[CAMEL-12926] null pointer exceptions accessing swagger url in blueprint projects

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.23.0
• Fix Version/s: 2.23.0
• Component/s: camel-swagger
• Estimated Complexity: Unknown
• Assignee: Andrea Tarocchi
• Reporter: Andrea Tarocchi
• Created: 09/Nov/18 15:26
• Updated: 14/Nov/18 16:56
• Resolved: 14/Nov/18 15:36

Description

When a blueprint like:

<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:ext="http://aries.apache.org/blueprint/xmlns/blueprint-ext/v1.5.0"
           xsi:schemaLocation="
             http://www.osgi.org/xmlns/blueprint/v1.0.0 https://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd
             http://camel.apache.org/schema/blueprint http://camel.apache.org/schema/blueprint/camel-blueprint.xsd">
  
  <reference id="httpService" interface="org.osgi.service.http.HttpService"/>

  <bean class="org.apache.camel.component.servlet.osgi.OsgiServletRegisterer"
        init-method="register"
        destroy-method="unregister">
    <property name="alias" value="/camel-rest-sql"/>
    <property name="httpService" ref="httpService"/>
    <property name="servlet" ref="camelServlet"/>
  </bean>

  <bean id="camelServlet" class="org.apache.camel.component.servlet.CamelHttpTransportServlet"/>

  <camelContext xmlns="http://camel.apache.org/schema/blueprint">

    <restConfiguration
        component="servlet"
        bindingMode="json"
        contextPath="/camel-rest-sql" port="{{env:HTTP_PORT:8181}}"
        apiContextPath="/api-doc">
    </restConfiguration>

    <rest path="/books" consumes="application/json" produces="application/json">
      <get uri="/" outType="java.util.String">
        <to uri="log:blueprint-swagger"/>
      </get>
    </rest>

  </camelContext>
</blueprint>

and then one try to access http://localhost:8181/camel-rest-sql/api-doc there is a null pointer exception:

2018-11-03 08:31:37,062 | INFO  | ead #2 - timer://foo | generateOrder-route              | 120 - org.apache.camel.camel-core - 2.21.0.fuse-720040 | Inserted new order 1

2018-11-03 08:31:37,547 | INFO  | rocessed%20=%20false | processOrder-route               | 120 - org.apache.camel.camel-core - 2.21.0.fuse-720040 | Processed order id 1 item ActiveMQ of 10 copies of ActiveMQ in Action

2018-11-03 08:31:45,741 | WARN  | qtp1210359820-76     | o.a.c.s.RestSwaggerProcessor     | 125 - org.apache.camel.camel-swagger-java - 2.21.0.fuse-720040 | Error rendering Swagger API due null

java.lang.NullPointerException: null

	at org.apache.camel.swagger.RestSwaggerSupport.renderResourceListing(RestSwaggerSupport.java:211) ~[?:?]

	at org.apache.camel.swagger.RestSwaggerProcessor.process(RestSwaggerProcessor.java:119) ~[?:?]

	at org.apache.camel.component.rest.RestApiProducer.process(RestApiProducer.java:36) ~[?:?]

	at org.apache.camel.util.AsyncProcessorConverterHelper$ProcessorToAsyncProcessorBridge.process(AsyncProcessorConverterHelper.java:61) ~[?:?]

	at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:148) ~[?:?]

	at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:548) ~[?:?]

	at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:201) ~[?:?]

	at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:201) ~[?:?]

	at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:97) ~[?:?]

	at org.apache.camel.http.common.CamelServlet.doService(CamelServlet.java:214) ~[?:?]

	at org.apache.camel.http.common.CamelServlet.service(CamelServlet.java:80) ~[?:?]

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) ~[36:javax.servlet-api:3.1.0]

	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:865) ~[?:?]

	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:535) ~[?:?]

	at org.ops4j.pax.web.service.jetty.internal.HttpServiceServletHandler.doHandle(HttpServiceServletHandler.java:71) ~[?:?]

	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146) ~[?:?]

	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548) ~[?:?]

	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) ~[?:?]

	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257) ~[?:?]

	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595) ~[?:?]

	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255) ~[?:?]

	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1317) ~[?:?]

	at org.ops4j.pax.web.service.jetty.internal.HttpServiceContext.doHandle(HttpServiceContext.java:293) ~[?:?]

	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203) ~[?:?]

	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473) ~[?:?]

	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564) ~[?:?]

	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201) ~[?:?]

	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1219) ~[?:?]

	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144) ~[?:?]

	at org.ops4j.pax.web.service.jetty.internal.JettyServerHandlerCollection.handle(JettyServerHandlerCollection.java:80) ~[?:?]

	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132) ~[?:?]

	at org.eclipse.jetty.server.Server.handle(Server.java:531) ~[?:?]

	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:352) ~[?:?]

	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260) ~[?:?]

	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:281) ~[?:?]

	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:102) ~[?:?]

	at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118) ~[?:?]

	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333) ~[94:org.eclipse.jetty.util:9.4.11.v20180605]

	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310) ~[94:org.eclipse.jetty.util:9.4.11.v20180605]

	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168) ~[94:org.eclipse.jetty.util:9.4.11.v20180605]

	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.produce(EatWhatYouKill.java:132) ~[94:org.eclipse.jetty.util:9.4.11.v20180605]

	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:762) [94:org.eclipse.jetty.util:9.4.11.v20180605]

	at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:680) [94:org.eclipse.jetty.util:9.4.11.v20180605]

	at java.lang.Thread.run(Thread.java:748) [?:?]

this is happening because restConfiguration is build with apiProperties as null because there is no tag <apiProperty key="" value=""/> inside <restConfiguration> tag; thus the null pointer here: https://github.com/apache/camel/blob/master/components/camel-swagger-java/src/main/java/org/apache/camel/swagger/RestSwaggerSupport.java#L213-L215

What do you think is the best approach to fix this:

• check for null in RestSwaggerSupport.java
• or investigate why blueprint use initialize apiProperties as null (which I think might be a legitimate behaviour)

Issue Links

• is caused by: CAMEL-12846 Allow customization of REST API documentation Content-Type
• links to: GitHub Pull Request #2617