针对Java REST应用程序的HTTP状态500

Question

尝试访问我的EC2服务器上的.wadl文件（使用Elastic Beanstalk进行部署）时，我一直收到此错误。任何想法是什么意思/如何解决它？

类型异常报告

消息

描述服务器遇到一个内部错误（）阻止其完成此请求。

例外

javax.servlet.ServletException: Servlet.init() for servlet ServletAdaptor threw exception 
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:680) 
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:928) 
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987) 
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:539) 
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:298) 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) 
java.lang.Thread.run(Thread.java:636) 

root cause 

java.lang.NoClassDefFoundError: javax/persistence/criteria/Expression 
java.lang.Class.getDeclaredConstructors0(Native Method) 
java.lang.Class.privateGetDeclaredConstructors(Class.java:2406) 
java.lang.Class.getConstructors(Class.java:1476) 
com.sun.jersey.server.impl.modelapi.annotation.IntrospectionModeller.createResource(IntrospectionModeller.java:111) 
com.sun.jersey.server.impl.application.WebApplicationImpl.getAbstractResource(WebApplicationImpl.java:745) 
com.sun.jersey.server.impl.application.WebApplicationImpl.createAbstractResourceModelStructures(WebApplicationImpl.java:1522) 
com.sun.jersey.server.impl.application.WebApplicationImpl._initiate(WebApplicationImpl.java:1295) 
com.sun.jersey.server.impl.application.WebApplicationImpl.access$700(WebApplicationImpl.java:169) 
com.sun.jersey.server.impl.application.WebApplicationImpl$13.f(WebApplicationImpl.java:775) 
com.sun.jersey.server.impl.application.WebApplicationImpl$13.f(WebApplicationImpl.java:771) 
com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:193) 
com.sun.jersey.server.impl.application.WebApplicationImpl.initiate(WebApplicationImpl.java:771) 
com.sun.jersey.server.impl.application.WebApplicationImpl.initiate(WebApplicationImpl.java:766) 
com.sun.jersey.spi.container.servlet.ServletContainer.initiate(ServletContainer.java:488) 
com.sun.jersey.spi.container.servlet.ServletContainer$InternalWebComponent.initiate(ServletContainer.java:318) 
com.sun.jersey.spi.container.servlet.WebComponent.load(WebComponent.java:609) 
com.sun.jersey.spi.container.servlet.WebComponent.init(WebComponent.java:210) 
com.sun.jersey.spi.container.servlet.ServletContainer.init(ServletContainer.java:373) 
com.sun.jersey.spi.container.servlet.ServletContainer.init(ServletContainer.java:556) 
javax.servlet.GenericServlet.init(GenericServlet.java:160) 
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:680) 
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:928) 
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987) 
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:539) 
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:298) 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) 
java.lang.Thread.run(Thread.java:636) 
root cause 

java.lang.ClassNotFoundException: javax.persistence.criteria.Expression 
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1688) 
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1533) 
java.lang.Class.getDeclaredConstructors0(Native Method) 
java.lang.Class.privateGetDeclaredConstructors(Class.java:2406) 
java.lang.Class.getConstructors(Class.java:1476) 
com.sun.jersey.server.impl.modelapi.annotation.IntrospectionModeller.createResource(IntrospectionModeller.java:111) 
com.sun.jersey.server.impl.application.WebApplicationImpl.getAbstractResource(WebApplicationImpl.java:745) 
com.sun.jersey.server.impl.application.WebApplicationImpl.createAbstractResourceModelStructures(WebApplicationImpl.java:1522) 
com.sun.jersey.server.impl.application.WebApplicationImpl._initiate(WebApplicationImpl.java:1295) 
com.sun.jersey.server.impl.application.WebApplicationImpl.access$700(WebApplicationImpl.java:169) 
com.sun.jersey.server.impl.application.WebApplicationImpl$13.f(WebApplicationImpl.java:775) 
com.sun.jersey.server.impl.application.WebApplicationImpl$13.f(WebApplicationImpl.java:771) 
com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:193) 
com.sun.jersey.server.impl.application.WebApplicationImpl.initiate(WebApplicationImpl.java:771) 
com.sun.jersey.server.impl.application.WebApplicationImpl.initiate(WebApplicationImpl.java:766) 
com.sun.jersey.spi.container.servlet.ServletContainer.initiate(ServletContainer.java:488) 
    com.sun.jersey.spi.container.servlet.ServletContainer$InternalWebComponent.initiate(ServletContainer.java:318) 
com.sun.jersey.spi.container.servlet.WebComponent.load(WebComponent.java:609) 
com.sun.jersey.spi.container.servlet.WebComponent.init(WebComponent.java:210) 
com.sun.jersey.spi.container.servlet.ServletContainer.init(ServletContainer.java:373) 
com.sun.jersey.spi.container.servlet.ServletContainer.init(ServletContainer.java:556) 
javax.servlet.GenericServlet.init(GenericServlet.java:160) 
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) 
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:680) 
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:928) 
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) 
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987) 
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:539) 
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:298) 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) 
java.lang.Thread.run(Thread.java:636) 

注根源的完整堆栈跟踪中的Apache Tomcat/7.0.23日志是可用的。

Answer 1

当服务器出现某种错误时，通常会引发错误代码500，
就像未捕获的异常一样。
我提到的这个例子，因为这是你的情况，查看日志的这部分：

java.lang.ClassNotFoundException: javax.persistence.criteria.Expression org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1688) org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:153 

你可能在你的代码中使用JPA，但JPA罐子是不是在你的WEB-INF/lib目录目录。
请检查您的web应用程序结构，修复和重新部署。