无法在启用 Jaxrs-2.0 功能的情况下调用 REST 1.1 服务

Question

我在 Java 1.8 上使用 Liberty 配置文件 16，并启用了以下功能：

<featureManager>
        <feature>jsp-2.3</feature>
        <feature>wasJmsServer-1.0</feature>
        <feature>wasJmsClient-2.0</feature>
        <feature>jndi-1.0</feature>
        <feature>ejbLite-3.2</feature>
        <feature>servlet-3.1</feature>
        <feature>jdbc-4.0</feature>
        <feature>localConnector-1.0</feature>
        <feature>jaxrs-2.0</feature>
    </featureManager>

我在此使用 Apache Wink 作为我的休息提供者并将其添加为第三方库。

<library id="winkLib" >
        <fileset dir="E:\Software\Jars\wink1.4\apache-wink-1.4\lib" includes="*.jar" scanInterval="5s"></fileset>
    </library>

    <enterpriseApplication location="E:\wlp9\usr\servers\servername\apps\myear.ear">
        <classloader commonLibraryRef="winkLib" />
    </enterpriseApplication>

REST 服务已成功注册，但当我尝试访问该服务时出现以下错误：

10:43:04,241 INFO  [User=] [RequestInterceptor] Initializing Request Hanlder
10:43:04,256 INFO  [User=] [ResponseInterceptor] Initializing response interceptor
[INFO    ] The following error occurred during the invocation of the handlers chain: NullPointerException with message 'null' while processing POST request sent to http://localhost:8081/myapp/rest/login
10:43:04,287 WARN  [User=] [RestExceptionHandler] Exception Hanlder Invoked
10:43:04,287 ERROR [User=] [RestExceptionHandler] 
****************************************************************************************************
Message Info:java.lang.NullPointerException

****************************************************************************************************
[ERROR   ] The system cannot determine the class of type null.
[ERROR   ] An unhandled exception occurred which will be propagated to the container.
java.lang.NullPointerException
[ERROR   ] SRVE0777E: Exception thrown by application class 'java.lang.Class.isAssignableFrom:-2'
java.lang.NullPointerException
    at java.lang.Class.isAssignableFrom(Native Method)
    at org.apache.wink.common.internal.registry.ProvidersRegistry$MediaTypeMap$OFHolder.compareTo(ProvidersRegistry.java:1008)
    at org.apache.wink.common.internal.registry.ProvidersRegistry$MediaTypeMap$OFHolder.compareTo(ProvidersRegistry.java:906)
    at java.util.Collections$ReverseComparator.compare(Collections.java:5117)
    at java.util.Collections$ReverseComparator.compare(Collections.java:5108)
    at java.util.TreeMap.put(TreeMap.java:552)
    at java.util.TreeSet.add(TreeSet.java:255)
    at org.apache.wink.common.internal.registry.ProvidersRegistry$MediaTypeMap.internalGetProvidersByMediaType(ProvidersRegistry.java:752)
    at org.apache.wink.common.internal.registry.ProvidersRegistry$MediaTypeMap.getProvidersByMediaType(ProvidersRegistry.java:711)
    at org.apache.wink.common.internal.registry.ProvidersRegistry.getMessageBodyWriter(ProvidersRegistry.java:445)
    at org.apache.wink.common.internal.contexts.ProvidersImpl.getMessageBodyWriter(ProvidersImpl.java:72)
    at org.apache.wink.server.internal.handlers.FlushResultHandler.handleResponse(FlushResultHandler.java:144)
    at org.apache.wink.server.handlers.AbstractHandler.handleResponse(AbstractHandler.java:38)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.handlers.AbstractHandler.handleResponse(AbstractHandler.java:39)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.handlers.AbstractHandler.handleResponse(AbstractHandler.java:39)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.handlers.AbstractHandler.handleResponse(AbstractHandler.java:39)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.internal.log.Responses.handleResponse(Responses.java:90)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.handlers.AbstractHandlersChain.run(AbstractHandlersChain.java:60)
    at org.apache.wink.server.internal.RequestProcessor.handleRequestWithoutFaultBarrier(RequestProcessor.java:232)
    at org.apache.wink.server.internal.RequestProcessor.handleRequest(RequestProcessor.java:154)
    at org.apache.wink.server.internal.servlet.RestServlet.service(RestServlet.java:124)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at [internal classes]

[INFO    ] FFDC1015I: An FFDC Incident has been created: "java.lang.NullPointerException com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters 1105" at ffdc_17.03.09_10.43.04.0.log
[ERROR   ] SRVE0315E: An exception occurred: java.lang.Throwable: java.lang.NullPointerException
    at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:4983)
    at [internal classes]
Caused by: java.lang.NullPointerException
    at java.lang.Class.isAssignableFrom(Native Method)
    at org.apache.wink.common.internal.registry.ProvidersRegistry$MediaTypeMap$OFHolder.compareTo(ProvidersRegistry.java:1008)
    at org.apache.wink.common.internal.registry.ProvidersRegistry$MediaTypeMap$OFHolder.compareTo(ProvidersRegistry.java:906)
    at java.util.Collections$ReverseComparator.compare(Collections.java:5117)
    at java.util.Collections$ReverseComparator.compare(Collections.java:5108)
    at java.util.TreeMap.put(TreeMap.java:552)
    at java.util.TreeSet.add(TreeSet.java:255)
    at org.apache.wink.common.internal.registry.ProvidersRegistry$MediaTypeMap.internalGetProvidersByMediaType(ProvidersRegistry.java:752)
    at org.apache.wink.common.internal.registry.ProvidersRegistry$MediaTypeMap.getProvidersByMediaType(ProvidersRegistry.java:711)
    at org.apache.wink.common.internal.registry.ProvidersRegistry.getMessageBodyWriter(ProvidersRegistry.java:445)
    at org.apache.wink.common.internal.contexts.ProvidersImpl.getMessageBodyWriter(ProvidersImpl.java:72)
    at org.apache.wink.server.internal.handlers.FlushResultHandler.handleResponse(FlushResultHandler.java:144)
    at org.apache.wink.server.handlers.AbstractHandler.handleResponse(AbstractHandler.java:38)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.handlers.AbstractHandler.handleResponse(AbstractHandler.java:39)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.handlers.AbstractHandler.handleResponse(AbstractHandler.java:39)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.handlers.AbstractHandler.handleResponse(AbstractHandler.java:39)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.internal.log.Responses.handleResponse(Responses.java:90)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:26)
    at org.apache.wink.server.handlers.ResponseHandlersChain.handle(ResponseHandlersChain.java:22)
    at org.apache.wink.server.handlers.AbstractHandlersChain.doChain(AbstractHandlersChain.java:75)
    at org.apache.wink.server.handlers.AbstractHandlersChain.run(AbstractHandlersChain.java:60)
    at org.apache.wink.server.internal.RequestProcessor.handleRequestWithoutFaultBarrier(RequestProcessor.java:232)
    at org.apache.wink.server.internal.RequestProcessor.handleRequest(RequestProcessor.java:154)
    at org.apache.wink.server.internal.servlet.RestServlet.service(RestServlet.java:124)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    ... 1 more

这是我的 web.xml 样子：

<servlet>
        <servlet-name>JAX-RS Servlet</servlet-name>
        <servlet-class>org.apache.wink.server.internal.servlet.RestServlet</servlet-class>
        <init-param>
            <param-name>javax.ws.rs.Application</param-name>
            <param-value>package.name.RestfulResourceLoader</param-value>
        </init-param>
        <init-param>
        <param-name>propertiesLocation</param-name>
        <param-value>handler.properties</param-value>
     </init-param>
     <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>JAX-RS Servlet</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>

Answer 1

这看起来像是 Wink 中的错误。虽然您的共享库表明您使用的是 Wink 1.4，但堆栈跟踪中的源代码行号更接近于 Wink 1.2.1。也许这个问题在更新版本的 Wink 中得到了解决。

您的配置肯定容易出错，因为您使用的是 jaxrs-2.0 功能（除其他事项外，它告诉 Liberty 服务器使 JAX-RS 2.0 API 包可用于应用程序）但尝试使用不同的 JAX-RS 提供程序。这里还有一个版本冲突——Wink 实现了 JAX-RS 1.1。如果我对这个配置的理解正确，那么您正在使用 Wink 作为 JAX-RS 提供程序，但使用的是 Liberty 附带的 JAX-RS 2.0 APIs。即使这不是您所看到的问题的原因，以后也可能会导致问题。

如果您想使用 Wink，我建议您将其从您的应用程序中删除，然后使用 jaxrs-1.1 功能部件（而不是 jaxrs-2.0 功能部件）。 Liberty 的 jaxrs-1.1。实现是 Wink，它使许多特定于 Wink 的 API 可用。

如果您只需要一个 JAX-RS 提供程序（与 Wink 无关），那么我建议从您的应用程序中删除 Wink 库，并使用内置于 jaxrs-2.0 功能的 CXF 实现。这需要制作一些 changes to the web.xml.

安迪，希望这对你有所帮助

无法在启用 Jaxrs-2.0 功能的情况下调用 REST 1.1 服务

unable to call REST 1.1 Service with Jaxrs-2.0 feature enabled

websphere

apache-wink

websphere-8

websphere-liberty