真正解决方案：java.lang.NoClassDefFoundError: javax/xml/bind/DatatypeConverter

环境如下:  JDK11,IDEA2020.3,springboot 2.4.5

错误如下:在实行jwt生成token的时候爆出

Caused by: java.lang.NoClassDefFoundError: javax/xml/bind/DatatypeConverter
    at io.jsonwebtoken.impl.Base64Codec.decode(Base64Codec.java:26)
    at io.jsonwebtoken.impl.DefaultJwtBuilder.signWith(DefaultJwtBuilder.java:106)
    at com.jouyo.commonutils.JwtUtils.getJwtToken(JwtUtils.java:37)
    at com.jouyo.educenter.service.impl.UcenterMemberServiceImpl.login(UcenterMemberServiceImpl.java:59)
    at com.jouyo.educenter.service.impl.UcenterMemberServiceImpl$$FastClassBySpringCGLIB$$e17e0e6e.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:687) at com.jouyo.educenter.service.impl.UcenterMemberServiceImpl$$EnhancerBySpringCGLIB$$6aba871b.login(<generated>) at com.jouyo.educenter.controller.UcenterMemberController.loginUser(UcenterMemberController.java:39) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ... 39 more Caused by: java.lang.ClassNotFoundException: javax.xml.bind.DatatypeConverter at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ... 59 more

故障原因:

 JAXB API是java EE 的API，因此在java SE 9.0 中不再包含这个 Jar 包。 java 9 中引入了模块的概念，默认情况下，Java SE中将不再包含java EE 的Jar包 而在 java 6/7 / 8 时关于这个API 都是捆绑在一起的 

解决问题1:

降低JDK 版本到 JDK 8

解决问题2:手动加入这些依赖Jar包

<dependency>
        <groupId>javax.xml.bind</groupId>
        <artifactId>jaxb-api</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-impl</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-core</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>javax.activation</groupId>
        <artifactId>activation</artifactId>
        <version>1.1.1</version>
    </dependency>