JWT实现单点登录和鉴权

素颜马尾好姑娘i 2023-02-18 03:13 21阅读 0赞

1.自定义JWTUtils工具类,根据用户名生成token

import com.auth0.jwt.JWT;
    import com.auth0.jwt.JWTVerifier;
    import com.auth0.jwt.algorithms.Algorithm;
    
    import java.util.Date;
    
    /** * JWT工具类 */
    public class JwtUtil { 
        //定义秘钥:类似于盐值加密
        private final static String SECRET = "woniuxy";
        //定义签发人
        private final static String ISSUER = "java";
        //指定token过期时间
        private final static int EXPIRES = 30 * 60 * 1000;
    
        //生成token,可以携带自定义信息（用户名）
        public static String create(String uname) { 
            //定义加密算法
            Algorithm algorithm = Algorithm.HMAC256(SECRET);
            Date now = new Date();
            //过期时间
            Date expires = new Date(now.getTime() + EXPIRES);
            String token = JWT.create()
                    .withIssuer(ISSUER)
                    .withIssuedAt(now)
                    .withExpiresAt(expires)
                    .withClaim("uname", uname)
                    .sign(algorithm);
            return token;
        }
    
        //验证token是否合法
        public static boolean verify(String token) { 
            try { 
                Algorithm algorithm = Algorithm.HMAC256(SECRET);
                JWTVerifier build = JWT.require(algorithm).withIssuer(ISSUER).build();
                build.verify(token);
                return true;
            } catch (Exception e) { 
                return false;
            }
        }
    
        public static String getUname(String token){ 
            try{ 
                return  JWT.decode(token).getClaim("uname").asString();
            }catch (Exception e){ 
                return null;
            }
        }

2.在登录操作时，使用工具类生成token  
![在这里插入图片描述][20200615173900547.png]  
3.前端页面存token，存在于客户端  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70]  
4.在其他html页面取得token  
![在这里插入图片描述][20200615175524127.png]  
5.后台取得token,  
由于token是存在请求头中，所以在前段中，必须加上，将其存于请求头  
![在这里插入图片描述][20200615175632862.png]  
6.后台取得token如下  
![在这里插入图片描述][20200615175841397.png]  
单点登录就做好啦。

## .鉴权： ##

实现方式是自定义注解使用拦截器进行拦截，然后根据数据库中查询到的权限，token中区的的用户，查询该用户是否有这个权限

1.自定义注解  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70 1]  
2.service实现类  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70 2]  
3.拦截器\`

import com.fasterxml.jackson.databind.ObjectMapper;
    import com.woniu.logistics.entity.ResponseResult;
    import com.woniuxy.anno.RequierPermissions;
    import com.woniuxy.service.AuthPermissions;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.method.HandlerMethod;
    import org.springframework.web.servlet.HandlerInterceptor;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.lang.reflect.Method;
    
    public class AuthHandlerIntercepytor implements HandlerInterceptor { 
        //interceptor注入bean，对象为空，必须注入当前拦截器的bean
        @Autowired
        AuthPermissions authPermissions;
    
        @Override
        public boolean preHandle(HttpServletRequest request,
                                 HttpServletResponse response, Object handler) throws Exception { 
            System.out.println("执行权限拦截");
            //取得token
            String token = request.getHeader("token");
    
            System.out.println("token是："+token);
            //判断，当前的处理器是一个方法处理器才执行权限判断，权限注解是添加在Controller方法上的
            if (handler instanceof HandlerMethod) { 
                Method method = ((HandlerMethod) handler).getMethod();
                if (method.isAnnotationPresent(RequierPermissions.class)) { 
                    RequierPermissions requierPermissions = method.getAnnotation(RequierPermissions.class);
                    String permission = requierPermissions.value();
                    System.out.println("调用的方法：" + method + "，需要的权限：" + permission);
                    if (!authPermissions.hasPermission(token, permission)) { 
                        //没有权限,拦截
                        System.out.println("你没权限");
                        response.getWriter().write(new ObjectMapper().writeValueAsString(
                                new ResponseResult<String>(403, "nohaspermission")));
                        return false;
                    }
                }
            }
            System.out.println("有权限");
            //放行
            return true;
        }
    }

4.controller测试  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70 3]

实现的比较简单！

[20200615173900547.png]: https://img-blog.csdnimg.cn/20200615173900547.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200615175431447.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1,size_16,color_FFFFFF,t_70
[20200615175524127.png]: https://img-blog.csdnimg.cn/20200615175524127.png
[20200615175632862.png]: https://img-blog.csdnimg.cn/20200615175632862.png
[20200615175841397.png]: https://img-blog.csdnimg.cn/20200615175841397.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200615184824383.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200615185004351.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20200615185232949.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1,size_16,color_FFFFFF,t_70