[探究JMX] 5、动态模型MBean
一、简介
Model MBean是基于DynamicMBean的更实用的MBean，如果编写被管理的类为标准MBean，我们必须为它们实现一套以MBean为后缀名的接口，这样使代码的耦合度增高。而基于Model Mbean，我们可以用配置文件等动态的方式来管理类，被管理的类可以是普通的类，这样也降低了系统的耦合性。
二、准备工作
1、为了Web方式管理MBean，我们引入jmxtools.jar
三、代码实例
package com.muyu.jmx;
public class ConfigModel {
private String configLocation;
public String getConfigLocation() {
return configLocation;
}
public void printConfigLocation() {
System.out.println(configLocation);
}
public void printConfigLocation(String i_ConfigLocation) {
System.out.println(i_ConfigLocation);
}
public void setConfigLocation(String configLocation) {
this.configLocation = configLocation;
}
}
package com.muyu.jmx;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.ObjectName;
import javax.management.modelmbean.RequiredModelMBean;
import javax.management.remote.JMXConnectorServer;
import javax.management.remote.JMXConnectorServerFactory;
import javax.management.remote.JMXServiceURL;
import com.sun.jdmk.comm.HtmlAdaptorServer;
public class ConfigAgent {
public static void main(String[] args) throws Exception {
MBeanServer server = MBeanServerFactory.createMBeanServer();
ObjectName configName = new ObjectName("LuisFigo:name=configModel");
RequiredModelMBean config = ModelMBean.createModelMBean();
server.registerMBean(config, configName);
ObjectName adapterName = new ObjectName("HelloAgent:name=htmladapter,port=8000");
//通过Web来管理MBean
HtmlAdaptorServer adapter = new HtmlAdaptorServer();
adapter.setPort(8000);
server.registerMBean(adapter, adapterName);
adapter.start();
System.out.println("adapter start.....");
//通过RMI方式来管理MBean
Registry registry = LocateRegistry.createRegistry(9999);
JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://localhost:9999/mserver");
JMXConnectorServer cs = JMXConnectorServerFactory.newJMXConnectorServer(url, null, server);
cs.start();
System.out.println("rmi start.....");
}
}
package com.muyu.jmx;
import javax.management.Attribute;
import javax.management.AttributeNotFoundException;
import javax.management.Descriptor;
import javax.management.InstanceNotFoundException;
import javax.management.InvalidAttributeValueException;
import javax.management.MBeanException;
import javax.management.MBeanParameterInfo;
import javax.management.ReflectionException;
import javax.management.RuntimeOperationsException;
import javax.management.modelmbean.DescriptorSupport;
import javax.management.modelmbean.InvalidTargetObjectTypeException;
import javax.management.modelmbean.ModelMBeanAttributeInfo;
import javax.management.modelmbean.ModelMBeanInfo;
import javax.management.modelmbean.ModelMBeanInfoSupport;
import javax.management.modelmbean.ModelMBeanOperationInfo;
import javax.management.modelmbean.RequiredModelMBean;
public class ModelMBean {
private static final boolean READABLE = true;
private static final boolean WRITABLE = true;
private static final boolean IS = true;
private final static String STRING_CLASS = "java.lang.String";
public static RequiredModelMBean createModelMBean() throws RuntimeOperationsException,
MBeanException, InstanceNotFoundException, InvalidTargetObjectTypeException, AttributeNotFoundException, InvalidAttributeValueException, ReflectionException {
RequiredModelMBean modelMBean = null;
modelMBean = new RequiredModelMBean();
modelMBean.setManagedResource(new ConfigModel(), "ObjectReference");
ModelMBeanInfo info = createModelMBeanInfo();
modelMBean.setModelMBeanInfo(info);
modelMBean.setAttribute(new Attribute("ConfigLocation", "test initial"));
return modelMBean;
}
public static ModelMBeanInfo createModelMBeanInfo() {
Descriptor portAttrDesc = new DescriptorSupport();
portAttrDesc.setField("name", "ConfigLocation");
portAttrDesc.setField("descriptorType", "attribute");
portAttrDesc.setField("displayName", "ConfigLocation");
portAttrDesc.setField("getMethod", "getConfigLocation");
portAttrDesc.setField("setMethod", "setConfigLocation");
//属性
ModelMBeanAttributeInfo nameAttrInfo = new ModelMBeanAttributeInfo("ConfigLocation", // 属性名
STRING_CLASS, //属性类型
"luisfigo location", // 描述文字
READABLE, WRITABLE, !IS, // 读写
portAttrDesc
);
//方法
Descriptor getStateDesc = new DescriptorSupport(new String[] {
"name=getConfigLocation", "descriptorType=operation", "class=com.muyu.jmx.ConfigModel",
"role=operation" });
// 构造 setConfigLocation操作描述符信息
Descriptor setStateDesc = new DescriptorSupport(new String[] {
"name=setConfigLocation", "descriptorType=operation", "class=com.muyu.jmx.ConfigModel",
"role=operation" });
ModelMBeanOperationInfo getConfigLocation = new ModelMBeanOperationInfo(
"getConfigLocation",
"get configLocation attribute",
null,
"java.lang.String",
ModelMBeanOperationInfo.ACTION,
getStateDesc
);
MBeanParameterInfo[] setStateParms = new MBeanParameterInfo[] { (new MBeanParameterInfo(
"configLocation_para", "java.lang.String", "new configLocation value")) };
ModelMBeanOperationInfo setConfigLocation = new ModelMBeanOperationInfo(
"setConfigLocation",
"set configLocation attribute",
setStateParms,
"void",
ModelMBeanOperationInfo.ACTION,
setStateDesc
);
ModelMBeanOperationInfo printConfig = new ModelMBeanOperationInfo("printConfigLocation", "控制台输出configLocation信息",
null, "void", ModelMBeanOperationInfo.INFO, null);
ModelMBeanOperationInfo printConfig_1 = null;
MBeanParameterInfo[] params = new MBeanParameterInfo[1];
params[0] = new MBeanParameterInfo("i_ConfigLocation", STRING_CLASS, "Hello , I am LuisFigo");
printConfig_1 = new ModelMBeanOperationInfo("printConfigLocation", "控制台输出configLocation_para信息",
params, "void", ModelMBeanOperationInfo.INFO, null);
ModelMBeanInfo mbeanInfo = new ModelMBeanInfoSupport(//
RequiredModelMBean.class.getName(), // MBean类
"ModelMBeanInfoSupport Dynamic MBean", // 描述文字
new ModelMBeanAttributeInfo[] { // 所有的属性信息（数组）
nameAttrInfo },//只有一个属性
null, // 所有的构造函数信息
new ModelMBeanOperationInfo[] { // 所有的操作信息（数组）
getConfigLocation,
setConfigLocation,
printConfig,
printConfig_1},//
null,
null
);
return mbeanInfo;
}
}
package com.muyu.jmx;
import java.io.IOException;
import java.util.Iterator;
import java.util.Set;
import javax.management.Attribute;
import javax.management.AttributeNotFoundException;
import javax.management.InstanceNotFoundException;
import javax.management.InvalidAttributeValueException;
import javax.management.MBeanException;
import javax.management.MBeanServerConnection;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
public class ConfigClient {
public static void main(String[] args) throws IOException, MalformedObjectNameException, NullPointerException, InstanceNotFoundException, MBeanException, ReflectionException, AttributeNotFoundException, InvalidAttributeValueException {
JMXServiceURL url = new JMXServiceURL(
"service:jmx:rmi:///jndi/rmi://localhost:9999/mserver");
JMXConnector jmxc = JMXConnectorFactory.connect(url, null);
MBeanServerConnection mbsc = jmxc.getMBeanServerConnection();
Set names = mbsc.queryNames(null, null);
for (Iterator i = names.iterator(); i.hasNext();) {
System.out.println("\tObjectName = " + (ObjectName) i.next());
}
ObjectName stdMBeanName = new ObjectName("LuisFigo:name=configModel");
mbsc.invoke(stdMBeanName, "printConfigLocation", new String[]{"helloworld"}, new String[]{"java.lang.String"});
mbsc.setAttribute(stdMBeanName, new Attribute("ConfigLocation", "LuisFigo, this is a new configLocation"));
mbsc.invoke(stdMBeanName, "printConfigLocation", null, null);
jmxc.close();
}
}
说明：
运行ConfigAgent后，在浏览器里输入地址http://localhost:8000/，点击name=configModel后进行configModel MBean管理页面，可以对configMBean进行一些操作，同第二节介绍的标准MBean很相似。运行ConfigClient可以发现，通过RMI可以管理ConfigAgent中注册的MBean。
四、总结
动态ModelMBean实现了被管理类与JMX的解耦，在ModelMBean类里我们可以暴露一些操作和属性。而客户端看起来像什么事都没有发生一样。如果采用JMX来管理系统的话，我们只需要提供一个ModelMBean这样一个管理类就可以，而不需要破坏原来的系统代码，真正实现了系统与JMX的解耦。