mBean 查看ActiveMQ队列中数据数目

[wulathink]

我正在用JAVA 写一个读取ActiveMQ队列中数据数目的程序。经过寻找后再网上找到一段这样的程序
beans.xml如下：

<beans>
<bean class="org.springframework.jmx.support.MBeanServerConnectionFactoryBean" id="mbeanServerConnection">
  <property name="serviceUrl" value="service:jmx:rmi:///jndi/rmi://localhost:1099/jmxrmi">
 </property></bean>

 <bean class="com.sample.QueueSizeCounter" id="queueCounter">
  <property name="mBeanServerConnection" ref="mbeanServerConnection">
 </property></bean>

</beans>

主要的功能实现程序如下

// A class using the MBeanServerConnection to fetch the attribute from the MBean 
package com.sample;

import javax.management.MBeanServerConnection;
import javax.management.ObjectName;

import org.apache.log4j.Logger;

public class QueueSizeCounter {

 private MBeanServerConnection mBeanServerConnection;

 private Logger logger = Logger.getLogger(QueueSizeCounter.class);

 public Long getQueueSize(String queueName) {
  Long queueSize = null;
  try {

   ObjectName objectNameRequest = new ObjectName(
     "org.apache.activemq:BrokerName=localhost,Type=Queue,Destination=" + queueName);

   queueSize = (Long) mBeanServerConnection.getAttribute(objectNameRequest, "QueueSize");

   return queueSize;
  }
  catch (Exception e) {
   logger.error(e.getMessage());
  }
  return queueSize;
 }

 public void setmBeanServerConnection(MBeanServerConnection mBeanServerConnection) {
  this.mBeanServerConnection = mBeanServerConnection;
 }

}

主程序如下

// Running the Queue Counter 
package com.sample;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {

 public static void main(String[] args) {

  ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");// ——  POS1——
  
  QueueSizeCounter queueCounter = (QueueSizeCounter) ctx.getBean("queueCounter");

  String queueName = "Queue1";
  long queueSize = queueCounter.getQueueSize(queueName);

  System.out.println("Size of " + queueName + " : " + queueSize);
 }
}

但是程序总会报出各种莫名其妙的错误，比如在POS1总会说：

引用

the type org.springframework.beans.BeansException can not be resolved. It is indirectly referenced from required .class files

在网上查找后，有人给出答案说这个的原因是类A的实现需要用类B，但是我只import了类A没有importy类B。但是我把这一句改成

ApplicationContext ctx = new ClassPathXmlApplicationContext();

后这一句就没有这样的错误了，错误又跑到其他地方去了……

在spring官网上看ClassPathXmlApplicationContext的构造函数就是这样写的啊：

ClassPathXmlApplicationContext(String A)

请问是哪里的原因呢？