扩展 Spring 的 JMX 支持

package com.claudeduguay.mbeans.spring;

import java.lang.reflect.*;

import javax.management.*;
import javax.management.modelmbean.*;

public class ModelMBeanExtension extends RequiredModelMBean
{
  protected NotificationInfoMap notificationInfoMap;
  protected ModelMBeanInfo modelMBeanInfo;
  protected Object managedBean;
  
  public ModelMBeanExtension() throws MBeanException {}

  public ModelMBeanExtension(ModelMBeanInfo modelMBeanInfo)
    throws MBeanException
  {
    super(modelMBeanInfo);
    this.modelMBeanInfo = modelMBeanInfo;
    notificationInfoMap = new NotificationInfoMap(modelMBeanInfo);
  }
  
  public void setModelMBeanInfo(ModelMBeanInfo modelMBeanInfo)
    throws MBeanException
  {
    this.modelMBeanInfo = modelMBeanInfo;
    notificationInfoMap = new NotificationInfoMap(modelMBeanInfo);
    super.setModelMBeanInfo(modelMBeanInfo);
  }
  
  public MBeanNotificationInfo[] getNotificationInfo()
  {
    return modelMBeanInfo.getNotifications();
  }
  
  public void setManagedResource(Object managedBean, String type)
    throws MBeanException, RuntimeOperationsException,
      InstanceNotFoundException, InvalidTargetObjectTypeException
  {
    super.setManagedResource(managedBean, type);
    this.managedBean = managedBean;
  }
  
  protected void maybeSendMethodNotification(
  	String type, String name) throws MBeanException
  {
    MBeanNotificationInfo info = notificationInfoMap.
      findNotificationInfo(type, name);
    if (info != null)
    {
      long timeStamp = System.currentTimeMillis();
      String notificationType = ModelMBeanUtil.
        matchType(info, "." + type + "." + name);
      sendNotification(new Notification(
        notificationType, this, timeStamp,
        info.getDescription()));
    }
  }

  protected void maybeSendAttributeNotification(
    Attribute attribute)
    throws MBeanException, AttributeNotFoundException,
    InvalidAttributeValueException, ReflectionException
  {
    String name = attribute.getName();
    MBeanNotificationInfo info = notificationInfoMap.
      findNotificationInfo("set", attribute.getName());
    if (info != null)
    {
      Object oldValue = getAttribute(name);
      Object newValue = attribute.getValue();
      long timeStamp = System.currentTimeMillis();
      String notificationType = ModelMBeanUtil.
        matchType(info, ".set." + name);
      sendNotification(new AttributeChangeNotification(
        this, timeStamp, timeStamp,
        info.getDescription(), info.getName(),
        notificationType, oldValue, newValue));
    }
  }
  
  public Object invoke(
  	String name, Object[] args, String[] signature)
      throws MBeanException, ReflectionException
  {
    maybeSendMethodNotification("before", name);
    Object returnValue = super.invoke(name, args, signature);
    maybeSendMethodNotification("after", name);
    return returnValue;
  }

  public Object getAttribute(String name) throws MBeanException,
    AttributeNotFoundException, ReflectionException
  {
    try
    {
      Method method = ModelMBeanUtil.findGetMethod(
        modelMBeanInfo, managedBean, name);
      return method.invoke(managedBean, new Object[] {});
    }
    catch (IllegalAccessException e)
    {
      throw new MBeanException(e);
    }
    catch (InvocationTargetException e)
    {
      throw new MBeanException(e);
    }
  }

  public void setAttribute(Attribute attribute)
    throws MBeanException, AttributeNotFoundException,
      InvalidAttributeValueException, ReflectionException
  {
    try
    {
      Method method = ModelMBeanUtil.findSetMethod(
        modelMBeanInfo, managedBean, attribute.getName());
      method.invoke(managedBean, attribute.getValue());
      maybeSendAttributeNotification(attribute);
    }
    catch (InvocationTargetException e)
    {
      throw new MBeanException(e);
    }
    catch (IllegalAccessException e)
    {
      throw new MBeanException(e);
    }
  }
}

package com.claudeduguay.mbeans.spring;

import javax.management.*;
import javax.management.modelmbean.*;

import org.springframework.jmx.export.*;
import org.springframework.jmx.export.assembler.*;

public class MBeanDescriptorEnabledExporter extends MBeanExporter
{
  protected MBeanInfoAssembler mBeanInfoAssembler;
  
  public MBeanDescriptorEnabledExporter()
  {
    setAssembler(new MBeanDescriptorBasedAssembler());
  }
  
  public ModelMBean createModelMBean() throws MBeanException
  {
    if (mBeanInfoAssembler instanceof MBeanDescriptorBasedAssembler)
    {
      return new ModelMBeanExtension();
    }
    return super.createModelMBean();
  }
  
  public void setAssembler(MBeanInfoAssembler mBeanInfoAssembler)
  {
    this.mBeanInfoAssembler = mBeanInfoAssembler;
    super.setAssembler(mBeanInfoAssembler);
  }
}

package com.claudeduguay.mbeans.spring;

import java.io.*;

import javax.management.modelmbean.*;

import org.springframework.core.io.*;
import org.springframework.jmx.export.assembler.*;

import com.claudeduguay.mbeans.model.*;

public class MBeanDescriptorBasedAssembler
  implements MBeanInfoAssembler
{
  public ModelMBeanInfo getMBeanInfo(
    Object managedBean, String beanKey)
  {
    String name = managedBean.getClass().getName();
    String path = name.replace('.', '/') + ".mbean.xml";
    
    ClassPathResource resource = new ClassPathResource(path);
    InputStream input = null;
    try
    {
      input = resource.getInputStream();
      MBeanDescriptor descriptor = MBeanDescriptorUtil.read(input);
      return descriptor.createMBeanInfo();
    }
    catch (Exception e)
    {
      throw new IllegalStateException(
        "Unable to load resource: " + path);
    }
    finally
    {
      if (input != null)
      {
        try { input.close(); } catch (Exception x) {}
      }
    }
  }
}

package com.claudeduguay.jmx.demo.server;

public class ExampleService
{
  protected String propertyValue = "default value";
  
  public ExampleService() {}
  
  public String getPropertyValue()
  {
    System.out.println("ExampleService: Get Property Value");
    return propertyValue;
  }

  public void setPropertyValue(String propertyValue)
  {
    System.out.println("ExampleService: Set Property Value");
    this.propertyValue = propertyValue;
  }

  public void startService()
  {
    System.out.println("ExampleService: Start Service Called");
  }

  public void stopService()
  {
    System.out.println("ExampleService: Stop Service Called");
  }
}

<?xml version="1.0"?>
<mbean name="ExampleService" description="Example Service"
  type="com.claudeduguay.jmx.demo.server.ExampleService">

  <attribute name="propertyValue"
    description="Property Value Access" type="java.lang.String"
    readable="true" writable="true" />

  <operation name="stopService"
    description="Stop Example Service" />
  <operation name="startService"
    description="Start Example Service" />

  <notification name="PropertyValueSet"
    types="example.service.set.propertyValue"
    description="PropertyValue was set" />
  <notification name="BeforeStartService"
    types="example.service.before.startService"
    description="Example Service is Starting" />
  <notification name="AfterStartService"
    types="example.service.after.startService"
    description="Example Service is Started" />
  <notification name="BeforeStopService"
    types="example.service.before.stopService"
    description="Example Service is Stopping" />
  <notification name="AfterStopService"
    types="example.service.after.stopService"
    description="Example Service is Stopped" />
  
</mbean>

package com.claudeduguay.jmx.demo.server;

import org.springframework.context.*;
import org.springframework.context.support.*;

import mx4j.tools.adaptor.http.*;

/*
 * To use the SpringJmxServer, use the following command line
 * arguments to activate the Java 1.5 JMX Server.
 * 
 * -Dcom.sun.management.jmxremote.port=8999
 * -Dcom.sun.management.jmxremote.ssl=false
 * -Dcom.sun.management.jmxremote.authenticate=false
 */

public class SpringJmxServer
{
  public static void main(String[] args)
    throws Exception
  {
    String SPRING_FILE =
      "com/claudeduguay/jmx/demo/server/SpringJmxServer.xml";
    ApplicationContext context =
      new ClassPathXmlApplicationContext(SPRING_FILE);
    HttpAdaptor httpAdaptor =
      (HttpAdaptor)context.getBean("HttpAdaptor");
    httpAdaptor.start();
  }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
  "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
  <bean id="exporter" class=
    "com.claudeduguay.mbeans.spring.MBeanDescriptorEnabledExporter">
    <property name="beans">
      <map>
        <entry key="Services:name=ExampleService"
          value-ref="ExampleService" />
        <entry key="MX4J:name=HttpAdaptor"
          value-ref="HttpAdaptor" />
        <entry key="MX4J:name=XSLTProcessor"
          value-ref="XSLTProcessor" />
      </map>
    </property>
  </bean>
  
  <bean id="XSLTProcessor"
    class="mx4j.tools.adaptor.http.XSLTProcessor" />
  <bean id="HttpAdaptor"
    class="mx4j.tools.adaptor.http.HttpAdaptor">
    <property name="processor" ref="XSLTProcessor"/>
    <property name="port" value="8080"/>
  </bean>
  
  <bean id="ExampleService"
    class="com.claudeduguay.jmx.demo.server.ExampleService" />

</beans>

package com.claudeduguay.jmx.demo.client;

import java.util.*;

import javax.management.*;
import javax.management.remote.*;

public class SpringJmxClient implements NotificationListener
{
  public void handleNotification(
    Notification notification, Object handback) 
  {
    System.out.println(
      "Notification: " + notification.getMessage());
  }
  
  public static void main(String[] args)
    throws Exception
  {
    SpringJmxClient listener = new SpringJmxClient();
    
    String address =
      "service:jmx:rmi:///jndi/rmi://localhost:8999/jmxrmi";
    JMXServiceURL serviceURL = new JMXServiceURL(address);
    Map<String,Object> environment = null;
    JMXConnector connector =
      JMXConnectorFactory.connect(serviceURL, environment);
    MBeanServerConnection mBeanConnection =
      connector.getMBeanServerConnection();
    
    ObjectName exampleServiceName =
      ObjectName.getInstance("Services:name=ExampleService");
    mBeanConnection.addNotificationListener(
      exampleServiceName, listener, null, null);
    
    mBeanConnection.invoke(
      exampleServiceName, "startService", null, null);
    mBeanConnection.setAttribute(exampleServiceName,
      new Attribute("propertyValue", "new value"));
    System.out.println(mBeanConnection.getAttribute(
      exampleServiceName, "propertyValue"));
    mBeanConnection.invoke(
      exampleServiceName, "stopService", null, null);
  }
} 

Claude 是 Capital Stream Inc 的高级 J2EE 架构师。他有超过 25 年的软件开发经验，并且在 Java 平台的第一个 beta 版本发布时就开始使用它了。Claude 已发表了超过 75 篇文章和 超过 150 篇书评，主要关注 Java 语言和 XML。