【SpringBoot】登录认证和 JWT

1. 登录功能

@PostMapping("/login")
public Result<String> login(@Pattern(regexp = "^\\S{5,16}$") String username, @Pattern(regexp = "^\\S{5,16}$") String password) {
    User loginUser = userService.findByUserName(username);
    if (loginUser == null) {
        return Result.error("用户名错误");
    }
    if (Md5Util.getMD5String(password).equals(loginUser.getPassword())) {
        Map<String, Object> claims = new HashMap<>();
        claims.put("id", loginUser.getId());
        claims.put("username", loginUser.getUsername());
        String token = JwtUtil.genToken(claims);
        return Result.success(token);
    }
    return Result.error("密码错误");
}

2. JWT

定义了一种简洁的、自包含的格式，用于通信双方以json数据格式安全的传输信息。

<dependency>
    <groupId>com.auth0</groupId>
    <artifactId>java-jwt</artifactId>
    <version>4.3.0</version>
</dependency>

JwtUtil

package com.heo.utils;

import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;

import java.util.Date;
import java.util.Map;

public class JwtUtil {

    private static final String KEY = "itheima";
	
	//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();
    }

}

ArticleController

@RestController
@RequestMapping("/article")
public class ArticleController {
    @GetMapping("/list")
    public Result<String> list(/*@RequestHeader(name = "Authorization") String token, HttpServletResponse response*/) {
        /*try {
            Map<String, Object> claims = JwtUtil.parseToken(token);
            return Result.success("所有的文章。。。");
        } catch (Exception e) {
            response.setStatus(401);
            return Result.error("未登录");
        }*/
        return Result.success("所有的文章。。。");
    }
}

一般情况下，我们需要写成全局登录响应拦截器。

interceptor/LoginInterceptor

@Component
public class LoginInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String token = request.getHeader("Authorization");
        try {
            Map<String, Object> claims = JwtUtil.parseToken(token);
            return true;
        } catch (Exception e) {
            response.setStatus(401);
            return false;
        }
    }
}

然后进行全局配置

config/WebConfig

@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Autowired
    private LoginInterceptor loginInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(loginInterceptor).excludePathPatterns("/user/login", "user/register");
    }
}