wso2esb自定义中介类强制转换异常

Question

我编写了一个自定义类调解器，但是当我使用maven shade插件编译代码时，我无法在我的esb中部署它。我需要在包含所有依赖项的jar中编译我的mediator类。以下是错误的堆栈跟踪：

  [2015-11-09 10:01:28,088] ERROR - ClassMediatorFactory Error : com.solers.espds.util.messaging.mediators.FastTrackMediator
java.lang.ClassCastException: com.test.FastTrackMediator cannot be cast to org.apache.synapse.Mediator
    at org.apache.synapse.config.xml.ClassMediatorFactory.createSpecificMediator(ClassMediatorFactory.java:71)
    at org.apache.synapse.config.xml.AbstractMediatorFactory.createMediator(AbstractMediatorFactory.java:91)
    at org.apache.synapse.config.xml.MediatorFactoryFinder.getMediator(MediatorFactoryFinder.java:223)
    at org.apache.synapse.config.xml.AbstractListMediatorFactory.addChildren(AbstractListMediatorFactory.java:41)
    at org.apache.synapse.config.xml.SequenceMediatorFactory.createAnonymousSequence(SequenceMediatorFactory.java:70)
    at org.apache.synapse.config.xml.ProxyServiceFactory.createProxy(ProxyServiceFactory.java:178)
    at org.apache.synapse.config.xml.SynapseXMLConfigurationFactory.defineProxy(SynapseXMLConfigurationFactory.java:142)
    at org.apache.synapse.config.xml.MultiXMLConfigurationBuilder.createProxyServices(MultiXMLConfigurationBuilder.java:239)
    at org.apache.synapse.config.xml.MultiXMLConfigurationBuilder.getConfiguration(MultiXMLConfigurationBuilder.java:132)
    at org.apache.synapse.config.SynapseConfigurationBuilder.getConfiguration(SynapseConfigurationBuilder.java:100)
    at org.apache.synapse.Axis2SynapseController.createSynapseConfiguration(Axis2SynapseController.java:479)
    at org.wso2.carbon.mediation.initializer.CarbonSynapseController.createSynapseConfiguration(CarbonSynapseController.java:169)
    at org.apache.synapse.ServerManager.start(ServerManager.java:177)
    at org.wso2.carbon.mediation.initializer.ServiceBusInitializer.initESB(ServiceBusInitializer.java:424)
    at org.wso2.carbon.mediation.initializer.ServiceBusInitializer.activate(ServiceBusInitializer.java:182)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.eclipse.equinox.internal.ds.model.ServiceComponent.activate(ServiceComponent.java:260)
    at org.eclipse.equinox.internal.ds.model.ServiceComponentProp.activate(ServiceComponentProp.java:146)
    at org.eclipse.equinox.internal.ds.model.ServiceComponentProp.build(ServiceComponentProp.java:347)
    at org.eclipse.equinox.internal.ds.InstanceProcess.buildComponent(InstanceProcess.java:620)
    at org.eclipse.equinox.internal.ds.InstanceProcess.buildComponents(InstanceProcess.java:197)
    at org.eclipse.equinox.internal.ds.Resolver.getEligible(Resolver.java:343)
    at org.eclipse.equinox.internal.ds.SCRManager.serviceChanged(SCRManager.java:222)
    at org.eclipse.osgi.internal.serviceregistry.FilteredServiceListener.serviceChanged(FilteredServiceListener.java:107)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.dispatchEvent(BundleContextImpl.java:861)
    at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
    at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEventPrivileged(ServiceRegistry.java:819)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEvent(ServiceRegistry.java:771)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistrationImpl.register(ServiceRegistrationImpl.java:130)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.registerService(ServiceRegistry.java:214)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.registerService(BundleContextImpl.java:433)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.registerService(BundleContextImpl.java:451)
    at org.wso2.carbon.event.core.internal.builder.EventBrokerHandler.startEventBroker(EventBrokerHandler.java:58)
    at org.wso2.carbon.event.core.internal.builder.EventBrokerBuilderDS.activate(EventBrokerBuilderDS.java:72)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.eclipse.equinox.internal.ds.model.ServiceComponent.activate(ServiceComponent.java:260)
    at org.eclipse.equinox.internal.ds.model.ServiceComponentProp.activate(ServiceComponentProp.java:146)
    at org.eclipse.equinox.internal.ds.model.ServiceComponentProp.build(ServiceComponentProp.java:347)
    at org.eclipse.equinox.internal.ds.InstanceProcess.buildComponent(InstanceProcess.java:620)
    at org.eclipse.equinox.internal.ds.InstanceProcess.buildComponents(InstanceProcess.java:197)
    at org.eclipse.equinox.internal.ds.Resolver.getEligible(Resolver.java:343)
    at org.eclipse.equinox.internal.ds.SCRManager.serviceChanged(SCRManager.java:222)
    at org.eclipse.osgi.internal.serviceregistry.FilteredServiceListener.serviceChanged(FilteredServiceListener.java:107)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.dispatchEvent(BundleContextImpl.java:861)
    at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
    at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEventPrivileged(ServiceRegistry.java:819)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEvent(ServiceRegistry.java:771)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistrationImpl.register(ServiceRegistrationImpl.java:130)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.registerService(ServiceRegistry.java:214)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.registerService(BundleContextImpl.java:433)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.registerService(BundleContextImpl.java:451)
    at org.wso2.carbon.core.init.CarbonServerManager.initializeCarbon(CarbonServerManager.java:517)
    at org.wso2.carbon.core.init.CarbonServerManager.start(CarbonServerManager.java:219)
    at org.wso2.carbon.core.internal.CarbonCoreServiceComponent.activate(CarbonCoreServiceComponent.java:77)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.eclipse.equinox.internal.ds.model.ServiceComponent.activate(ServiceComponent.java:260)
    at org.eclipse.equinox.internal.ds.model.ServiceComponentProp.activate(ServiceComponentProp.java:146)
    at org.eclipse.equinox.internal.ds.model.ServiceComponentProp.build(ServiceComponentProp.java:347)
    at org.eclipse.equinox.internal.ds.InstanceProcess.buildComponent(InstanceProcess.java:620)
    at org.eclipse.equinox.internal.ds.InstanceProcess.buildComponents(InstanceProcess.java:197)
    at org.eclipse.equinox.internal.ds.Resolver.getEligible(Resolver.java:343)
    at org.eclipse.equinox.internal.ds.SCRManager.serviceChanged(SCRManager.java:222)
    at org.eclipse.osgi.internal.serviceregistry.FilteredServiceListener.serviceChanged(FilteredServiceListener.java:107)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.dispatchEvent(BundleContextImpl.java:861)
    at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
    at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEventPrivileged(ServiceRegistry.java:819)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.publishServiceEvent(ServiceRegistry.java:771)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistrationImpl.register(ServiceRegistrationImpl.java:130)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.registerService(ServiceRegistry.java:214)
    at org.eclipse.osgi.framework.internal.core.BundleContextImpl.registerService(BundleContextImpl.java:433)
    at org.eclipse.equinox.http.servlet.internal.Activator.registerHttpService(Activator.java:81)
    at org.eclipse.equinox.http.servlet.internal.Activator.addProxyServlet(Activator.java:60)
    at org.eclipse.equinox.http.servlet.internal.ProxyServlet.init(ProxyServlet.java:40)
    at org.wso2.carbon.tomcat.ext.servlet.DelegationServlet.init(DelegationServlet.java:38)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1267)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1186)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1081)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5027)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5314)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)

这是我的班级：

import org.apache.synapse.ManagedLifecycle;
import org.apache.synapse.MessageContext;
import org.apache.synapse.core.SynapseEnvironment;
import org.apache.synapse.mediators.AbstractMediator;

public class FastTrackMediator extends AbstractMediator implements ManagedLifecycle {
    public boolean mediate(MessageContext messageContext) {
        log.info("Hello, world!");

        return true;
    }

    public void init(SynapseEnvironment synapseEnvironment) {

    }

    public void destroy() {

    }
}

这是我的pom：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.test</groupId>
    <artifactId>fast-track-mediator</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>Fast Track Mediator</name>

    <repositories>
        <repository>
            <releases>
                <updatePolicy>daily</updatePolicy>
            </releases>
            <id>wso2-nexus</id>
            <url>http://maven.wso2.org/nexus/content/groups/wso2-public/</url>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>org.apache.synapse</groupId>
            <artifactId>synapse-core</artifactId>
            <scope>provided</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
             <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                         <configuration>
                            <relocations>
                               <relocation>
                                 <pattern>org.apache.synapse</pattern>
                                 <shadedPattern>org.apache.synapse.shaded</shadedPattern>
                               </relocation>
                             </relocations>
                             <artifactSet>
                               <excludes>

                                 <exclude>net.sf.saxon:*</exclude>
                               </excludes>

                             </artifactSet>
                           </configuration>

                    </execution>
                </executions>
                <configuration>
                    <finalName>uber-${artifactId}-${version}</finalName>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.apache.synapse</groupId>
                <artifactId>synapse-core</artifactId>
                <version>2.1.2-wso2v4</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

我想这个错误是OSGI加载某些类两次的结果，但我无法弄清楚如何解决这个问题。感谢

Answer 1

试图重现您的问题。但不能。它正确地为我构建并生成jar文件。我怀疑问题与您的环境有关。按照下面的步骤看看。

使用WSO2 Developer studio 3.8 （最好在新工作区尝试这个）

1. 创建新的Maven Multi模块项目。
2. 在多模块项目中创建新的ESB配置项目
3. 在项目一侧创建空序列（只是为了检测部署）
4. 在多模块项目中创建新的中介项目
5. 创建你的课程并像你一样实施。
6. 在同一工作区上创建新的复合应用程序项目，并为该复合项目选择两个项目

现在你已经完成了。

现在从命令提示符转到存在maven多模块项目pom文件的相同位置

mvn clean install

你可以毫无错误地看到它的构建。

maven multimodule pom（自动生成）

<?xml version="1.0" encoding="UTF-8"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.krishantha.sample</groupId>
  <artifactId>MavenParentProject</artifactId>
  <version>1.0.0</version>
  <packaging>pom</packaging>
  <name>MavenParentProject</name>
  <description>MavenParentProject</description>
  <modules>
    <module>MediatorSampleProject</module>
    <module>SampleMediator</module>
  </modules>
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-eclipse-plugin</artifactId>
        <version>2.9</version>
        <configuration>
          <buildcommands />
          <projectnatures>
            <projectnature>org.wso2.developerstudio.eclipse.mavenmultimodule.project.nature</projectnature>
          </projectnatures>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

类介体代码：

package com.wso2;

import org.apache.synapse.ManagedLifecycle;
import org.apache.synapse.MessageContext;
import org.apache.synapse.core.SynapseEnvironment;
import org.apache.synapse.mediators.AbstractMediator;

public class FastTrackMediator extends AbstractMediator implements ManagedLifecycle { 

    public boolean mediate(MessageContext messageContext) {
        log.info("Hello, world!");

        return true;
    }

    public void init(SynapseEnvironment synapseEnvironment) {

    }

    public void destroy() {

    }
}

创建了jar文件

Krishanthas-MacBook-Pro:MavenParentProject krishantha$ find . -iname *.jar 
./SampleMediator/target/SampleMediator-1.0.0.jar
Krishanthas-MacBook-Pro:MavenParentProject krishantha$ 

项目结构应如下所示