如何从轻量级客户端对WebSphere Liberty进行远程EJB调用

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英文:

How to make remote EJB call from thin client to WebSphere Liberty

问题

以下是翻译好的内容：

我正试图从一个非常轻量级的客户端向WebSphere Liberty 20.0.0.10（JDK 8）进行远程 EJB 3 调用。该客户端并未在 EJB 容器中运行。我在 Google 上找到了这个页面，并尝试遵循其中的说明：
https://www.ibm.com/support/knowledgecenter/SSD28V_liberty/com.ibm.websphere.wlp.core.doc/ae/twlp_ejb_remote.html

根据服务器日志，该 EJB 绑定到了这个地址：

CNTR0167I: 服务器正在绑定 codeserver 应用模块中 DW_CS_LoggingRemoteServicesBean 企业 bean 的 fi.datawell.cs.ejb.logging.boundary.DW_CS_LoggingServices 接口。绑定位置为：java:global/codeserver/DW_CS_LoggingRemoteServicesBean!fi.datawell.cs.ejb.logging.boundary.DW_CS_LoggingServices

（codeserver 是应用的名称，且只有一个包含 EJB 的 war 模块）

我可以在本地调用它而没有问题。我尝试用以下字符串来远程查找它：

corbaname::localhost:12809#ejb/global/codeserver/DW_CS_LoggingRemoteServicesBean!fi\.datawell\.cs\.ejb\.logging\.boundary\.DW_CS_LoggingServices

（IIOP 服务位于端口 12809）

然而，不知何故，我在日志中得到了这个错误，尽管它没有在应用程序中引发异常：

WARNING: "IOP00410201: (COMM_FAILURE) 连接失败：socketType: IIOP_CLEAR_TEXT；hostname: localhost；port: 0"
org.omg.CORBA.COMM_FAILURE:   vmcid: SUN  minor code: 201  completed: No
        at com.sun.corba.se.impl.logging.ORBUtilSystemException.connectFailure(ORBUtilSystemException.java:2200)
        at ...

该地址似乎是正确的，因为如果我更改端口，我会得到“连接被拒绝”，如果我更改 bean 名称，我会得到 NameNotFoundException。

我得到了一个 com.sun.corba.se.impl.corba.CORBAObjectImpl 的实例作为响应，但当我使用 PortableRemoteObject.narrow() 方法时，我得到了一个空值而没有任何异常。现在我想知道我做错了什么。即使这是 EJB 3 应用程序，我是否需要某种 EJB 存根？

补充说明：实际上，我们正在从传统的 WebSphere 迁移到 WebSphere Liberty，我认为我们可以摆脱运行 createEJBStubs 的步骤，因为它很慢（使用 maven 插件）并且需要 WAS 传统安装（在 Mac 上不可用）。现在我尝试了一下 createEJBStubs，进展有了一些。首先，我必须将 com.ibm.websphere.javaee.ejb.3.2_1.0.45.jar 添加到类路径中。在这之后，事情稍微有所进展。我可以获取到 EJB，但第一次尝试使用它时会失败，出现了一个熟悉的异常：

javax.ejb.EJBException: 嵌套异常为：java.rmi.MarshalException：CORBA COMM_FAILURE 1398079689 No；嵌套异常为：
	org.omg.CORBA.COMM_FAILURE:   vmcid: SUN  minor code: 201  completed: No
    at ...

现在我不知道接下来该尝试什么。每当检索到 EJB 时，仍然会在日志中出现相同的异常，但在这种情况下，它似乎被静默地消耗掉了。我不知道为什么异常中会有端口 0...

英文:

I'm trying to make a remote EJB 3 call from a thin client to WebSphere Liberty 20.0.0.10 (JDK 8). The client is not running in an EJB container. I googled this page and tried to follow the instructions:
https://www.ibm.com/support/knowledgecenter/SSD28V_liberty/com.ibm.websphere.wlp.core.doc/ae/twlp_ejb_remote.html

According to the server log, the EJB is bound to this address:

CNTR0167I: The server is binding the fi.datawell.cs.ejb.logging.boundary.DW_CS_LoggingServices interface of the DW_CS_LoggingRemoteServicesBean enterprise bean in the codeserver.war module of the codeserver application.  The binding location is: java:global/codeserver/DW_CS_LoggingRemoteServicesBean!fi.datawell.cs.ejb.logging.boundary.DW_CS_LoggingServices

(codeserver is the name of the application, and there's only a single war module which contains the EJBs)

I can call it locally without problems. I try to look it up remotely with this string:

corbaname::localhost:12809#ejb/global/codeserver/DW_CS_LoggingRemoteServicesBean!fi\.datawell\.cs\.ejb\.logging\.boundary\.DW_CS_LoggingServices

(The IIOP service is in port 12809)

Somehow I get this error in the log, although it doesn't cause an exception in the application.

WARNING: "IOP00410201: (COMM_FAILURE) Connection failure: socketType: IIOP_CLEAR_TEXT; hostname: localhost; port: 0"
org.omg.CORBA.COMM_FAILURE:   vmcid: SUN  minor code: 201  completed: No
        at com.sun.corba.se.impl.logging.ORBUtilSystemException.connectFailure(ORBUtilSystemException.java:2200)
        at com.sun.corba.se.impl.logging.ORBUtilSystemException.connectFailure(ORBUtilSystemException.java:2221)
        at com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.<init>(SocketOrChannelConnectionImpl.java:223)
        at com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.<init>(SocketOrChannelConnectionImpl.java:236)
        at com.sun.corba.se.impl.transport.SocketOrChannelContactInfoImpl.createConnection(SocketOrChannelContactInfoImpl.java:119)
        at com.sun.corba.se.impl.protocol.CorbaClientRequestDispatcherImpl.beginRequest(CorbaClientRequestDispatcherImpl.java:187)
        at com.sun.corba.se.impl.protocol.CorbaClientDelegateImpl.request(CorbaClientDelegateImpl.java:137)
        at com.sun.corba.se.impl.protocol.CorbaClientDelegateImpl.is_a(CorbaClientDelegateImpl.java:229)
        at org.omg.CORBA.portable.ObjectImpl._is_a(ObjectImpl.java:130)
        at org.omg.CosNaming.NamingContextHelper.narrow(NamingContextHelper.java:69)
        at com.sun.jndi.cosnaming.CNCtx.callResolve(CNCtx.java:504)
        at com.sun.jndi.cosnaming.CNCtx.lookup(CNCtx.java:555)
        at com.sun.jndi.toolkit.url.GenericURLContext.lookup(GenericURLContext.java:205)
        at javax.naming.InitialContext.lookup(InitialContext.java:417)
        at fi.datawell.cs.ejb.DW_CS_EjbFactory.lookupService(DW_CS_EjbFactory.java:91)
        at fi.datawell.cs.ejb.DW_CS_EjbFactory.lookupLoggingRemoteServicesEJB(DW_CS_EjbFactory.java:284)
        at fi.datawell.cs.application.clients.versionloader.DW_CS_VersionLoaderWorker.fetchClientServices(DW_CS_VersionLoaderWorker.java:983)
        at fi.datawell.cs.application.clients.versionloader.DW_CS_VersionLoader.initialize(DW_CS_VersionLoader.java:114)
        at fi.datawell.cs.application.clients.versionloader.DW_CS_VersionLoader.main(DW_CS_VersionLoader.java:252)
Caused by: java.net.BindException: Cannot assign requested address: connect
        at sun.nio.ch.Net.connect0(Native Method)
        at sun.nio.ch.Net.connect(Net.java:454)
        at sun.nio.ch.Net.connect(Net.java:446)
        at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:648)
        at java.nio.channels.SocketChannel.open(SocketChannel.java:189)
        at com.sun.corba.se.impl.transport.DefaultSocketFactoryImpl.createSocket(DefaultSocketFactoryImpl.java:95)
        at com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.<init>(SocketOrChannelConnectionImpl.java:207)
        ... 16 more

This address seems to be correct, because if I change the port, I get "connection refused" and if I change the bean name, I get NameNotFoundException.

I get an instance of com.sun.corba.se.impl.corba.CORBAObjectImpl as response, but when I use PortableRemoteObject.narrow() method, I get null without any exception. Now I wonder what I'm doing wrong. Do I need some kind of EJB stubs although this is EJB 3 application?

Addendum: Actually we are doing a migration from WebSphere traditional to WebSphere Liberty and I thought we could get rid of running createEJBStubs, because it is slow (using maven plugin) and requires WAS traditional installation (which isn't available for Mac). Now I tried with createEJBStubs and got a bit further. First I had to add com.ibm.websphere.javaee.ejb.3.2_1.0.45.jar to classpath. After that things get a bit further. I can fetch the EJB, but the first attempt to use it fails with a familiar exception:

javax.ejb.EJBException: nested exception is: java.rmi.MarshalException: CORBA COMM_FAILURE 1398079689 No; nested exception is: 
	org.omg.CORBA.COMM_FAILURE:   vmcid: SUN  minor code: 201  completed: No
	at fi.datawell.cs.ejb.logging.boundary._DW_CS_LoggingServices_Stub.log(_DW_CS_LoggingServices_Stub.java:1101)
	at fi.datawell.cs.application.clients.core.DW_CS_BaseWorker.writeCodeServerLog(DW_CS_BaseWorker.java:66)
	at fi.datawell.cs.application.clients.versionloader.DW_CS_VersionLoader.initialize(DW_CS_VersionLoader.java:120)
	at fi.datawell.cs.application.clients.versionloader.DW_CS_VersionLoader.main(DW_CS_VersionLoader.java:252)
Caused by: java.rmi.MarshalException: CORBA COMM_FAILURE 1398079689 No; nested exception is: 
	org.omg.CORBA.COMM_FAILURE:   vmcid: SUN  minor code: 201  completed: No
	at com.sun.corba.se.impl.javax.rmi.CORBA.Util.mapSystemException(Util.java:219)
	at javax.rmi.CORBA.Util.mapSystemException(Util.java:95)
	at fi.datawell.cs.ejb.logging.boundary._DW_CS_LoggingServices_Stub.log(_DW_CS_LoggingServices_Stub.java:1)
	... 3 more
Caused by: org.omg.CORBA.COMM_FAILURE:   vmcid: SUN  minor code: 201  completed: No
	at com.sun.corba.se.impl.logging.ORBUtilSystemException.connectFailure(ORBUtilSystemException.java:2200)
	at com.sun.corba.se.impl.logging.ORBUtilSystemException.connectFailure(ORBUtilSystemException.java:2221)
	at com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.<init>(SocketOrChannelConnectionImpl.java:223)
	at com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.<init>(SocketOrChannelConnectionImpl.java:236)
	at com.sun.corba.se.impl.transport.SocketOrChannelContactInfoImpl.createConnection(SocketOrChannelContactInfoImpl.java:119)
	at com.sun.corba.se.impl.protocol.CorbaClientRequestDispatcherImpl.beginRequest(CorbaClientRequestDispatcherImpl.java:187)
	at com.sun.corba.se.impl.protocol.CorbaClientDelegateImpl.request(CorbaClientDelegateImpl.java:137)
	at org.omg.CORBA.portable.ObjectImpl._request(ObjectImpl.java:449)
	at fi.datawell.cs.ejb.logging.boundary._DW_CS_LoggingServices_Stub.log(_DW_CS_LoggingServices_Stub.java)
	... 3 more
Caused by: java.net.BindException: Cannot assign requested address: connect
	at sun.nio.ch.Net.connect0(Native Method)
	at sun.nio.ch.Net.connect(Net.java:454)
	at sun.nio.ch.Net.connect(Net.java:446)
	at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:648)
	at java.nio.channels.SocketChannel.open(SocketChannel.java:189)
	at com.sun.corba.se.impl.transport.DefaultSocketFactoryImpl.createSocket(DefaultSocketFactoryImpl.java:95)
	at com.sun.corba.se.impl.transport.SocketOrChannelConnectionImpl.<init>(SocketOrChannelConnectionImpl.java:207)
	... 9 more

Now I don't know what to try next. The same exception still appears on log whenever the EJB is retrieved, but in that situation it seems to be silently consumed. I wonder why there is port 0 in the exception...

答案1

得分: 1

WebSphere Liberty没有提供EJB的轻量级客户端，但是您可以使用WebSphere传统的轻量级客户端来访问WebSphere Liberty服务器：

链接：https://www.ibm.com/support/knowledgecenter/SSAW57_8.5.5/com.ibm.websphere.nd.multiplatform.doc/ae/tcli_ejbthinclient.html

对于轻量级客户端，所有EJB远程接口都需要一个存根（Stub），无论是使用2.x还是3.x API。对于EJB 2.x，您可以使用带有-iiop选项的RMIC。对于EJB 3.x（本文中使用的版本），您需要使用WebSphere传统提供的createEJBStubs命令：

链接：https://www.ibm.com/support/knowledgecenter/en/SSEQTP_8.5.5/com.ibm.websphere.base.doc/ae/rejb_3stubscmd.html

createEJBStubs也可用于EJB 2.x远程接口。

请注意，在启用了ejbRemote-3.2特性的WebSphere服务器进程中，会为您生成存根（Stub），或者在应用程序客户端进程（即厚客户端）中生成。有关应用程序客户端的更多信息，请参见此处：

链接：https://www.ibm.com/support/knowledgecenter/SSEQTP_liberty/com.ibm.websphere.wlp.doc/ae/twlp_setup_prepareappclient.html

由于您正在收到CORBAObjectImpl，并且narrow方法无法正常工作，这至少部分说明问题是缺少存根（Stub）类所致。

英文:

WebSphere Liberty does not provide an EJB thin client, however, you may use the WebSphere traditional thin client to access a WebSphere Liberty server:

https://www.ibm.com/support/knowledgecenter/SSAW57_8.5.5/com.ibm.websphere.nd.multiplatform.doc/ae/tcli_ejbthinclient.html

For a thin client, all EJB remote interfaces require a Stub, whether using the 2.x or 3.x APIs. For EJB 2.x, you could use RMIC with the -iiop option. For EJB 3.x (that is being used here), you need to use the createEJBStubs command provided by WebSphere traditional :

https://www.ibm.com/support/knowledgecenter/en/SSEQTP_8.5.5/com.ibm.websphere.base.doc/ae/rejb_3stubscmd.html

createEJBStubs may also be used for EJB 2.x remote interfaces as well.

Note that a Stub is generated for you in a WebSphere server process that has the ejbRemote-3.2 feature enabled or in an application client process (i.e. thick client). More information about the application client is here:

https://www.ibm.com/support/knowledgecenter/SSEQTP_liberty/com.ibm.websphere.wlp.doc/ae/twlp_setup_prepareappclient.html

Since you are receiving a CORBAObjectImpl, and the narrow does not work, it would seem that at least part of the problem is the lack of Stub classes.

huangapple
  • 本文由 发表于 2020年10月13日 20:11:37
  • 转载请务必保留本文链接：https://go.coder-hub.com/64335018.html
  • jakarta-ee
  • java
  • websphere-liberty
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