登录拦截器使用

config层配置

@Configuration
public class Loginconfig implements WebMvcConfigurer {
    @Autowired
    private LoginInterceptor loginInterceptor;
//   添加拦截器路径
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
//        放行登录和注册
        registry.addInterceptor(loginInterceptor).excludePathPatterns("/login","/register");
    }
}

重写方法WebMvcConfigurer 的添加拦截器addInterceptors，添加拦截的路径。

拦截器

@Component
public class LoginInterceptor implements HandlerInterceptor {
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//     拦截器检查是否有token
        String token = request.getHeader("Authorization");
        Map<String,Object> map =  JwtUtil.parseToken(token);
        Integer userid = (Integer) map.get("id");
        try{
//            根据前端token获取redis的token
            ValueOperations<String, String> stringStringValueOperations = stringRedisTemplate.opsForValue();
            String RedisToken =  stringStringValueOperations.get(userid.toString());
            if (RedisToken==null)
            {
                throw  new RuntimeException();
            }
//            放行
            Map<String, Object> UsertMap = JwtUtil.parseToken(token);
//            把含有用户名字的信息放进线程池
            ThreadLocalUtil.set(UsertMap);
            return true;
        }catch (Exception e){
//            不放行
            response.setStatus(401);
            return false;
        }
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        ThreadLocalUtil.remove();
    }

拦截器中主要功能是先去检查客户端页面是否有token信息，从前端的request.getHeader(“Authorization”);获取得到token信息。使用JwtUtil工具类解析得到用户信息。

public class JwtUtil {

    private static final String KEY = "lcc练习jwt";
	
	//接收业务数据,生成token并返回
    public static String genToken(Map<String, Object> claims) {
        return JWT.create()
                .withClaim("claims", claims)
                .withExpiresAt(new Date(System.currentTimeMillis() + 1000 * 60 * 60 * 12))
                .sign(Algorithm.HMAC256(KEY));
    }

	//接收token,验证token,并返回业务数据
    public static Map<String, Object> parseToken(String token) {
        return JWT.require(Algorithm.HMAC256(KEY))
                .build()
                .verify(token)
                .getClaim("claims")
                .asMap();
    }

}
上段是工具类，在pom文件导入以下依赖
<!--		jwt参数校验-->
		<dependency>
			<groupId>com.auth0</groupId>
			<artifactId>java-jwt</artifactId>
			<version>4.3.0</version>
		</dependency>

这里stringRedisTemplate是pom文件导入的依赖

<!--		Redis-->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-redis</artifactId>
		</dependency>
	</dependencies>