使用openstack4j在Bluemix中部署对象存储时出错

Question

我目前正在使用openstack4j库连接到Bluemix中的对象存储。当我尝试将java代码作为java应用程序在本地运行时，连接似乎可以工作，但当我在Bluemix中部署与Java web应用程序相同的代码时，我得到以下错误。当我尝试执行authenticate方法时，会出现失败的代码：

OSClient os = OSFactory.builderV3()
                 .endpoint(auth_url)
                 .credentials(username, password)
                 .scopeToProject(projectIdent, domainIdent)
                 .authenticate();

 Exception thrown by application class 'org.openstack4j.connectors.jersey2.HttpExecutorServiceImpl.invoke:58'
org.openstack4j.api.exceptions.ConnectionException: org.apache.cxf.interceptor.Fault: No message body writer has been found for class org.openstack4j.openstack.identity.domain.v3.KeystoneAuth, ContentType: application/json
at org.openstack4j.connectors.jersey2.HttpExecutorServiceImpl.invoke(HttpExecutorServiceImpl.java:58)
at org.openstack4j.connectors.jersey2.HttpExecutorServiceImpl.execute(HttpExecutorServiceImpl.java:33)
at org.openstack4j.core.transport.internal.HttpExecutor.execute(HttpExecutor.java:51)
at org.openstack4j.openstack.internal.OSAuthenticator.authenticateV3(OSAuthenticator.java:156)
at org.openstack4j.openstack.internal.OSAuthenticator.invoke(OSAuthenticator.java:78)
at org.openstack4j.openstack.client.OSClientBuilder$ClientV3.authenticate(OSClientBuilder.java:163)
at org.openstack4j.openstack.client.OSClientBuilder$ClientV3.authenticate(OSClientBuilder.java:127)
at com.ibm.sample.ObjectStorageService.(ObjectStorageService.java:36)
at wasdev.sample.servlet.SimpleServlet.doGet(SimpleServlet.java:30)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1290)
at [internal classes]
Caused by: javax.ws.rs.ProcessingException: org.apache.cxf.interceptor.Fault: No message body writer has been found for class org.openstack4j.openstack.identity.domain.v3.KeystoneAuth, ContentType: application/json
at org.apache.cxf.jaxrs.client.WebClient.doResponse(WebClient.java:1206)
at [internal classes]
at org.openstack4j.connectors.jersey2.HttpCommand.execute(HttpCommand.java:79)
at org.openstack4j.connectors.jersey2.HttpExecutorServiceImpl.invokeRequest(HttpExecutorServiceImpl.java:65)
at org.openstack4j.connectors.jersey2.HttpExecutorServiceImpl.invoke(HttpExecutorServiceImpl.java:56)
... 12 more
Caused by: org.apache.cxf.interceptor.Fault: No message body writer has been found for class org.openstack4j.openstack.identity.domain.v3.KeystoneAuth, ContentType: application/json
at org.apache.cxf.jaxrs.client.WebClient$BodyWriter.doWriteBody(WebClient.java:1286)
... 16 more
Caused by: javax.ws.rs.ProcessingException: No message body writer has been found for class org.openstack4j.openstack.identity.domain.v3.KeystoneAuth, ContentType: application/json
at org.apache.cxf.jaxrs.client.AbstractClient.reportMessageHandlerProblem(AbstractClient.java:758)
... 16 more
Caused by: org.codehaus.jackson.map.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: org.openstack4j.openstack.identity.domain.v3.KeystoneAuth["id"])
at org.codehaus.jackson.map.JsonMappingException.wrapWithPath(JsonMappingException.java:215)
... 16 more
Caused by: java.lang.NullPointerException:
at org.openstack4j.openstack.identity.domain.v3.KeystoneAuth.getId(KeystoneAuth.java:90)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.codehaus.jackson.map.ser.BeanPropertyWriter.get(BeanPropertyWriter.java:285)

Answer 1

堆栈跟踪是由WebSphere自由配置文件中包含的默认jar文件集与使用OpenStack4J拉入的jar文件之间的jar文件冲突引起的。罪魁祸首很可能是jaxrs-2.0，它拉出了Jersey依赖项。

Liberty配置文件的Bluemix文档列出了自动包含在此处的jar文件：https://www.ng.bluemix.net/docs/#starters/liberty/index.html#liberty

(在该页面上搜索此文本:整个默认的自由server.xml配置文件如下所示)

要解决此问题，请将您的应用程序部署到Bluemix，因为上面提到的normal..and将失败。

然后发出cloud foundry命令(cf)，指示WebSphere Liberty不要加载其整个默认jars列表。

下面是一个cf命令示例，它将WebSphere Liberty加载的默认jar列表减少到只有2个jar文件，并去掉了jaxrs：

cf set-env <your app name here> JBP_CONFIG_LIBERTY "app_archive: {features: [jsp-2.3, websocket-1.1]}"

发出上述命令后，您必须重新准备您的Liberty应用程序，以使更改生效：

cf restage <your app name here>

此时，您的openstack4j调用应该可以工作了。您必须根据您的代码确定此列表应包含的内容：

{features: [jsp-2.3, websocket-1.1]}

还有其他选项可以避免类路径冲突。您可以下载OpenStack4J源代码，修改pom文件以对依赖项进行着色，并在Bluemix中使用此自定义版本的openstack4j。

WebSphere自由文档建议使用“反向类加载”，但这听起来不是最好的方法。

Answer 2

我相信这是由于从您的开发机器到Bluemix的java环境的不同。它不是特定于openstack或keystone的。

我建议回顾一下下面的堆栈溢出问题--它提出了一些配置更改：

CXF: No message body writer found for class - automatically mapping non-simple resources

如果您无法控制提供者，我会打开Bluemix支持票证，询问哪些/版本是环境的一部分。