=============
后端_令牌过滤
=============

1 添加依赖

/pom.xml：

...
<dependency>
    <groupId>org.crazycake</groupId>
    <artifactId>shiro-redis-spring-boot-starter</artifactId>
    <version>3.3.1</version>
</dependency>
<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.3.1</version>
</dependency>
<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.3.3</version>
</dependency>
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt</artifactId>
    <version>0.9.1</version>
</dependency>
...

2 添加属性

/src/main/resources/META-INF/spring-devtools.properties：

restart.include.shiro-redis=/shiro-[\\w-\\.]+jar

3 添加配置

/src/main/resources/application.yml：

...
shiro-redis:
  enabled: true
  redis-manager:
    host: 127.0.0.1:6379
weihome:
  jwt:
    # 加密秘钥
    secret: f4e2e52034348f86b67cde581c0f9eb5
    # 有效秒数(7天)
    expire: 604800
    header: Authorization
...

4 添加JWT工具类

/src/main/java/com/weihome/barblog/shiro/JwtUtils.java：

/**
 * JWT工具类
 */
@Slf4j
@Data
@Component
@ConfigurationProperties(prefix = "weihome.jwt")
public class JwtUtils {

    private String secret;
    private long expire;
    private String header;

    /**
     * 生成令牌
     */
    public String generateToken(long userId) {
        Date nowDate = new Date();
        //过期时间
        Date expireDate = new Date(nowDate.getTime() + expire * 1000);

        return Jwts.builder()
                .setHeaderParam("typ", "JWT")
                .setSubject(userId+"")
                .setIssuedAt(nowDate)
                .setExpiration(expireDate)
                .signWith(SignatureAlgorithm.HS512, secret)
                .compact();
    }

    public Claims getClaimByToken(String token) {
        try {
            return Jwts.parser()
                    .setSigningKey(secret)
                    .parseClaimsJws(token)
                    .getBody();
        }catch (Exception e){
            log.debug("validate is token error ", e);
            return null;
        }
    }

    /**
     * 令牌是否过期
     * @return  true：过期
     */
    public boolean isTokenExpired(Date expiration) {
        return expiration.before(new Date());
    }
}

5 添加JWT令牌类

/src/main/java/com/weihome/barblog/shiro/JwtToken.java：

/**
 * JWT令牌类
 */
public class JwtToken implements AuthenticationToken {
    private String token; // 令牌字符串

    public JwtToken(String token) {
        this.token = token;
    }

    @Override
    public Object getPrincipal() {
        return token;
    }

    @Override
    public Object getCredentials() {
        return token;
    }
}

6 添加JWT过滤器类

/src/main/java/com/weihome/barblog/shiro/JwtFilter.java：

/**
 * JWT过滤器类
 */
@Component
public class JwtFilter extends AuthenticatingFilter {
    @Autowired
    JwtUtils jwtUtils;

    /**
     * 接受或拒绝请求
     * 无令牌：接受请求
     * 令牌无效：抛出异常
     * 令牌有效：根据身份认证结果决定接受或拒绝请求
     */
    @Override
    protected boolean onAccessDenied(
        ServletRequest servletRequest, ServletResponse servletResponse)
        throws Exception {
        HttpServletRequest request =
            (HttpServletRequest) servletRequest;

        // 从请求头中获取令牌字符串
        String token = request.getHeader("Authorization");
        if (StringUtils.isEmpty(token)) // 无令牌
            return true; // 接受请求

        Claims claim = jwtUtils.getClaimByToken(token);
        if (claim == null || jwtUtils.isTokenExpired(
            claim.getExpiration())) // 令牌无效
            throw new ExpiredCredentialsException("令牌无效，重新登录");

        return executeLogin(servletRequest, servletResponse); // 身份认证
    }

    /**
     * 身份认证过程中调用此方法
     */
    @Override
    protected AuthenticationToken createToken(
        ServletRequest servletRequest, ServletResponse servletResponse)
        throws Exception {
        HttpServletRequest request =
            (HttpServletRequest) servletRequest;

        // 从请求头中获取令牌字符串
        String token = request.getHeader("Authorization");
        if (StringUtils.isEmpty(token)) // 无令牌
            return null; // 无需身份认证

        return new JwtToken(token); // 返回JWT令牌用于身份认证
    }

    /**
     * 身份认证失败时调用此方法
     */
    @Override
    protected boolean onLoginFailure(
        AuthenticationToken authcToken,
        AuthenticationException authcException,
        ServletRequest servletRequest,
        ServletResponse servletResponse) {
        HttpServletResponse response =
            (HttpServletResponse) servletResponse;

        Throwable throwable = authcException.getCause() == null ?
            authcException : authcException.getCause();
        Result result = Result.error(throwable.getMessage());
        String json = JSONUtil.toJsonStr(result);

        try {
            // 将包含异常信息的Json字符串写入响应
            response.getWriter().print(json);
        }
        catch (IOException ioException) {
        }

        return false;
    }
}