依赖：

        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>
        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>3.4.0</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.1</version>
        </dependency>

工具类代码:import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.springframework.core.io.ClassPathResource;
import org.springframework.security.rsa.crypto.KeyStoreKeyFactory;import java.security.KeyPair;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;/*** JWT工具类*/
public class JwtUtils {private static final Long expire = 1800000L;public static String generateJwt(Map<String, Object> claims) {return Jwts.builder().addClaims(claims).signWith(SignatureAlgorithm.RS256, keyPair().getPrivate()).setExpiration(new Date(System.currentTimeMillis() + expire)).compact();}public static KeyPair keyPair() {KeyStoreKeyFactory keyStoreKeyFactory = new KeyStoreKeyFactory(new ClassPathResource("jwt.jks"), "20211202".toCharArray());return keyStoreKeyFactory.getKeyPair("jwt", "20211202".toCharArray());}public static void main(String[] args) {Map<String, Object> map = new HashMap<>();map.put("id", 1);String jwt_token = JwtUtils.generateJwt(map);System.out.println("token:"+jwt_token);}
}

生成jwt.jks文件放到自己的项目里