JMX简介
JMX(Java Management Extensions)是一个为应用程序植入管理功能的框架。JMX是一套标准的代理和服务,实际上,用户可以在任何Java应用程序中使用这些代理和服务实现管理。这是官方文档上的定义,我看过很多次也无法很好的理解。我个人的理解是JMX让程序有被管理的功能,例如你开发一个WEB网站,它是在24小时不间断运行,那么你肯定会对网站进行监控,如每天的UV、PV是多少;又或者在业务高峰的期间,你想对接口进行限流,就必须去修改接口并发的配置值。
JMX架构图
案例:
Mbean
package com.hpe.jmx;
//MBean接口
public interface HelloMBean {
public String getName();
public void setName(String name);
public String getAge();
public void setAge(String age);
public String helloWorld();
public void helloWorld(String str);
public void getTelephone();
}
package com.hpe.jmx;
import java.security.PublicKey;
//Mbean的实现
public class Hello implements HelloMBean {
private String name;
private String age;
public Hello(String name,String age){
this.name = name;
this.age = age;
}
public void getTelephone() {
System.out.println("get Telephone");
}
public String helloWorld() {
System.out.println("hello world");
return "gaojy";
}
public void helloWorld(String str) {
System.out.println("helloWorld:" + str);
}
public String getName() {
System.out.println("get name 123");
return name;
}
public void setName(String name) {
System.out.println("set name 123");
this.name = name;
}
public String getAge() {
System.out.println("get age 123");
return age;
}
public void setAge(String age) {
System.out.println("set age 123");
this.age = age;
}
}
适配层:MBeanServer,主要是提供对资源的注册和管理。
接入层:提供远程访问的入口。
package com.hpe.jmx;
import java.lang.management.ManagementFactory;
import java.rmi.registry.LocateRegistry;
import javax.management.JMException;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import javax.management.remote.JMXConnectorServer;
import javax.management.remote.JMXConnectorServerFactory;
import javax.management.remote.JMXServiceURL;
public class helloAgent {
public static void main(String[] args) throws JMException, Exception {
//适配层
MBeanServer server = ManagementFactory.getPlatformMBeanServer();
ObjectName helloName = new ObjectName("jmxBean:name=hello");
// create mbean and register mbean
//创建并注册Mbean
server.registerMBean(new Hello("gaojy","24"), helloName);
try {
//这个步骤很重要,注册一个端口,绑定url后用于客户端通过rmi方式连接JMXConnectorServer
LocateRegistry.createRegistry(9999);
// URL路径的结尾可以随意指定,但如果需要用Jconsole来进行连接,则必须使用jmxrmi
JMXServiceURL url = new JMXServiceURL
("service:jmx:rmi:///jndi/rmi://localhost:9999/jmxrmi");
JMXConnectorServer jcs = JMXConnectorServerFactory.newJMXConnectorServer(url, null, server);
System.out.println("begin rmi start");
jcs.start();
System.out.println("rmi start");
} catch (Exception e) {
// TODO: handle exception
}
Thread.sleep(60 * 60 * 1000);
}
}
客户端:
package com.hpe.jmx;
import java.io.IOException;
import java.net.MalformedURLException;
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.MBeanServerInvocationHandler;
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 Client {
public static void main(String[] args) throws Exception {
JMXServiceURL url = new JMXServiceURL(
"service:jmx:rmi:///jndi/rmi://localhost:9999/jmxrmi");
JMXConnector jmxc = JMXConnectorFactory.connect(url, null);
MBeanServerConnection mbsc = jmxc.getMBeanServerConnection();
// ObjectName的名称与前面注册时候的保持一致
ObjectName mbeanName = new ObjectName("jmxBean:name=hello");
System.out.println("Domains ......");
String[] domains = mbsc.getDomains();
for (int i = 0; i < domains.length; i++) {
System.out.println("doumain[" + i + "]=" + domains[i]);
}
System.out.println("MBean count = " + mbsc.getMBeanCount());
// 设置指定Mbean的特定属性值
// 这里的setAttribute、getAttribute操作只能针对bean的属性
// 例如对getName或者setName进行操作,只能使用Name,需要去除方法的前缀
mbsc.setAttribute(mbeanName, new Attribute("Name", "杭州"));// 远程设置
mbsc.setAttribute(mbeanName, new Attribute("Age", "1990"));
String age = (String) mbsc.getAttribute(mbeanName, "Age"); // 远程获取
String name = (String) mbsc.getAttribute(mbeanName, "Name");
System.out.println("age=" + age + ";name=" + name);
// 远程方法调用
HelloMBean proxy = MBeanServerInvocationHandler.newProxyInstance(mbsc,
mbeanName, HelloMBean.class, false);
proxy.helloWorld();
proxy.helloWorld("migu");
proxy.getTelephone();
// invoke调用bean的方法,只针对非设置属性的方法
// 例如invoke不能对getName方法进行调用
mbsc.invoke(mbeanName, "getTelephone", null, null);
mbsc.invoke(mbeanName, "helloWorld",
new String[] { "I'll connect to JMX Server via client2" },
new String[] { "java.lang.String" });
mbsc.invoke(mbeanName, "helloWorld", null, null);
}
}
参考
http://www.cnblogs.com/dongguacai/p/5900507.html