JWT Token实现方法及步骤详解

 <dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-jwt</artifactId>
    <version>${spring-security-jwt.version}</version>
 </dependency>

 /**
 * 构建 jwt payload
 *
 * @author Felordcn
 * @since 11:27 2019/10/25
 **/
 public class JwtPayloadBuilder {

   private Map<String, String> payload = new HashMap<>();
   /**
   * 附加的属性
   */
   private Map<String, String> additional;
   /**
   * jwt签发者
   **/
   private String iss;
   /**
   * jwt所面向的用户
   **/
   private String sub;
   /**
   * 接收jwt的一方
   **/
   private String aud;
   /**
   * jwt的过期时间，这个过期时间必须要大于签发时间
   **/
   private LocalDateTime exp;
   /**
   * jwt的签发时间
   **/
   private LocalDateTime iat = LocalDateTime.now();
   /**
   * 权限集
   */
   private Set<String> roles = new HashSet<>();
   /**
   * jwt的唯一身份标识，主要用来作为一次性token,从而回避重放***
   **/
   private String jti = IdUtil.simpleUUID();

   public JwtPayloadBuilder iss(String iss) {
     this.iss = iss;
     return this;
   }

   public JwtPayloadBuilder sub(String sub) {
     this.sub = sub;
     return this;
   }

   public JwtPayloadBuilder aud(String aud) {
     this.aud = aud;
     return this;
   }

   public JwtPayloadBuilder roles(Set<String> roles) {
     this.roles = roles;
     return this;
   }

   public JwtPayloadBuilder expDays(int days) {
     Assert.isTrue(days > 0, "jwt expireDate must after now");
     this.exp = this.iat.plusDays(days);
     return this;
   }

   public JwtPayloadBuilder additional(Map<String, String> additional) {
     this.additional = additional;
     return this;
   }

   public String builder() {
     payload.put("iss", this.iss);
     payload.put("sub", this.sub);
     payload.put("aud", this.aud);
     payload.put("exp", this.exp.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
     payload.put("iat", this.iat.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
     payload.put("jti", this.jti);

     if (!CollectionUtils.isEmpty(additional)) {
       payload.putAll(additional);
     }
     payload.put("roles", JSONUtil.toJsonStr(this.roles));
     return JSONUtil.toJsonStr(JSONUtil.parse(payload));

   }

 }

```java
 package cn.felord.spring.security.jwt;

 import org.springframework.core.io.ClassPathResource;

 import java.security.KeyFactory;
 import java.security.KeyPair;
 import java.security.KeyStore;
 import java.security.PublicKey;
 import java.security.interfaces.RSAPrivateCrtKey;
 import java.security.spec.RSAPublicKeySpec;

 /**
 * KeyPairFactory
 *
 * @author Felordcn
 * @since 13:41 2019/10/25
 **/
 class KeyPairFactory {

   private KeyStore store;

   private final Object lock = new Object();

   /**
   * 获取公私钥.
   *
   * @param keyPath jks 文件在 resources 下的classpath
   * @param keyAlias keytool 生成的 -alias 值 felordcn
   * @param keyPass keytool 生成的 -keypass 值 felordcn
   * @return the key pair 公私钥对
   */
  KeyPair create(String keyPath, String keyAlias, String keyPass) {
     ClassPathResource resource = new ClassPathResource(keyPath);
     char[] pem = keyPass.toCharArray();
     try {
       synchronized (lock) {
         if (store == null) {
           synchronized (lock) {
             store = KeyStore.getInstance("jks");
             store.load(resource.getInputStream(), pem);
           }
         }
       }
       RSAPrivateCrtKey key = (RSAPrivateCrtKey) store.getKey(keyAlias, pem);
       RSAPublicKeySpec spec = new RSAPublicKeySpec(key.getModulus(), key.getPublicExponent());
       PublicKey publicKey = KeyFactory.getInstance("RSA").generatePublic(spec);
       return new KeyPair(publicKey, key);
     } catch (Exception e) {
       throw new IllegalStateException("Cannot load keys from store: " + resource, e);
     }

   }
 }

   private String jwtToken(String aud, int exp, Set<String> roles, Map<String, String> additional) {
     String payload = jwtPayloadBuilder
         .iss(jwtProperties.getIss())
         .sub(jwtProperties.getSub())
         .aud(aud)
         .additional(additional)
         .roles(roles)
         .expDays(exp)
         .builder();
     RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

     RsaSigner signer = new RsaSigner(privateKey);
     return JwtHelper.encode(payload, signer).getEncoded();
   }

   public JwtTokenPair jwtTokenPair(String aud, Set<String> roles, Map<String, String> additional) {
     String accessToken = jwtToken(aud, jwtProperties.getAccessExpDays(), roles, additional);
     String refreshToken = jwtToken(aud, jwtProperties.getRefreshExpDays(), roles, additional);

     JwtTokenPair jwtTokenPair = new JwtTokenPair();
     jwtTokenPair.setAccessToken(accessToken);
     jwtTokenPair.setRefreshToken(refreshToken);
     // 放入缓存
     jwtTokenStorage.put(jwtTokenPair, aud);
     return jwtTokenPair;
   }

   /**
    * 解码 并校验签名 过期不予解析
    *
    * @param jwtToken the jwt token
    * @return the jwt claims
    */
   public JSONObject decodeAndVerify(String jwtToken) {
     Assert.hasText(jwtToken, "jwt token must not be bank");
     RSAPublicKey rsaPublicKey = (RSAPublicKey) this.keyPair.getPublic();
     SignatureVerifier rsaVerifier = new RsaVerifier(rsaPublicKey);
     Jwt jwt = JwtHelper.decodeAndVerify(jwtToken, rsaVerifier);
     String claims = jwt.getClaims();
     JSONObject jsonObject = JSONUtil.parseObj(claims);
     String exp = jsonObject.getStr(JWT_EXP_KEY);
     // 是否过期
     if (isExpired(exp)) {
       throw new IllegalStateException("jwt token is expired");
     }
     return jsonObject;
   }

 /**
 * Jwt 在 springboot application.yml 中的配置文件
 *
 * @author Felordcn
 * @since 15 :06 2019/10/25
 */
 @Data
 @ConfigurationProperties(prefix=JWT_PREFIX)
 public class JwtProperties {
   static final String JWT_PREFIX= "jwt.config";
   /**
   * 是否可用
   */
   private boolean enabled;
   /**
   * jks 路径
   */
   private String keyLocation;
   /**
   * key alias
   */
   private String keyAlias;
   /**
   * key store pass
   */
   private String keyPass;
   /**
   * jwt签发者
   **/
   private String iss;
   /**
   * jwt所面向的用户
   **/
   private String sub;
   /**
   * access jwt token 有效天数
   */
   private int accessExpDays;
   /**
   * refresh jwt token 有效天数
   */
   private int refreshExpDays;
 }

 /**
 * JwtConfiguration
 *
 * @author Felordcn
 * @since 16 :54 2019/10/25
 */
 @EnableConfigurationProperties(JwtProperties.class)
 @ConditionalOnProperty(prefix = "jwt.config",name = "enabled")
 @Configuration
 public class JwtConfiguration {

   /**
   * Jwt token storage .
   *
   * @return the jwt token storage
   */
   @Bean
   public JwtTokenStorage jwtTokenStorage() {
     return new JwtTokenCacheStorage();
   }

   /**
   * Jwt token generator.
   *
   * @param jwtTokenStorage the jwt token storage
   * @param jwtProperties  the jwt properties
   * @return the jwt token generator
   */
   @Bean
   public JwtTokenGenerator jwtTokenGenerator(JwtTokenStorage jwtTokenStorage, JwtProperties jwtProperties) {
     return new JwtTokenGenerator(jwtTokenStorage, jwtProperties);
   }

 }