserVo vo = getUserVo(dto.getUsername());if (null == vo) {throw new RuntimeException("用户不存在");}if (!vo.getPassword().equals(dto.getPassword())) {throw new RuntimeException("密码错误");}return vo;}public UserVo getUserVo(String username) {return userMap.get(username);}}

定义三个接口，登录，服务端保存session，登出，让session失效。以及一个资源接口，查看当前是登录访问资源，还是未登录访问资源

@RestController
public class Controller {@Resourceprivate AuthenticationService authenticationService;@GetMapping(value = "/login")public String login(AuthenticationRequestDto dto, HttpSession session) {UserVo userVo = authenticationService.auth(dto);//用户信息存入sessionsession.setAttribute("sid", userVo);return userVo.getFullname() + " success login";}@GetMapping("/logout")public String logout(HttpSession session) {//让session失效session.invalidate();return " success logout";}@GetMapping("/r1")public String resource(HttpSession session) {String fullName = null;Object result = session.getAttribute("sid");if (result != null) {fullName = ((UserVo) result).getFullname();} else {fullName = "no login";}return fullName + " access resource ... ";}}

测试：

登录后访问资源接口：

退出登录后，再访问资源接口：

session实现授权

修改实体类，加个权限字段，存储用户权限

@Data
@AllArgsConstructor
public class UserVo {private String id;private String username;private String password;private String fullname;private String mobile;/*** 用户权限*/private Set<String> authorities;
}

实例代码块创建用户到map的代码做调整：

{Set<String> auth1 = new HashSet<>();auth1.add("p1");   //对应/r1这个接口资源Set<String> auth2 = new HashSet<>();auth2.add("p2");   //对应/r2这个接口资源userMap.put("zhangsan", new UserVo("1010", "zhangsan", "123", "zhangSan", "133443", auth1));userMap.put("lisi", new UserVo("1011", "lisi", "456", "liSi", "144553", auth2));}

加个测试资源接口/r2

@GetMapping("/r2")public String resource2(HttpSession session) {String fullName = null;Object result = session.getAttribute("sid");if (result != null) {fullName = ((UserVo) result).getFullname();} else {fullName = "no login";}return fullName + " access resource ... ";}

写拦截器：

@ComponentScan
public class SimpleAuthInterceptor implements HandlerInterceptor {/*** 校验用户请求的url是否在权限范围中*/@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {//从http请求中获取session对象，再拿当前HttpSession对象Object object = request.getSession().getAttribute("sid");//没有认证if (object == null) {writeContent(response, "请登录");}UserVo userVo = (UserVo) object;//请求的urlString requestURI = request.getRequestURI();assert userVo != null;if (userVo.getAuthorities().contains("p1") && requestURI.contains("/r1")) {return true;}if (userVo.getAuthorities().contains("p2") && requestURI.contains("/r2")) {return true;}//拒绝访问writeContent(response,"没有权限，拒绝访问");return false;}private void writeContent(HttpServletResponse response, String msg) throws IOException {response.setContentType("text/html;charset=utf-8");PrintWriter writer = response.getWriter();writer.print(msg);writer.close();}
}

拦截器add并放行/login，只测/r**接口

@Configuration
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {/*** 视图解析器*/@Beanpublic InternalResourceViewResolver viewResolver(){InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();viewResolver.setPrefix("/static/");  //前缀viewResolver.setSuffix(".jsp");  //后缀return viewResolver;}@Overridepublic void addViewControllers(ViewControllerRegistry registry) {registry.addViewController("/").setViewName("login");}@Overridepublic void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(new SimpleAuthInterceptor()).addPathPatterns("/r**");   //新加进来的拦截器只针对r打头的接口，否则login接口也会被拦截要求登录}
}

测试，登录zhangsan，其有r1权限，访问r2接口：