JWT与自定义注解

傷城~ 2022-11-09 12:35 188阅读 0赞

# JWT #

### JWTUtil ###

package com.example.util;
    
    import com.auth0.jwt.JWT;
    import com.auth0.jwt.algorithms.Algorithm;
    import com.auth0.jwt.interfaces.Claim;
    import com.auth0.jwt.interfaces.DecodedJWT;
    import org.springframework.stereotype.Service;
    
    import java.util.Date;
    import java.util.HashMap;
    
    @Service
    public class JWTUtils {
        
        //token需要有一个过期时间
        public static final long TOKEN_EXPIRE = 60 * 1000 * 1000;
        //token的生成需要一个加密的密钥
        public static final String TOKEN_SECRET = "194ce5d0b89c47ff6b30bfb491f9dc26";
    
        public static void main(String[] args) {
        
            //        String nihao = DigestUtils.md5DigestAsHex("nihao".getBytes());
            //        System.out.println(nihao);
    //        String token = generateToken("1");
    //        System.out.println(verifyToken(token));
    //        System.out.println(getClaim(token));
        }
    
        //生成并发放给用户一个token
        public  String generateToken(String id) {
        
            //过期时间的计算
            Date date = new Date(System.currentTimeMillis() + TOKEN_EXPIRE);
            //设置一个算法
            Algorithm algorithm = Algorithm.HMAC256(TOKEN_SECRET.getBytes());
            //设置一个header
            HashMap<String, Object> header = new HashMap<String, Object>();
            header.put("alg", "HMAC256");
            header.put("type", "JWT");
            String token = JWT.create().withHeader(header).withClaim("id", id).withExpiresAt(date).sign(algorithm);
            return token;
        }
    
        //验证token是否正确
        public  boolean verifyToken(String token) {
        
            try {
        
                Algorithm algorithm = Algorithm.HMAC256(TOKEN_SECRET.getBytes());
                DecodedJWT verify = JWT.require(algorithm).build().verify(token);
            } catch (Exception e) {
        
                return false;
            }
            return true;
        }
    
        //从token中解答出我们加密的信息
        public  String getClaim(String token) {
        
            DecodedJWT decode = JWT.decode(token);
            Claim id = decode.getClaim("id");
    //        Claim info = decode.getClaim("info");
    //        System.out.println(Arrays.toString(info.asArray(String.class)));
            return id.asString();
        }
    }

### 自定义注解 ###

package com.example.annotaion;
    
    import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    
    @Target(ElementType.PARAMETER)
    @Retention(RetentionPolicy.RUNTIME)
    public @interface LoginUser {
        
    }

package com.example.annotaion;
    
    import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    
    @Retention(RetentionPolicy.RUNTIME)
    @Target({
        ElementType.TYPE,ElementType.METHOD,ElementType.PARAMETER})
    public @interface Token {
        
        String value() default "";
    }

### 配置resolver ###

package com.example.resolver;
    
    import com.example.annotaion.Token;
    import com.example.entity.User;
    import com.example.util.JWTUtils;
    import org.springframework.core.MethodParameter;
    import org.springframework.stereotype.Service;
    import org.springframework.web.bind.support.WebDataBinderFactory;
    import org.springframework.web.context.request.NativeWebRequest;
    import org.springframework.web.method.support.HandlerMethodArgumentResolver;
    import org.springframework.web.method.support.ModelAndViewContainer;
    
    import javax.annotation.Resource;
    
    public class TokenResolver implements HandlerMethodArgumentResolver {
        
        @Resource
        JWTUtils jwtUtils;
    
        @Override
        public boolean supportsParameter(MethodParameter methodParameter) {
        
            return methodParameter.getParameterType().isAssignableFrom(String.class)&&methodParameter.hasParameterAnnotation(Token.class);
        }
    
        @Override
        public Object resolveArgument(MethodParameter methodParameter, ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest, WebDataBinderFactory webDataBinderFactory) throws Exception {
        
    
            String token = nativeWebRequest.getParameter("token");
            boolean b = jwtUtils.verifyToken(token);
            if (b){
        
                String id = jwtUtils.getClaim(token);
                //数据库操作
                return new User(10,23,"silk");
            }
            return null;
        }
    }

package com.example.config;
    
    import com.example.annotaion.Token;
    import com.example.resolver.TokenResolver;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.method.support.HandlerMethodArgumentResolver;
    import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
    
    import java.util.List;
    
    @Configuration
    class MyConfig implements WebMvcConfigurer {
        
        @Override
        public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
        
            resolvers.add(new TokenResolver());
        }
    
        //    @Override
        //    public void addInterceptors(InterceptorRegistry registry) {
        
        //        registry.addInterceptor()
        //    }
    }

### 实体类 ###

package com.example.entity;
    
    import lombok.Data;
    
    @Data
    public class User {
        
        int id;
        int age;
        String name;
    
        public User(int id, int age, String name) {
        
            this.id = id;
            this.age = age;
            this.name = name;
        }
    }

### controller ###

package com.example.controller;
    
    import com.example.annotaion.LoginUser;
    import com.example.annotaion.Token;
    import com.example.entity.User;
    import com.example.util.JWTUtils;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.annotation.Resource;
    import javax.servlet.http.HttpServletRequest;
    import java.util.HashMap;
    import java.util.Map;
    
    @RestController
    @Token("class token")
    public class HelloController {
        
        @Resource
        JWTUtils jwtUtils;
    
        @RequestMapping("/login/{id}")
        public Map login(@PathVariable String id) {
        
            String token = jwtUtils.generateToken(id);
            HashMap<String, Object> map = new HashMap<>();
            map.put("code", 200);
            map.put("token", token);
            return map;
        }
    
        @RequestMapping("pay")
        @Token("methdo token")
        public Map pay(@Token User User) {
        
            //常规的做法
            //验证token//
            //解析出用户id
            //权限校验
            //这种实现好吗
    //        String token = request.getParameter("token");
    //        boolean b = jwtUtils.verifyToken(token);
    //        String id = null;
    //        if (b) {
        
    //            id = jwtUtils.getClaim(token);
    //        }
            System.out.println("id");
            HashMap<String, Object> map = new HashMap<>();
            map.put("code", 200);
            map.put("id", "20");
            return map;
        }
    }