JWT(JSON Web Token),为了在网络应用环境间传递声明而执行的一种基于JSON的开放标准。将用户信息加密到token中,服务器不保存任何用户信息,服务器通过保存的密钥验证token的正确性。
JWT由三部分构成,类似于如下:
eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJzdWIiOiJscyIsImV4cCI6MTYyNDU5Nzc5Nn0.4kwT1elZCb_k2D7AxbuFHM35VmBK4PcmLaqHhcHEq4_wVe8GVO8ODypGSKksTs-hraBopBCm2IC9EC2rO-GHng
第一部分为头部(header),承载两部分信息
{
"typ","JWT",
"alg","HS256"
}
使用Base64加密后
eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9
第二部分为payload(载荷),存放有效信息的地方,这些有效信息分为三部分:
其中,标准中注册的声明 (建议但不强制使用)包括如下几个部分 :
公共的声明部分:
公共的声明可以添加任何信息,一般添加用户的相关信息或其他业务需要的必要信息,但不建议添加铭感信息,因为在客户端可解密。
私有的声明部分:
私有的声明是提供者和消费者共同定义的声明,不建议存放敏感信息,因为base64是对称解密的,意味着该部分信息可以归类为明文信息。
第三部分为signature(签证)
var encodedString = base64UrlEncode(header) + '.' + base64UrlEncode(payload);
//密钥就是我们定义的secret,加密后得到签证
var signature = HMACSHA256(encodedString, '密钥');
<!--JWT-->
<dependency>
<groupId>io.jsonwebtoken</groupId>
<artifactId>jjwt</artifactId>
<version>0.7.0</version>
</dependency>
<dependency>
<groupId>com.auth0</groupId>
<artifactId>java-jwt</artifactId>
<version>3.4.0</version>
</dependency>
<!--StringUtils工具包-->
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.6</version>
</dependency>
<!--ConfigurationProperties出现异常-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
server:
port: 8888
spring:
jwt:
#过期时间
expireTime: 1800000
#加密密钥
secret: lsyyp5201314
#token返回头部
header: LOGINTOKEN
package org.best.util;
import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.TokenExpiredException;
import org.springframework.boot.context.properties.ConfigurationProperties;
import java.util.Date;
@ConfigurationProperties(prefix = "spring.jwt")
public class JWTUtils {
public static String header;
private static String secret;
private static String expireTime;
/**
* 生成token
* @param sub 用户唯一信息
* @return token
*/
public static String createToken(String sub){
return JWT
.create()
.withSubject(sub)
.withExpiresAt(new Date(System.currentTimeMillis()+Long.parseLong(expireTime)))
.sign(Algorithm.HMAC512(secret));
}
/**
* 根据token获取用户信息
* @param token
* @return 用户信息
*/
public static String validateToken(String token){
return JWT
.require(Algorithm.HMAC512(secret))
.build()
.verify(token)
.getSubject();
}
/**
* 检验Token是否需要刷新
* @param token
* @return
*/
public static boolean refreshToken(String token) {
Date expireDate = null;
try {
expireDate = JWT
.require(Algorithm.HMAC512(secret))
.build()
.verify(token)
.getExpiresAt();
} catch (TokenExpiredException e) {
return true;
}
return (expireDate.getTime()-System.currentTimeMillis())<0;
}
public void setHeader(String header) {
this.header = header;
}
public String getSecret() {
return secret;
}
public void setSecret(String secret) {
this.secret = secret;
}
public String getExpireTime() {
return expireTime;
}
public void setExpireTime(String expireTime) {
this.expireTime = expireTime;
}
}
package org.best.config;
import org.apache.commons.lang.StringUtils;
import org.best.common.TokenIsNullException;
import org.best.common.TokenValidateException;
import org.best.util.JWTUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
String logintoken = request.getHeader("LOGINTOKEN");
//如果token为空
if (StringUtils.isBlank(logintoken)){
throw new TokenIsNullException("请登录");
}
//校验Token
String sub = JWTUtils.validateToken(logintoken);
if (StringUtils.isBlank(sub)){
throw new TokenValidateException("token校验失败");
}
//更新token有效期(生产新token)
if (JWTUtils.refreshToken(logintoken)){
String token = JWTUtils.createToken(sub);
response.setHeader(JWTUtils.header,token);
}
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
}
}
package org.best.config;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class MyWebMvcConfig implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry
.addInterceptor(new LoginInterceptor())
.addPathPatterns("/find")
.excludePathPatterns("/login");
}
}
package org.best.common;
/**
* Token校验异常
*/
public class TokenValidateException extends RuntimeException {
public TokenValidateException() {
}
public TokenValidateException(String message) {
super(message);
}
}
package org.best.common;
/**
* Token为空异常
*/
public class TokenIsNullException extends RuntimeException{
public TokenIsNullException() {
}
public TokenIsNullException(String message) {
super(message);
}
}
package org.best.controller;
import org.best.pojo.User;
import org.best.util.JWTUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.servlet.http.HttpServletResponse;
@RestController
public class LoginController {
@GetMapping("/login")
public String login(User user, HttpServletResponse response){
//这里就不做数据库查询了
//根据用户id生成token
String token = JWTUtils.createToken(String.valueOf(user.getId()));
//将token存入HTTP响应头中
response.setHeader(JWTUtils.header,token);
return user.toString();
}
@GetMapping("/find")
public String find(){
return "success";
}
}
登录接口
我们来测试下find 接口 ,不带token会出现啥情况
带上token