Spring Boot集成JWT令牌报错：javax.xml.bind.DatatypeConverter缺失

按照教程搭建集成JWT令牌的Spring Boot应用，通过Postman发送POST请求、JSON格式传入用户名密码获取令牌时，触发500内部服务器错误，具体报错为java.lang.ClassNotFoundException: javax.xml.bind.DatatypeConverter。

报错堆栈信息 #

java.lang.ClassNotFoundException: javax.xml.bind.DatatypeConverter
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[na:na]
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) ~[na:na]
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ~[na:na]
    at io.jsonwebtoken.impl.Base64Codec.decode(Base64Codec.java:26) ~[jjwt-0.9.1.jar:0.9.1]
    at io.jsonwebtoken.impl.DefaultJwtBuilder.signWith(DefaultJwtBuilder.java:99) ~[jjwt-0.9.1.jar:0.9.1]
    at com.JavaInUseSpringSECURITY.JavaInUseSpringSECURITY.JWTTOKEN.JwtUtil.doGenerateToken(JwtUtil.java:49) ~[classes/:na]
    at com.JavaInUseSpringSECURITY.JavaInUseSpringSECURITY.JWTTOKEN.JwtUtil.generateToken(JwtUtil.java:43) ~[classes/:na]

JwtUtil类代码 #

@Service
public class JwtUtil {

    private String secret;
    private int jwtExpirationInMs;

    @Value("${jwt.secret}")
    public void setSecret(String secret) {
        this.secret = secret;
    }

    @Value("${jwt.jwtExpirationInMs}")
    public void setJwtExpirationInMs(int jwtExpirationInMs) {
        this.jwtExpirationInMs = jwtExpirationInMs;
    }

    // generate token for user
    public String generateToken(UserDetails userDetails) {
        Map<String, Object> claims = new HashMap<>();
        Collection<? extends GrantedAuthority> roles = userDetails.getAuthorities();
        if (roles.contains(new SimpleGrantedAuthority("ROLE_ADMIN"))) {
            claims.put("isAdmin", true);
        }
        if (roles.contains(new SimpleGrantedAuthority("ROLE_USER"))) {
            claims.put("isUser", true);
        }
        return doGenerateToken(claims, userDetails.getUsername());
    }


    private String doGenerateToken(Map<String, Object> claims, String subject) {

        return Jwts.builder().setClaims(claims).setSubject(subject)
.setIssuedAt(new Date(System.currentTimeMillis()))
                .setExpiration(new Date(System.currentTimeMillis() + jwtExpirationInMs)).signWith(SignatureAlgorithm.HS512, secret).compact();
    }

}

接口响应内容 #

{
    "timestamp": "2022-10-31T16:35:00.188+00:00",
    "status": 500,
    "error": "Internal Server Error",
    "path": "/authenticate"
}

解决方案 #

原因 #

你使用的JJWT版本（0.9.1）依赖javax.xml.bind.DatatypeConverter，但该类在Java 9及以上版本中已从JDK核心模块中移除，导致类找不到。

方法1：添加JAXB依赖 #

如果坚持使用JJWT 0.9.1，在Maven的pom.xml中加入以下依赖：

<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.3.1</version>
</dependency>
<dependency>
    <groupId>com.sun.xml.bind</groupId>
    <artifactId>jaxb-impl</artifactId>
    <version>2.3.1</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>com.sun.xml.bind</groupId>
    <artifactId>jaxb-core</artifactId>
    <version>2.3.0.1</version>
</dependency>
<dependency>
    <groupId>javax.activation</groupId>
    <artifactId>activation</artifactId>
    <version>1.1.1</version>
</dependency>

Gradle项目则在build.gradle中添加：

implementation 'javax.xml.bind:jaxb-api:2.3.1'
runtimeOnly 'com.sun.xml.bind:jaxb-impl:2.3.1'
implementation 'com.sun.xml.bind:jaxb-core:2.3.0.1'
implementation 'javax.activation:activation:1.1.1'

方法2：升级JJWT版本（推荐） #

JJWT 0.10.0及以上版本不再依赖JAXB，建议升级到最新稳定版。修改Maven依赖：

<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt-api</artifactId>
    <version>0.11.5</version>
</dependency>
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt-impl</artifactId>
    <version>0.11.5</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt-jackson</artifactId>
    <version>0.11.5</version>
    <scope>runtime</scope>
</dependency>

同时调整JwtUtil中的signWith方法（新版本API变化）：

// 修改doGenerateToken方法内的signWith代码
.signWith(SignatureAlgorithm.HS512, Keys.hmacShaKeyFor(secret.getBytes(StandardCharsets.UTF_8)))

需要导入以下类：

import io.jsonwebtoken.security.Keys;
import java.nio.charset.StandardCharsets;

内容的提问来源于stack exchange，提问作者Anxheloo