Minha Dúvida é sobre WebServices

Quando você rodou o comando

ant jetty.run

deu alguma mensagem de erro no log?

Olá, boa tarde,

Eu fiz o que me recomendou, inseri ant jetty.run e deu erro de servidor agora, deu erro HTTP ERROR 503.

Oi Cleiton

Envia o log do jetty aqui por favor

org.scannotation.AnnotationDB.scanClass(AnnotationDB.java:311)
    [jetty]     at org.scannotation.AnnotationDB.scanArchives(AnnotationDB.java:294)
    [jetty]     at br.com.caelum.vraptor.scan.ScannotationComponentScanner.scanWebInfClasses(ScannotationComponentScanner.java:71)
    [jetty]     ... 40 more
    [jetty] 2020-09-06 11:48:28.345::WARN:  Failed startup of context org.mortbay.jetty.webapp.WebAppContext@252f626c{/,C:\Users\User\desktop\leiloes-ws\leiloes\src\main\webapp}
    [jetty] br.com.caelum.vraptor.scan.ScannerException: Could not scan WEB-INF/classes
    [jetty]     at br.com.caelum.vraptor.scan.ScannotationComponentScanner.scanWebInfClasses(ScannotationComponentScanner.java:74)
    [jetty]     at br.com.caelum.vraptor.scan.ScannotationComponentScanner.scan(ScannotationComponentScanner.java:57)
    [jetty]     at br.com.caelum.vraptor.scan.WebAppBootstrapFactory.create(WebAppBootstrapFactory.java:65)
    [jetty]     at br.com.caelum.vraptor.ioc.spring.SpringProvider.start(SpringProvider.java:83)
    [jetty]     at br.com.caelum.vraptor.VRaptor.init(VRaptor.java:110)
    [jetty]     at br.com.caelum.vraptor.VRaptor.init(VRaptor.java:103)
    [jetty]     at org.mortbay.jetty.servlet.FilterHolder.doStart(FilterHolder.java:97)
    [jetty]     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
    [jetty]     at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:620)
    [jetty]     at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
    [jetty]     at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1234)
    [jetty]     at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
    [jetty]     at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:460)
    [jetty]     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
    [jetty]     at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
    [jetty]     at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156)
    [jetty]     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
    [jetty]     at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
    [jetty]     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
    [jetty]     at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
    [jetty]     at org.mortbay.jetty.Server.doStart(Server.java:222)
    [jetty]     at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
    [jetty]     at org.mortbay.jetty.ant.ServerProxyImpl.start(ServerProxyImpl.java:209)
    [jetty]     at org.mortbay.jetty.ant.JettyRunTask.execute(JettyRunTask.java:204)
    [jetty]     at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:293)
    [jetty]     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    [jetty]     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    [jetty]     at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    [jetty]     at java.base/java.lang.reflect.Method.invoke(Method.java:564)
    [jetty]     at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
    [jetty]     at org.apache.tools.ant.Task.perform(Task.java:352)
    [jetty]     at org.apache.tools.ant.Target.execute(Target.java:437)
    [jetty]     at org.apache.tools.ant.Target.performTasks(Target.java:458)
    [jetty]     at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1406)
    [jetty]     at org.apache.tools.ant.Project.executeTarget(Project.java:1377)
    [jetty]     at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
    [jetty]     at org.apache.tools.ant.Project.executeTargets(Project.java:1261)
    [jetty]     at org.apache.tools.ant.Main.runBuild(Main.java:857)
    [jetty]     at org.apache.tools.ant.Main.startAnt(Main.java:236)
    [jetty]     at org.apache.tools.ant.launch.Launcher.run(Launcher.java:287)
    [jetty]     at org.apache.tools.ant.launch.Launcher.main(Launcher.java:112)
    [jetty] Caused by: java.io.IOException: invalid constant type: 18
    [jetty]     a

Estou a mesma dificuldade

HTTP ERROR: 503 SERVICE_UNAVAILABLE RequestURI=/usuarios

[jetty] Caused by: java.io.IOException: invalid constant type: 18

pelo erro parece que está sendo usado algum recurso do Java 8 no projeto Java 7. Minha sugestão seria usar o JDK 7 e não usar nenhum recurso mais novo da linguagem, esse curso é bem antigo