2012-01-12 100 views
2

我希望你能帮助我: 我有一个用Eclipse创建的WebProject作为动态Web项目,运行在Glassfish3服务器上。我使用EJB 3.0创建一个实现我的业务逻辑的无状态的外墙(@Stateless注释):EJB3无状态Bean在REST-WebService中始终为空(GlassFish3,EJB3,无状态Bean)

@Stateless 
public class Facade { 

public void test(){  
System.out.println("test hat geklappt!!"); 
} 
} 

另外我使用的是RESTRessource提供使用我的EJB与(@EJB批注我的REST WS )业务逻辑:

@RequestScoped 
@Path("/prescriptions") 
public class Ressource { 

    @EJB 
    private Facade facade; 

    public Ressource() { 
     super(); 
    } 

    @GET 
    @Path("/user/{userid}") 
    @Produces(MediaType.APPLICATION_JSON) 
    public void getUser(@PathParam("userid") String userid) { 

     facade.test(); 

    } 

} 

虽然我可以进入REST WS并调用它,我的EJB总是空,我无法找到一个原因。

我真的很感激,如果你能帮助我。如果你需要更多关于代码的信息或者只是问一些问题。

由于提前, 弗洛里安

PS:我总是得到下面的错误在我的日志:

INFO: Portable JNDI names for EJB Facade : [java:global/TestProject/Facade,java:global/TestProject/Facade!webservices.Facade] 
INFO: Portable JNDI names for EJB Facade : [java:global/TestProject/Facade, java:global/TestProject/Facade!webservices.Facade] 
INFO: Scanning for root resource and provider classes in the packages: 
webservices 
INFO: Root resource classes found: 
class webservices.Ressource 
INFO: No provider classes found. 
INFO: Initiating Jersey application, version 'Jersey: 1.5 01/14/2011 12:36 PM' 

SCHWERWIEGEND: The RuntimeException could not be mapped to a response, re-throwing to the HTTP container  
java.lang.NullPointerException 

at webservices.Ressource.getUser(Ressource.java:40) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
at java.lang.reflect.Method.invoke(Method.java:597) 
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$VoidOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:150) 
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:70) 
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:279) 
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:136) 
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:86) 
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:136) 
at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:74) 
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1347) 
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1279) 
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1229) 
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1219) 
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:419) 
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537) 
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848) 
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1534) 
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281) 
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) 
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655) 
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595) 
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98) 
at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91) 
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162) 
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:326) 
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:227) 
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:170) 
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:822) 
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:719) 
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1013) 
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225) 
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137) 
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104) 
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90) 
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79) 
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54) 
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59) 
at com.sun.grizzly.ContextTask.run(ContextTask.java:71) 
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532) 
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513) 
at java.lang.Thread.run(Thread.java:662) 

回答

5

理想的REST风格的一流的设计应该是stateless,在本article解释说:

无状态服务不仅执行得更好,而且转换大部分维护状态的责任客户端应用程序

如果您的Stateless注释添加到您的Ressource类,你可以注入你的Facade会话bean,容器会照顾你的会话bean的生命周期。

这将使您的代码顺利运行,没有例外。

不要忘了让你的getUser方法返回一个值!

public String getUser(@PathParam("userid") String userid) { 

     facade.test(); 

     return "{" + userid + "}"; 
    }