새 GSCService 인스턴스 만들기 런타임 오류

Question

간단한 앱에서 GCS _google 클라우드 저장소로 GAE 앱을 연결합니다.

다음 GCSTestServlet 서블릿을 사용하여 새 GSCService 인스턴스 인 을 만들려고합니다. 그러나 다음 실행 시간 오류가 있습니다.

java.lang.NoClassDefFoundError: com/google/appengine/tools/cloudstorage/RetryParams 

아무도 내가이 오류를 풀 수 있도록 도와 주길 바랍니다. 덕분에 .

여기에 오류에 대한 모든 세부 정보가 나와 있습니다.

플랫폼은 내가

• elcipse 4.2.1
• 자바 jdk1를 사용합니다. 7.0_09
• appengine-java-sdk-1.8.

가져 오기 JAR 파일.

• 에서 appengine-GCS-클라이언트 0.3.jar
• 나는 다음과 같은 오류 메시지가

  package ahmed.com; 
  
      import java.io.IOException; 
      import javax.servlet.http.*; 
  
      import com.google.appengine.tools.cloudstorage.GcsService; 
      import com.google.appengine.tools.cloudstorage.GcsServiceFactory; 
      import com.google.appengine.tools.cloudstorage.RetryParams; 
  
      @SuppressWarnings("serial") 
      public class GCSTestServlet extends HttpServlet { 
       //the problem appear by just try to create GcsService 
       private final GcsService gcsService = 
         GcsServiceFactory.createGcsService(RetryParams.getDefaultInstance()); 
       public void doGet(HttpServletRequest req, HttpServletResponse resp) 
         throws IOException { 
        resp.setContentType("text/plain"); 
        resp.getWriter().println("Hello, world"); 
       } 
      } 
  

  구아바 - 14.0.1.jar

GCSTestServlet 서블릿.

참고 "/ gcstest"는 이전 서블릿의 URL입니다.

Problem accessing /gcstest. Reason: 

    com/google/appengine/tools/cloudstorage/RetryParams 

Caused by: 

java.lang.NoClassDefFoundError: com/google/appengine/tools/cloudstorage/RetryParams 
    at ahmed.com.GCSTestServlet.<init>(GCSTestServlet.java:14) 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) 
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) 
    at java.lang.reflect.Constructor.newInstance(Constructor.java:525) 
    at java.lang.Class.newInstance0(Class.java:372) 
    at java.lang.Class.newInstance(Class.java:325) 
    at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153) 
    at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:428) 
    at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339) 
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166) 
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:368) 
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:351) 
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388) 
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) 
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) 
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) 
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418) 
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:97) 
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) 
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:485) 
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) 
    at org.mortbay.jetty.Server.handle(Server.java:326) 
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542) 
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923) 
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547) 
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212) 
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) 
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409) 
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582) 
Caused by: java.lang.ClassNotFoundException: com.google.appengine.tools.cloudstorage.RetryParams 
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366) 
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354) 
    at java.lang.ClassLoader.loadClass(ClassLoader.java:423) 
    at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:215) 
    at java.lang.ClassLoader.loadClass(ClassLoader.java:356) 
    ... 45 more 

Caused by: 

java.lang.ClassNotFoundException: com.google.appengine.tools.cloudstorage.RetryParams 
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366) 
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354) 
    at java.lang.ClassLoader.loadClass(ClassLoader.java:423) 
    at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:215) 
    at java.lang.ClassLoader.loadClass(ClassLoader.java:356) 
    at ahmed.com.GCSTestServlet.<init>(GCSTestServlet.java:14) 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) 
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) 
    at java.lang.reflect.Constructor.newInstance(Constructor.java:525) 
    at java.lang.Class.newInstance0(Class.java:372) 
    at java.lang.Class.newInstance(Class.java:325) 
    at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153) 
    at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:428) 
    at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339) 
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166) 
    at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:368) 
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:351) 
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116) 
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) 
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388) 
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) 
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) 
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) 
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418) 
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:97) 
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) 
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:485) 
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) 
    at org.mortbay.jetty.Server.handle(Server.java:326) 
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542) 
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923) 
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547) 
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212) 
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) 
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409) 
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582) 

Answer 1

마지막으로 오류의 원인을 찾아 해결했습니다.

문제는 Project에 JAR 파일을 가져 왔지만 (war> WEB-INF> lib) 폴더에 복사하지 않았기 때문에 컴파일 할 때 응용 프로그램이 클래스를 발견했지만 런타임에 응용 프로그램이 클래스를 찾을 수 없으므로 다음 오류 메시지가 나타납니다.

java.lang.NoClassDefFoundError: com/google/appengine/tools/cloudstorage/RetryParams 

Answer 2

jar 파일의 이전 버전이나 새 버전을 사용하고 있다고 생각합니다. 당신은

에서 appengine-자바 SDK-1.8.jar /에서 appengine-GCS-클라이언트 0.3.jar/구아바-14.0.1.jar이

컴파일에로드되어 있는지 확인해야합니다 시간 및 응용 프로그램의 런타임에로드 된 동일한 버전은 런타임에로드 된 jar 파일이 응용 프로그램의 빌드 경로에서 사용하는 것보다 오래되었을 가능성이 높습니다.

나는 전에도 같은 문제에 직면했다!