问题
Getting null pointer exception on trying to integrate spring with cometd oort cluster:
<servlet>
<servlet-name>cometd</servlet-name>
<servlet-class>org.cometd.server.CometdServlet</servlet-class>
<init-param>
<param-name>transports</param-name>
<param-value>org.cometd.websocket.server.WebSocketTransport</param-value>
</init-param>
<async-supported>true</async-supported>
</servlet>
<servlet-mapping>
<servlet-name>cometd</servlet-name>
<url-pattern>/cometd/*</url-pattern>
</servlet-mapping>
Found this information on internet :If you use Spring to configure CometD objects, then you must not use configuration servlets such as OortMulticastConfigServlet. All your configuration belongs to Spring and you do everything in the initializer.
<!--
<servlet>
<servlet-name>oort</servlet-name>
<servlet-class>org.cometd.oort.OortStaticConfigServlet</servlet-class>
<init-param>
<param-name>oort.url</param-name>
<param-value>http://10.30.3.106:9080/project/cometd</param-value>
</init-param>
<init-param>
<param-name>oort.cloud</param-name>
<param-value>http://10.30.1.112:8080/project/cometd</param-value>
</init-param>
</servlet> -->
Does seti need to be configured in web.xml when using Spring ?
<servlet>
<servlet-name>seti</servlet-name>
<servlet-class>org.cometd.oort.SetiServlet</servlet-class>
</servlet>
Cometd Integration with Spring :
package com.efacec.oms.powr.cometd;
import javax.annotation.PostConstruct;
import javax.inject.Inject;
import javax.inject.Singleton;
import javax.servlet.ServletContext;
import org.apache.log4j.Logger;
import org.cometd.annotation.ServerAnnotationProcessor;
import org.cometd.bayeux.server.BayeuxServer;
import org.cometd.oort.Oort;
import org.cometd.oort.Seti;
import org.cometd.server.BayeuxServerImpl;
import org.cometd.server.ext.TimesyncExtension;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.config.DestructionAwareBeanPostProcessor;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
import org.springframework.web.context.ServletContextAware;
@Component
@Singleton
public class Configurer implements DestructionAwareBeanPostProcessor, ServletContextAware
{
private BayeuxServer bayeuxServer;
private ServerAnnotationProcessor processor;
private Oort oort;
private Seti seti;
private Logger logger = Logger.getLogger(this.getClass());
@Autowired
BayeuxAuthenticator bayeuxAuthenticator;
@Inject
private void setBayeuxServer(BayeuxServer bayeuxServer)
{
this.bayeuxServer = bayeuxServer;
this.bayeuxServer.addExtension(new TimesyncExtension());
// BayeuxAuthenticator authenticator = new BayeuxAuthenticator();
this.bayeuxServer.setSecurityPolicy(bayeuxAuthenticator);
}
@PostConstruct
public void init()
{
this.processor = new ServerAnnotationProcessor(bayeuxServer);
}
public Object postProcessBeforeInitialization(Object bean, String name) throws BeansException
{
processor.processDependencies(bean);
processor.processConfigurations(bean);
processor.processCallbacks(bean);
return bean;
}
public Object postProcessAfterInitialization(Object bean, String name) throws BeansException
{
return bean;
}
public void postProcessBeforeDestruction(Object bean, String name) throws BeansException
{
processor.deprocessCallbacks(bean);
}
@Bean(initMethod = "start", destroyMethod = "stop")
public BayeuxServer bayeuxServer()
{
BayeuxServerImpl bean = new BayeuxServerImpl();
bean.setOption(BayeuxServerImpl.LOG_LEVEL, "3");
// bean.setOption(BayeuxServerImpl., "3");
return bean;
}
@Bean(name="oort", initMethod = "start", destroyMethod="stop")
public Oort oort()
{
oort = new Oort(this.bayeuxServer,"oortion");
//Using bayeuxServer(), throw null pointer exception
return oort;
}
Is it really required to set Attribute Seti and oort on servlet Context?
@Bean(name="seti", initMethod = "start", destroyMethod="stop")
public Seti seti(){
Seti seti = new Seti(oort);
return seti;
}
public void setServletContext(ServletContext servletContext)
{
servletContext.setAttribute(BayeuxServer.ATTRIBUTE, bayeuxServer);
// servletContext.setAttribute(Seti.SETI_ATTRIBUTE, seti);
// servletContext.setAttribute(Oort.OORT_ATTRIBUTE, oort);
}
}
Cannot associate userId with session. seti.associate(loginUserId, serverSession); Cannot Inject Seti and OOrt in Security policy.
package com.efacec.oms.powr.cometd;
import java.util.HashMap;
import java.util.Map;
import javax.inject.Inject;
import javax.inject.Singleton;
import javax.servlet.ServletContext;
import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import org.cometd.bayeux.server.BayeuxServer;
import org.cometd.bayeux.server.ServerMessage;
import org.cometd.bayeux.server.ServerSession;
import org.cometd.oort.Oort;
import org.cometd.oort.OortComet;
import org.cometd.oort.Seti;
import org.cometd.server.DefaultSecurityPolicy;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
import org.springframework.web.context.ServletContextAware;
@Component
@Singleton
public class BayeuxAuthenticator extends DefaultSecurityPolicy implements ServerSession.RemoveListener // (1)
{
private Seti seti;
private Oort oort;
private Logger logger = Logger.getLogger(this.getClass());
@Autowired
public void setSeti(Seti seti) {
this.seti = seti;
}
@Autowired
public void setOort(Oort oort) {
this.oort = oort;
}
@Override
public boolean canHandshake(BayeuxServer server, ServerSession serverSession, ServerMessage message) //(2)
{
if (serverSession.isLocalSession()) //(3)
return true;
// Remote Oort comets are allowed to handshake
/* if (oort.isOortHandshake(message))
return true;
*/
Map<String, Object> ext = message.getExt();
if (ext == null)
return false;
@SuppressWarnings("unchecked")
Map<String, Object> authentication = (Map<String, Object>)ext.get("authentication");
if (authentication == null)
return false;
Object user=authentication.get("user");
String loginUserId=user.toString();
boolean user_is_number=StringUtils.isNumeric(loginUserId) ? true:false;
seti.associate(loginUserId, serverSession);
serverSession.addListener(this); // (6)
return true;
}
else
{
logger.debug("Authentication Failure !! ::"+serverSession.getId());
serverSession.addListener(this); // (6)
return false;
}
}
public void removed(ServerSession remote, boolean expired) // (7)
{
}
}
Error Message :
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'configurer': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.efacec.oms.powr.cometd.BayeuxAuthenticator com.efacec.oms.powr.cometd.Configurer.bayeuxAuthenticator; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'bayeuxAuthenticator': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void com.efacec.oms.powr.cometd.BayeuxAuthenticator.setSeti(org.cometd.oort.Seti); nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'seti' defined in class path resource [com/efacec/oms/powr/cometd/Configurer.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.cometd.oort.Seti com.efacec.oms.powr.cometd.Configurer.seti()] threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
at org.springframework.context.support.PostProcessorRegistrationDelegate.registerBeanPostProcessors(PostProcessorRegistrationDelegate.java:232)
at org.springframework.context.support.AbstractApplicationContext.registerBeanPostProcessors(AbstractApplicationContext.java:618)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:467)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4992)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5490)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.efacec.oms.powr.cometd.BayeuxAuthenticator com.efacec.oms.powr.cometd.Configurer.bayeuxAuthenticator; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'bayeuxAuthenticator': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void com.efacec.oms.powr.cometd.BayeuxAuthenticator.setSeti(org.cometd.oort.Seti); nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'seti' defined in class path resource [com/efacec/oms/powr/cometd/Configurer.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.cometd.oort.Seti com.efacec.oms.powr.cometd.Configurer.seti()] threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:508)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
... 23 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'bayeuxAuthenticator': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void com.efacec.oms.powr.cometd.BayeuxAuthenticator.setSeti(org.cometd.oort.Seti); nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'seti' defined in class path resource [com/efacec/oms/powr/cometd/Configurer.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.cometd.oort.Seti com.efacec.oms.powr.cometd.Configurer.seti()] threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1017)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:960)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:858)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480)
... 25 more
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void com.efacec.oms.powr.cometd.BayeuxAuthenticator.setSeti(org.cometd.oort.Seti); nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'seti' defined in class path resource [com/efacec/oms/powr/cometd/Configurer.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.cometd.oort.Seti com.efacec.oms.powr.cometd.Configurer.seti()] threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
... 36 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'seti' defined in class path resource [com/efacec/oms/powr/cometd/Configurer.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.cometd.oort.Seti com.efacec.oms.powr.cometd.Configurer.seti()] threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:597)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1094)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:989)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1017)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:960)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:858)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:553)
... 38 more
Caused by: org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.cometd.oort.Seti com.efacec.oms.powr.cometd.Configurer.seti()] threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:188)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:586)
... 50 more
**Caused by: java.lang.NullPointerException
at org.cometd.oort.Seti.<init>(Seti.java:82)
at com.efacec.oms.powr.cometd.Configurer.seti(Configurer.java:100)
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** org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:166)
... 51 more
回答1:
I have added an example on how to configure Oort and Seti using Spring annotations.
As for your questions:
The
NullPointerExceptionis due to the fact that methods on yourConfigurerclass are called in an order that you don't expect. By the way,Configurershould be annotated with Spring's@Configurationrather than@Component(COMETD-547).SetiServletis the configuration Servlet forSeti, so if you configure CometD using Spring, you should configureSetiin Spring, not inweb.xml.Setting
OortandSetiasServletContextattribute is strongly recommended. It's a simple one liner in the Spring configuration, and allows you for full compatibility with code that uses those attributes.
Follow the example I linked above, and everything should be good.
来源：https://stackoverflow.com/questions/25790256/cometd-oort-cluster-spring-integration