[JWT][JJWT]函数compact()非常慢

Question

我使用lib JJWT 0.9.0来生成Token。如何更快地运行函数compact()，或者如何更快地生成令牌？我使用JDK7。

我的代码：

public String createJWT(String id, String issuer, String subject, List<T> authories, String loginUserData,
            long ttlMillis) {
        //The JWT signature algorithm we will be using to sign the token
        long startTime = System.currentTimeMillis();
        LOGGER.info("createJWT id=" + id + ";issuer=" + ";subject=" + subject);
        SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.HS512;

        long nowMillis = System.currentTimeMillis();
        Date now = new Date(nowMillis);

        //We will sign our JWT with our ApiKey secret
        byte[] apiKeySecretBytes = DatatypeConverter.parseBase64Binary(ApiSecretKey.getSecretKey());
        Key signingKey = new SecretKeySpec(apiKeySecretBytes, signatureAlgorithm.getJcaName());

        //Let's set the JWT Claims
        JwtBuilder builder = Jwts.builder().setId(id).setIssuedAt(now).setSubject(subject)
                .setIssuer(issuer);
        if (!CheckObjectUtils.isNullOrEmpty(authories)) {
            builder.claim(AUTHORITIES_KEY, authories);
        }
        if (!CheckObjectUtils.isNullOrEmpty(loginUserData)) {
            builder.claim(LOGIN_USER_DATA_KEY, loginUserData);
        }

        builder.signWith(signatureAlgorithm, signingKey);

        //if it has been specified, let's add the expiration
        if (ttlMillis >= 0) {
            long expMillis = nowMillis + ttlMillis;
            Date exp = new Date(expMillis);
            builder.setExpiration(exp);
        }
        LOGGER.info("createJWT process id=" + id + ";issuer=" + ";subject=" + subject + ";time(ms)="
                + (System.currentTimeMillis() - startTime));
        //Builds the JWT and serializes it to a compact, URL-safe string        
        String token = builder.compact();
        LOGGER.info("createJWT end id=" + id + ";issuer=" + ";subject=" + subject + ";time(ms)="
                + (System.currentTimeMillis() - startTime));
        return token;
    }

JsonWebTokenRestApi<Long> jwtApi = new JsonWebTokenRestApiFactory(
                JsonWebTokenRestApiFactory.JWT_JJWT).getJsonWebTokenByType();
        String jwt = jwtApi.createJWT(null, null, "vinhhc_vsc", null, null, 18000);

我的控制台日志：

createJWT id=null;issuer=;subject=vinhhc_vsc
createJWT process id=null;issuer=;subject=vinhhc_vsc;time(ms)=151
createJWT end id=null;issuer=;subject=vinhhc_vsc;time(ms)=664

谢谢!

Answer 1

这是正常的JVM JIT行为-由于JIT优化，初始运行缓慢，随后运行优化/快速是完全正常的。只需在循环中运行compact()调用，看看会发生什么。

以下是使用最“昂贵”的密钥算法HMAC-SHA-512重写的测试作为证明：

import io.jsonwebtoken.JwtBuilder;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import io.jsonwebtoken.lang.Collections;
import io.jsonwebtoken.lang.Strings;
import io.jsonwebtoken.security.Keys;

import java.security.Key;
import java.util.Date;
import java.util.List;
import java.util.UUID;

public class Test {

    private static final Key signingKey = Keys.secretKeyFor(SignatureAlgorithm.HS512);

    private static <T> String createJWT(String id, String issuer, String subject, List<T> authories, String loginUserData,
                                       long ttlMillis) {
        //The JWT signature algorithm we will be using to sign the token
        long startTime = System.currentTimeMillis();
        System.out.println("createJWT id=" + id + ";issuer=" + ";subject=" + subject);
        SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.HS512;

        long nowMillis = System.currentTimeMillis();
        Date now = new Date(nowMillis);

        //Let's set the JWT Claims
        JwtBuilder builder = Jwts.builder().setId(id).setIssuedAt(now).setSubject(subject)
                .setIssuer(issuer);
        if (!Collections.isEmpty(authories)) {
            builder.claim("authorities", authories);
        }
        if (!Strings.hasText(loginUserData)) {
            builder.claim("loginUserData", loginUserData);
        }

        builder.signWith(signingKey);

        //if it has been specified, let's add the expiration
        if (ttlMillis >= 0) {
            long expMillis = nowMillis + ttlMillis;
            Date exp = new Date(expMillis);
            builder.setExpiration(exp);
        }
        System.out.println("createJWT process id=" + id + ";issuer=" + ";subject=" + subject + ";time(ms)="
                + (System.currentTimeMillis() - startTime));
        //Builds the JWT and serializes it to a compact, URL-safe string
        String token = builder.compact();
        System.out.println("createJWT end id=" + id + ";issuer=" + ";subject=" + subject + ";time(ms)="
                + (System.currentTimeMillis() - startTime));
        return token;
    }

    public static void main(String[] args) {
        for( int i = 0; i < 10; i++) {
            createJWT(UUID.randomUUID().toString(), "issuer", "subject", null, "random user data", 1000);
        }
    }
}

以下是循环的输出：

createJWT id=983edbec-49f9-4754-9836-bae85c6c26e8;issuer=;subject=subject
createJWT process id=983edbec-49f9-4754-9836-bae85c6c26e8;issuer=;subject=subject;time(ms)=19
createJWT end id=983edbec-49f9-4754-9836-bae85c6c26e8;issuer=;subject=subject;time(ms)=319
createJWT id=ee8fa433-d032-4258-80e8-21f5fa54904c;issuer=;subject=subject
createJWT process id=ee8fa433-d032-4258-80e8-21f5fa54904c;issuer=;subject=subject;time(ms)=0
createJWT end id=ee8fa433-d032-4258-80e8-21f5fa54904c;issuer=;subject=subject;time(ms)=1
createJWT id=b8343d70-39e5-41fd-99e0-0046a0dcdb3c;issuer=;subject=subject
createJWT process id=b8343d70-39e5-41fd-99e0-0046a0dcdb3c;issuer=;subject=subject;time(ms)=0
createJWT end id=b8343d70-39e5-41fd-99e0-0046a0dcdb3c;issuer=;subject=subject;time(ms)=0
createJWT id=a2a81bfc-1bfd-42f8-81e3-dd27ca0bc343;issuer=;subject=subject
createJWT process id=a2a81bfc-1bfd-42f8-81e3-dd27ca0bc343;issuer=;subject=subject;time(ms)=0
createJWT end id=a2a81bfc-1bfd-42f8-81e3-dd27ca0bc343;issuer=;subject=subject;time(ms)=0
createJWT id=4236c531-d370-45d6-98cb-532b863d45af;issuer=;subject=subject
createJWT process id=4236c531-d370-45d6-98cb-532b863d45af;issuer=;subject=subject;time(ms)=0
createJWT end id=4236c531-d370-45d6-98cb-532b863d45af;issuer=;subject=subject;time(ms)=1
createJWT id=c3979b5c-2840-48bd-b72d-1e5d3776916b;issuer=;subject=subject
createJWT process id=c3979b5c-2840-48bd-b72d-1e5d3776916b;issuer=;subject=subject;time(ms)=0
createJWT end id=c3979b5c-2840-48bd-b72d-1e5d3776916b;issuer=;subject=subject;time(ms)=0
createJWT id=155e6ac6-da45-402b-a7a8-e98b358a3525;issuer=;subject=subject
createJWT process id=155e6ac6-da45-402b-a7a8-e98b358a3525;issuer=;subject=subject;time(ms)=0
createJWT end id=155e6ac6-da45-402b-a7a8-e98b358a3525;issuer=;subject=subject;time(ms)=1
createJWT id=f1cdc87c-2054-4ff5-bb5c-4b47384a1285;issuer=;subject=subject
createJWT process id=f1cdc87c-2054-4ff5-bb5c-4b47384a1285;issuer=;subject=subject;time(ms)=0
createJWT end id=f1cdc87c-2054-4ff5-bb5c-4b47384a1285;issuer=;subject=subject;time(ms)=0
createJWT id=0303f53f-9b9a-4e7c-99c6-788dbb883ce2;issuer=;subject=subject
createJWT process id=0303f53f-9b9a-4e7c-99c6-788dbb883ce2;issuer=;subject=subject;time(ms)=0
createJWT end id=0303f53f-9b9a-4e7c-99c6-788dbb883ce2;issuer=;subject=subject;time(ms)=1
createJWT id=701d08c1-cfcf-4f20-9270-5b1800d9a7e0;issuer=;subject=subject
createJWT process id=701d08c1-cfcf-4f20-9270-5b1800d9a7e0;issuer=;subject=subject;time(ms)=0
createJWT end id=701d08c1-cfcf-4f20-9270-5b1800d9a7e0;issuer=;subject=subject;time(ms)=0

请注意，第一次(也只是第一次)运行的开销很大(公平地说，它只有319毫秒)，而由于JIT优化，所有其他的运行都非常快。

大多数后续的compact()调用通常只有几微秒(甚至不到1毫秒)！