Question

我正在浏览Scalatra 2.4的Scalatra "Handling JSON" tutorial，并且我得到了一个＆＃34; NoSuchMethodError＆＃34;：

Exception in thread "main" java.lang.NoSuchMethodError: org.scalatra.json.JacksonJsonSupport$class.initialize(Lorg/scalatra/json/JacksonJsonSupport;Ljava/lang/Object;)V
    at com.tutorial.FlowersController.initialize(FlowersController.scala:8)
    at com.tutorial.FlowersController.initialize(FlowersController.scala:8)
    at org.scalatra.ScalatraServlet$class.init(ScalatraServlet.scala:123)
    at com.tutorial.FlowersController.init(FlowersController.scala:8)
    at org.eclipse.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:595)
    at org.eclipse.jetty.servlet.ServletHolder.initialize(ServletHolder.java:385)
    at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:862)
    at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:300)
    at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1341)
    at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1334)
    at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:744)
    at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:497)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
    at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:60)
    at org.eclipse.jetty.server.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:154)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
    at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:60)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
    at org.eclipse.jetty.server.Server.start(Server.java:357)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
    at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:60)
    at org.eclipse.jetty.server.Server.doStart(Server.java:324)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.runner.Runner.run(Runner.java:509)
    at org.eclipse.jetty.runner.Runner.main(Runner.java:557)

我在JacksonJsonSupport＆＃34;中添加了＆＃34;以及＆＃34;受保护的隐式lazy val jsonFormats：Formats = DefaultFormats＆＃34;在控制器签名之后。我在顶部有两个导入，导入org.json4s。{DefaultFormats，Formats}并导入org.scalatra.json ._

为了完整起见，我的ScalatraBootstrap没有包装声明，如下所示：

import com.tutorial._
import org.scalatra._
import javax.servlet.ServletContext

class ScalatraBootstrap extends LifeCycle {
  override def init(context: ServletContext) {
    context.mount(new FlowersController, "/*")
  }
}

我添加了＆＃34; org.scalatra＆＃34; %%＆＃34; scalatra-json＆＃34; ％ScalatraVersion和＆＃34; org.json4s＆＃34; %%＆＃34; json4s-jackson＆＃34; ％＆＃34; 3.3.0＆＃34;，到build.scala并重新启动sbt。我错过了什么？

Answer 1

我使用了＃34; sbt clean＆＃34;。该教程建议只需重新启动sbt即可下载新的jar，并再次通过它，它工作正常，但我最初的尝试显然不太正确。我能想到的唯一区别是，我在Docker容器中运行初始尝试，也许某些东西并不完美。

JacksonJsonSupport trait导致NoSuchMethodError初始化（）

1 个答案: