java-jmx使用，java高级面试笔试题

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先粘一段内容

 

 

1、程序初哥一般是写死在程序中，到要改变的时候就去修改代码，然后重新编译发布。

2、程序熟手则配置在文件中（JAVA一般都是properties文件），到要改变的时候只要修改配置文件，但还是必须重启系统，以便读取配置文件里最新的值。

3、程序好手则会写一段代码，把配置值缓存起来，系统在获取的时候，先看看配置文件有没有改动，如有改动则重新从配置里读取，否则从缓存里读取。

4、程序高手则懂得物为我所用，用JMX把需要配置的属性集中在一个类中，然后写一个MBean，再进行相关配置。另外JMX还提供了一个工具页，以方便我们对参数值进行修改。

 

JMX的全称为Java Management Extensions. 顾名思义，是管理Java的一种扩展。这种机制可以方便的管理正在运行中的Java程序。常用于管理线程，内存，日志Level，服务重启，系统环境等。

jmx整体架构:

1, Mbean准备

1, 先建立需要连接的接口

 

package com.wenbronk.le.iris.jmx;

/**

 * 实现接口, 可在jconsoler中调用属性

 */

public interface HelloMBean {

    public String getName();

    public void setName(String name);

    public String getAge();

    public void setAge(String age);

    public void helloWorld();

    public void helloWorld(String str);

    public void getTelephone();

}

 

2, 实体类继承

 

package com.wenbronk.le.iris.jmx;

import ch.qos.logback.core.joran.spi.NoAutoStart;

import lombok.AllArgsConstructor;

import lombok.NoArgsConstructor;

/**

 * 必须实现 Mbean, 才可以进行注册

 */

@NoArgsConstructor

@AllArgsConstructor

public class Hello implements HelloMBean {

    private String name;

    private String age;

    @Override

    public String getName() {

        System.out.println("get name::" + name);

        return name;

    }

    @Override

    public void setName(String name) {

        this.name = name;

        System.out.println("set name  " + name);

    }

    @Override

    public String getAge() {

        System.out.println("get age::" + age);

        return age;

    }

    @Override

    public void setAge(String age) {

        this.age = age;

        System.out.println("set age  " + age);

    }

    @Override

    public void helloWorld() {

        System.out.println("hello world");

    }

    @Override

    public void helloWorld(String str) {

        System.out.println("hello world " + str);

    }

    @Override

    public void getTelephone() {

        System.out.println("get telephone");

    }

}

 

2, 使用java命令行指定

3,

 

package com.wenbronk.le.iris.jmx.local;

import com.wenbronk.le.iris.jmx.Hello;

import org.junit.Test;

import javax.management.*;

import java.lang.management.ManagementFactory;

public class HelloAgent {

    public static void main(String[] args) throws MalformedObjectNameException, NotCompliantMBeanException, InstanceAlreadyExistsException, MBeanRegistrationException, InterruptedException {

        MBeanServer server = ManagementFactory.getPlatformMBeanServer();

        Hello hello = new Hello();

        // com.le.iris:type=ZhixinSource/QPS  域名：name=MBean名称

        ObjectName helloName  = new ObjectName("com.wenbronk.le.jmxBean:name=" + hello.getClass().getName());

        ObjectInstance objectInstance = server.registerMBean(hello, helloName);

        Thread.sleep(60*1000*1000);

    }

}

 

需要添加password等, 并指定权限

jmx.access

 

monitor readonly

admin readwrite

 

jmx.password

 

monitor com.le.big

admin com.le.big

 

启动参数指定:

 

JMX_PORT=12345

JAVA_OPTS="-server 

 -Dcom.sun.management.jmxremote

 -Dcom.sun.management.jmxremote.authenticate=true

 -Dcom.sun.management.jmxremote.password.file=jmx.password

 -Dcom.sun.management.jmxremote.access.file=jmx.access

 -Dcom.sun.management.jmxremote.ssl=false

 -Dcom.sun.management.jmxremote.port=${JMX_PORT}

 -Dcom.sun.management.jmxremote.local.only=false

 -Djava.rmi.server.hostname=${IP}

 -Diris.hostname=${IP}

 -Xmx${MEM}m -XX:+UseG1GC -XX:MaxGCPauseMillis=200 -XX:ParallelGCThreads=4

 "



nohup java ${JAVA_OPTS} -jar ${APP_JAR_NAME} ${params} 1>>${APP_HOME}/nohup.log 2>&1 &

 

2, 使用java指定远程连接方式:

3, agentserver的编写

 

package com.wenbronk.le.iris.jmx.remote;

import com.wenbronk.le.iris.jmx.Hello;

import com.wenbronk.le.iris.jmx.Testtt;

import javax.management.MBeanServer;

import javax.management.ObjectInstance;

import javax.management.ObjectName;

import javax.management.remote.JMXConnectorServer;

import javax.management.remote.JMXConnectorServerFactory;

import javax.management.remote.JMXServiceURL;

import java.io.IOException;

import java.lang.management.ManagementFactory;

import java.net.MalformedURLException;

import java.rmi.RemoteException;

import java.rmi.registry.LocateRegistry;

import java.rmi.registry.Registry;

/**

 * 开启后, 可通过jconsoler进行连接

 */

public class HelloAgentRemote {

    public static void main(String[] args) throws Exception {

        MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();

        Hello hello = new Hello("vini", "23");
    // 试了下, name 和 type没啥区别

        ObjectName helloName  = new ObjectName("com.wenbronk.le.jmxBean:name=" + hello.getClass().getSimpleName());

        //ObjectName helloName1  = new ObjectName("com.wenbronk.le.jmxBean:type=" + hello.getClass().getSimpleName());

        Testtt testtt = new Testtt();

        ObjectName testtName = new ObjectName("com.wenbronk.le.jmxBean:type=" + testtt.getClass().getSimpleName());

        //ObjectName testtName1 = new ObjectName("com.wenbronk.le.jmxBean:name=" + testtt.getClass().getSimpleName());

        System.out.println(hello.getClass().getSimpleName());

        ObjectInstance instance = mbs.registerMBean(hello, helloName);

        //ObjectInstance instance3 = mbs.registerMBean(hello, helloName1);

        ObjectInstance instance2 = mbs.registerMBean(testtt, testtName);

        //ObjectInstance instance4 = mbs.registerMBean(testtt, testtName1);

        try {

            // 注册一个端口并绑定

            Registry registry = LocateRegistry.createRegistry(9999);

            JMXServiceURL jmxServiceURL = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://localhost:9999/jmxrmi");

                                                          //service:jmx:rmi:///jndi/rmi://localhost:9999/jmxrmi

            JMXConnectorServer jmxConnectorServer = JMXConnectorServerFactory.newJMXConnectorServer(jmxServiceURL, null, mbs);

            jmxConnectorServer.start();

        }catch (Exception e) {

            e.printStackTrace();

        }

    }

}

 

此时可以通过jconsoler工具进行连接了,

4, 或者自己实现客户端进行连接

 

package com.wenbronk.le.iris.jmx.remote;

import com.wenbronk.le.iris.jmx.HelloMBean;

import javax.management.*;

import javax.management.remote.JMXConnector;

import javax.management.remote.JMXConnectorFactory;

import javax.management.remote.JMXConnectorServerFactory;

import javax.management.remote.JMXServiceURL;

import java.io.IOException;

import java.net.MalformedURLException;

/**

 * 远程连接jmx

 */

public class Client {

    public static void main(String[] args) throws Exception {

        JMXServiceURL jmxServiceURL = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://localhost:9999/jmxrmi");

        JMXConnector connect = JMXConnectorFactory.connect(jmxServiceURL, null);

        MBeanServerConnection mBeanServerConnection = connect.getMBeanServerConnection();

        String[] domains = mBeanServerConnection.getDomains();

        for (int i = 0; i < domains.length; i++) {

            String obj = domains[i];

            System.out.printf("domian[%d] = %s", i, domains[i].toString());

            System.out.println();

        }

        // 注册名和之前server的一致

        ObjectName objectName = new ObjectName("com.wenbronk.le.jmxBean:name=Hello");

        // 获取参数

        getParam(mBeanServerConnection, objectName);

        System.out.println("get params======================");

        // 更改参数

        changeParams(mBeanServerConnection, objectName);

        getParam(mBeanServerConnection, objectName);

        System.out.println("set params======================");

        useMethod(mBeanServerConnection, objectName);

        getParam(mBeanServerConnection, objectName);

        System.out.println("useMethod.========================");

    }

    /**

     * 对method的调用, 采用反射的方式进行

     */

    public static void useMethod(MBeanServerConnection connection, ObjectName objectName) {

        HelloMBean helloMBean = MBeanServerInvocationHandler.newProxyInstance(connection, objectName, HelloMBean.class, true);

        String age = helloMBean.getAge();

        String name = helloMBean.getName();

        helloMBean.setAge("2323223");

        helloMBean.helloWorld("nchar");

    }

    /**

     * 可进行相关参数修改

     * 通过setAttribute、getAttrubute方法来进行操作，则属性的首字母要大写

     */

    public static void changeParams(MBeanServerConnection mBeanServerConnection, ObjectName objectName) throws AttributeNotFoundException, InvalidAttributeValueException, ReflectionException, IOException, InstanceNotFoundException, MBeanException {

        mBeanServerConnection.setAttribute(objectName, new Attribute("Name", "hangzhou"));

        mBeanServerConnection.setAttribute(objectName, new Attribute("Age", "1990"));

    }

    /**

     * 获取参数

     */

    public static void getParam(MBeanServerConnection connection, ObjectName objectName) throws AttributeNotFoundException, MBeanException, ReflectionException, InstanceNotFoundException, IOException {

        String age = (String) connection.getAttribute(objectName, "Age");

        String name = (String) connection.getAttribute(objectName, "Name");

        System.out.println("name " + name + " age: " + age);

    }

}

 

https://www.cnblogs.com/dongguacai/p/5900507.html

 

转载：https://www.cnblogs.com/wenbronk/p/8535103.html

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