JWT 请求流程
用户使用账号和密码发起POST 请求；
服务器使用私钥创建一个JWT；
服务器返回这个JWT 给浏览器；
浏览器将该JWT 串在请求头中像服务器发送请求；
服务器验证该JWT；
返回响应的资源给浏览器。
<!-- 引入jwt-->
<dependency>
<groupId>com.auth0</groupId>
<artifactId>java-jwt</artifactId>
<version>3.8.2</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
用户类
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
????private Integer id;
????private String userName;
????private String password;
}
Jwt工具类
/**
* Jwt工具类进行token的生成和认证
*/
public class JwtUtil {
private static final Logger logger = LoggerFactory.getLogger(JwtUtil.class);
/**
* 密钥
*/
private static final String SECRET = "my_secret";
/**
* 过期时间
**/
private static final long EXPIRATION = 1800L;//单位为秒
/**
* 生成用户token,设置token超时时间
*/
public static String createToken(User user) {
//过期时间
Date expireDate = new Date(System.currentTimeMillis() + EXPIRATION * 1000);
Map<String, Object> map = new HashMap<>();
map.put("alg", "HS256");
map.put("typ", "JWT");
String token = JWT.create()
.withHeader(map)// 添加头部
//可以将基本信息放到claims中
.withClaim("id", user.getId())//userId
.withClaim("userName", user.getUserName())//userName
.withClaim("password", user.getPassword())//password
.withExpiresAt(expireDate) //超时设置,设置过期的日期
.withIssuedAt(new Date()) //签发时间
.sign(Algorithm.HMAC256(SECRET)); //SECRET加密
return token;
}
/**
* 校验token并解析token
*/
public static Map<String, Claim> verifyToken(String token) {
DecodedJWT jwt = null;
try {
JWTVerifier verifier = JWT.require(Algorithm.HMAC256(SECRET)).build();
jwt = verifier.verify(token);
//decodedJWT.getClaim("属性").asString() ?获取负载中的属性值
} catch (Exception e) {
logger.error(e.getMessage());
logger.error("token解码异常");
//解码异常则抛出异常
return null;
}
return jwt.getClaims();
}
}
JWT过滤器
/**
* JWT过滤器，拦截 /secure的请求
* JWT过滤器中进行token的校验和判断，token不合法直接返回，合法则解密数据并把数据放到request中供后续使用。
*
* 为了使过滤器生效，需要在启动类添加注解@ServletComponentScan(basePackages = "com.zhaoyang.config")。
*/
@Slf4j
@WebFilter(filterName = "JwtFilter", urlPatterns = "/secure/*")
public class JwtFilter implements Filter
{
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
final HttpServletRequest request = (HttpServletRequest) req;
final HttpServletResponse response = (HttpServletResponse) res;
response.setCharacterEncoding("UTF-8");
//获取 header里的token
final String token = request.getHeader("authorization");
if ("OPTIONS".equals(request.getMethod())) {
response.setStatus(HttpServletResponse.SC_OK);
chain.doFilter(request, response);
}
// Except OPTIONS, other request should be checked by JWT
else {
if (token == null) {
response.getWriter().write("没有token！");
return;
}
Map<String, Claim> userData = JwtUtil.verifyToken(token);
if (userData == null) {
response.getWriter().write("token不合法！");
return;
}
Integer id = userData.get("id").asInt();
String userName = userData.get("userName").asString();
String password= userData.get("password").asString();
//拦截器 拿到用户信息，放到request中
request.setAttribute("id", id);
request.setAttribute("userName", userName);
request.setAttribute("password", password);
chain.doFilter(req, res);
}
}
@Override
public void destroy() {
}
}
登录Controller
/**
* 登录Controller
* LoginController进行登录操作，登录成功后生产token并返回。
*/
@Slf4j
@RestController
public class LoginController
{
static Map<Integer, User> userMap = new HashMap<>();
static {
//模拟数据库
User user1 = new User(1,"张三","123456");
userMap.put(1, user1);
User user2 = new User(2,"李四","123123");
userMap.put(2, user2);
}
/**
* 模拟用户 登录
*/
@RequestMapping("/login")
public String login(User user)
{
for (User dbUser : userMap.values()) {
if (dbUser.getUserName().equals(user.getUserName()) && dbUser.getPassword().equals(user.getPassword())) {
log.info("登录成功！生成token！");
String token = JwtUtil.createToken(dbUser);
return token;
}
}
return "";
}
}
携带jwt才能访问
/**
*需要登录后携带JWT才能访问
* SecureController中的请求会被JWT过滤器拦截，合法后才能访问。
?*/
@Slf4j
@RestController
public class SecureController
{
????/**
*查询 用户信息，登录后携带JWT才能访问
?????*/
????@RequestMapping("/secure/getUserInfo")
????public String login(HttpServletRequest request) {
????????Integer id = (Integer) request.getAttribute("id");
????????String userName = request.getAttribute("userName").toString();
????????String password= request.getAttribute("password").toString();
return "当前用户信息id=" + id + ",userName=" + userName+ ",password=" + password;
????}
}
启动类
@SpringBootApplication
@ServletComponentScan(basePackages = "com.zhaoyang.config")
public class SsmWebApplication {
public static void main(String[] args) {
SpringApplication.run(SsmWebApplication.class, args);
}
}
接口测试
测试分两步，首先访问登录接口，登录成功后获取token，然后拿着token在访问查询用户信息接口。
