JWT+SpringBoot+SpringMVC参数解析器

大家以前都使用过session存储信息,有的交给容器创建,有的存储到mysql或者redis,这次项目用到了JWT，我们把用户的信息和登录的过期时间都封装到一个token字符串里,客户端每次请求只需要在头信息里携带token即可,话不多说,下面是目录结构.

一.annonation注解

package com.demo.annotation;

import java.lang.annotation.*;

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface IgnoreLogin {
}

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该注解主要作用是过滤掉请求拦截器,使用该注解就不会对该请求进行拦截(权限校验),具体使用下面讲.

package com.demo.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 登录用户信息
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
public @interface LoginUser {}
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该注解作用是SpringMVC参数解析器,类似于RequestBody注解(希望大家了解springmvc的参数解析机制),和我们后面的resolver相关联.

二.bean实体类

package com.demo.bean;

public class User {
    private long userId;
    private String userName;
    private String password;
    忽略get/set
}

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我们的用户信息

package com.demo.bean;

public class Business {
    private String str;
    private int num;
    忽略get/set
}

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我们的业务参数

三.config配置信息

package com.demo.config;

import com.demo.interceptor.AuthorizationInterceptor;
import com.demo.resolver.UserArgumentResolver;
import org.springframework.beans.factory.annotation.Autowired;
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;

/**
 * MVC配置
 */
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Autowired
    private AuthorizationInterceptor authorizationInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(authorizationInterceptor).addPathPatterns("/**");
        //注入我们自定义的拦截器,拦截所有请求
    }

    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
        resolvers.add(new UserArgumentResolver());
        //注入我们的用户参数解析器
    }
}
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四.controller

package com.demo.controller;

import com.demo.annotation.IgnoreLogin;
import com.demo.annotation.LoginUser;
import com.demo.bean.Business;
import com.demo.bean.User;
import com.demo.util.JwtUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;


@RestController
public class UserController {

    private Logger logger = LoggerFactory.getLogger(getClass());

    @Autowired
    private JwtUtils jwtUtils;

    @PostMapping(value = "/login")
    @IgnoreLogin
    public String login() {
        //在此 我们不做登录检验 假设检验成功

        User user = new User();
        user.setUserId(9527);
        user.setUserName("小星星");
        return jwtUtils.generateToken(user);//这里只是为了测试只返回token,(请求不含IgnoreLogin注解时需要将token放在头信息里)
    }

    @PostMapping("/business")
    public User business(@RequestBody Business business, @LoginUser User user) {//在业务逻辑可以使用注解将我们的user注入进来
        logger.info("用户信息参数id:{},姓名:{}", user.getUserId(), user.getUserName());
        logger.info("我们的业务参数:{},{}", business.getStr(), business.getNum());
        return user;
    }
}

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可以看到当我们登陆成功后我们可以生成一个token字符串返回给客户端,这个字符串包含了用户信息和时间信息(jwt机制),同时我们做了一个模仿业务的请求,business是我们的业务参数,user是我们根据客户端上发的token解析出来的,下面会讲到如何解析.可以看到只要我们需要user的参数,我们就可以直接使用LoginUser注解和User就可以直接得到,非常方便,客户端并不需要将我们的用户信息参杂到我们的业务参数中.相对安全。

五.exception

package com.demo.exception;

public class RRException extends RuntimeException {

    private static final long serialVersionUID = 1L;

    private String msg;
    private int code = 500;

}

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这里我就不解析了，根据需求可以和客户端协商相应的错误码

六.interceptor拦截器

package com.demo.interceptor;

import com.demo.annotation.IgnoreLogin;
import com.demo.exception.RRException;
import com.demo.util.JwtUtils;
import io.jsonwebtoken.Claims;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 权限(Token)验证
 */
@Component
public class AuthorizationInterceptor extends HandlerInterceptorAdapter {

    @Autowired
    private JwtUtils jwtUtils;

    public static final String USER_KEY = "user";

    private Logger logger = LoggerFactory.getLogger(getClass());

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        if (!(handler instanceof HandlerMethod) || ((HandlerMethod) handler).
                getMethodAnnotation(IgnoreLogin.class) != null) {
            //如果不是HandlerMethod或者忽略登录
            logger.info("无需token校验,handler:{}", handler);
            return true;
        }

        //获取用户凭证
        String token = request.getHeader(jwtUtils.getHeader());
        if (StringUtils.isBlank(token)) {
            token = request.getParameter(jwtUtils.getHeader());
        }

        //凭证为空
        if (StringUtils.isBlank(token)) {
            throw new RRException(jwtUtils.getHeader() + "不能为空", HttpStatus.UNAUTHORIZED.value());
        }

        Claims claims = jwtUtils.getClaimByToken(token);
        if (claims == null || jwtUtils.isTokenExpired(claims.getExpiration())) {
            throw new RRException(jwtUtils.getHeader() + "失效，请重新登录", HttpStatus.UNAUTHORIZED.value());
        }

        //设置userId到request里，后续根据userId，获取用户信息
        request.setAttribute(USER_KEY, jwtUtils.getUser(claims));
        return true;
    }
}

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我们会过滤掉不是HandlerMethod的请求和带有IgnoreLogin的注解(并不是所有方法都需要校验,例如登录请求,支付回调请求),我们会取出客户端发出的token,解析出来并判断是否过期,没有token或者已过期我们可以需要返回一个错误码给客户端然后重新登录,当我们校验成功后我们会取出用户信息放入到request里(后面会在参数解析器里解析出来),这也是这个拦截器的精髓,既能校验又能获取用户的信息.

七.resolver参数解析器

package com.demo.resolver;

import com.demo.annotation.LoginUser;
import com.demo.bean.User;
import com.demo.interceptor.AuthorizationInterceptor;
import org.springframework.core.MethodParameter;
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.servlet.http.HttpServletRequest;

/**
 * 用户参数解析器
 */
public class UserArgumentResolver implements HandlerMethodArgumentResolver {

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.hasParameterAnnotation(LoginUser.class);
    }

    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
        HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
        User user = (User) request.getAttribute(AuthorizationInterceptor.USER_KEY);
        return user;
    }
}

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springmvc的参数解析器,需要继承HandlerMethodArgumentResolver,有两个方法,第一个就是支持什么类型的参数,可以看到我们支持拥有LoginUser注解的参数,第二个方法是从request里取出我们在拦截器中放入的user并返回,这样就实现了user对象的注入.

八.JwtUtils

package com.demo.util;

import com.alibaba.fastjson.JSONObject;
import com.demo.bean.User;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

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

/**
 * jwt工具类
 */
@Component
@ConfigurationProperties(prefix = "jwt")
public class JwtUtils {

    private Logger logger = LoggerFactory.getLogger(getClass());

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

    /**
     * 生成jwt token
     */
    public String generateToken(User user) {
        Date nowDate = new Date();

        //过期时间
        Date expireDate = new Date(nowDate.getTime() + expire * 1000);
        return Jwts.builder()
                .setHeaderParam("typ", "JWT")
                .setSubject(JSONObject.toJSONString(user))
                .setIssuedAt(nowDate)
                .setExpiration(expireDate)
                .signWith(SignatureAlgorithm.HS512, secret)
                .compact();
    }

    /**
     * 解析出来claim
     * @param token
     * @return
     */
    public Claims getClaimByToken(String token) {
        try {
            return Jwts.parser().setSigningKey(secret).parseClaimsJws(token).getBody();
        } catch (Exception e) {
            logger.debug("validate is token error ", e);
            return null;
        }
    }

    /**
     * 得到user
     * @param claims
     * @return
     */
    public User getUser(Claims claims) {
        return JSONObject.parseObject(claims.getSubject(), User.class);
    }

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

    public String getSecret() {
        return secret;
    }

    public void setSecret(String secret) {
        this.secret = secret;
    }

    public long getExpire() {
        return expire;
    }

    public void setExpire(long expire) {
        this.expire = expire;
    }

    public String getHeader() {
        return header;
    }

    public void setHeader(String header) {
        this.header = header;
    }
}

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expire过期时间,secret密钥,header头信息名称 这些数据在application.yml里,这里我们会根据User对象生成一个token字符串,根据token取出claims对象,这里就包含了我们的过期时间和之前我们所存的user信息.

九.springboot启动和yml参数

package com.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringBootStart {

    public static void main(String[] agrs) {
        SpringApplication.run(SpringBootStart.class, agrs);
    }
}

application.yml
jwt:
    #加密秘钥
    secret: f4e2e5203fg45sf45g4de581c0f9eb5
    #token，单位秒
    expire: 6000
    header: token


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