运行JMXConnectorFactory.connect时，JMX连接不会重播

问题描述

需要您的帮助以了解为什么我无法使用JMX从客户端应用程序连接到服务器应用程序。我有一个服务器应用程序正在启动一个JMX Bean服务器，一个客户端正在尝试使用JMX连接到该服务器。两个应用程序都在Windows的本地计算机上崩溃。 Jconsole工作正常，我可以将其连接到服务器。但是在运行客户端时，它会“卡住”在线：

  JMXConnector jmxConnector = JMXConnectorFactory.connect(url,null);

应用程序端JMX Server初始化代码：

    MyClass mc = new MyClass ();
    MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
    ObjectName obj = new ObjectName("JMX:name=MyClassJmx");
    mbs.registerMBean(mc,obj);

应用程序端JMX Server JVM参数：

-Dcom.sun.management.jmxremote.port=10090
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false

我与应用程序代码的客户端连接：

  final JMXServiceURL url = new JMXServiceURL("service:jmx:jmxmp://127.0.0.1:10090");
  JMXConnector jmxConnector = JMXConnectorFactory.connect(url,null);
  jmxConnector.connect();

笔记，使用

service：jmx：rmi：/// jndi / rmi：//：10090 / jmxrmi

正在工作。

解决方法

Java reference

JMX消息传递协议（JMXMP）连接器是通用连接器的配置，其中传输协议基于TCP，对象包装是本机Java序列化。安全性比RMI连接器更高。安全性基于Java安全套接字扩展（JSSE），Java身份验证和授权服务（JAAS）和简单身份验证和安全层（SASL）。

通用连接器及其JMXMP配置是可选的，这意味着它们并不总是包含在JMX Remote API的实现中。 J2SE平台不包括可选的通用连接器。

注意–如果要使用JMXMP连接器，请从http://java.sun.com/products/JavaManagement/download.html下载JSR 160参考实现，并将jmxremote_optional.jar文件添加到您的类路径中。

您是否在服务器和客户端类路径中包含jmxremote_optional.jar文件？

我没有使用JMXMP Connector方法的经验，我遵循了JMX文档并尝试通过编写以下示例进行验证，

JMX MBean接口

SystemConfigMBean.java

package jmx.learning;

public interface SystemConfigMBean {

    public void setThreadCount(int noOfThreads);
    public int getThreadCount();
    
    public void setSchemaName(String schemaName);
    public String getSchemaName();
    
    // any method starting with get and set are considered
    // as attributes getter and setter methods,so I am 
    // using do* for operation.
    public String doConfig();
}

用于实现JMX MBean接口的类

SystemConfig.java

package jmx.learning;

public class SystemConfig implements SystemConfigMBean {

    private int threadCount;
    private String schemaName;
    
    public SystemConfig(int numThreads,String schema){
        this.threadCount=numThreads;
        this.schemaName=schema;
    }
    
    @Override
    public void setThreadCount(int noOfThreads) {
        this.threadCount=noOfThreads;
    }


    @Override
    public int getThreadCount() {
        return this.threadCount;
    }


    @Override
    public void setSchemaName(String schemaName) {
        this.schemaName=schemaName;
    }


    @Override
    public String getSchemaName() {
        return this.schemaName;
    }
    
    @Override
    public String doConfig(){
        return "No of Threads="+this.threadCount+" and DB Schema Name="+this.schemaName;
    }

}

使用JMXMP在MBean服务器中创建和注册MBean 连接器

SystemConfigManagement.java

package jmx.learning;

import java.io.IOException;

import javax.management.InstanceAlreadyExistsException;
import javax.management.MBeanRegistrationException;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.MalformedObjectNameException;
import javax.management.NotCompliantMBeanException;
import javax.management.ObjectName;
import javax.management.remote.JMXConnectorServer;
import javax.management.remote.JMXConnectorServerFactory;
import javax.management.remote.JMXServiceURL;

public class SystemConfigManagement {
    private static final int DEFAULT_NO_THREADS = 10;
    private static final String DEFAULT_SCHEMA = "default";

    public static void main(String[] args) throws MalformedObjectNameException,InterruptedException,InstanceAlreadyExistsException,MBeanRegistrationException,NotCompliantMBeanException,IOException {
        // Instantiate the MBean server
        MBeanServer mbs = MBeanServerFactory.createMBeanServer();

        // Create a JMXMP connector server
        JMXServiceURL url = new JMXServiceURL("jmxmp",null,5555);
        JMXConnectorServer cs = JMXConnectorServerFactory
                .newJMXConnectorServer(url,mbs);
        cs.start();

        // register the MBean
        SystemConfig mBean = new SystemConfig(DEFAULT_NO_THREADS,DEFAULT_SCHEMA);
        ObjectName name = new ObjectName("jmx.learning:type=SystemConfig");
        mbs.registerMBean(mBean,name);
        do {
            Thread.sleep(3000);
            System.out.println("Thread Count=" + mBean.getThreadCount()
                    + " Schema Name=" + mBean.getSchemaName());
        } while (mBean.getThreadCount() != 0);

    }
}

JMXMP连接器客户端

SystemConfigManagementClient.java

package jmx.learning;

import java.io.IOException;

import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;

public class SystemConfigManagementClient {
    public static void main(String[] args) {
        JMXConnector jmxc = null;
        try {
            // Create a JMXMP connector client
            System.out.println("\nCreate a JMXMP connector client");
            JMXServiceURL url = new JMXServiceURL(
                    "service:jmx:jmxmp://localhost:5555");
            jmxc = JMXConnectorFactory.connect(url,null);
            // get MBeanServerConnection
            MBeanServerConnection serverConn = jmxc.getMBeanServerConnection();

            ObjectName objectName = new ObjectName(
                    "jmx.learning:type=SystemConfig");

            // Executing doConfig() method
            String value = (String) serverConn.invoke(objectName,"doConfig",new Object[] {},new String[] {});
            System.out.println(value);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (jmxc != null) {
                try {
                    jmxc.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

注意：我已下载jmxremote_optional.jar文件并保存在项目类路径中。

执行：

服务器输出：

d:\Java\jdk1.8.0_261\bin\java.exe -cp .;d:\External_Library\jmxremote_optional.jar jmx.learning.SystemConfigManagement
Thread Count=10 Schema Name=default
Thread Count=10 Schema Name=default

客户端输出：

d:\Java\jdk1.8.0_261\bin\java.exe -cp .;d:\External_Library\jmxremote_optional.jar jmx.learning.SystemConfigManagementClient

Create a JMXMP connector client
No of Threads=10 and DB Schema Name=default

我不确定您编写的服务器代码，看起来该代码正在使用RMIConnector。因此，从客户端使用RMI连接器Java远程方法协议（JRMP）进行连接尝试是可行的。

即使您已经传递了属性-Dcom.sun.management.jmxremote.port=portNum 此属性表示portNum是您要用来启用JMX RMI连接的端口号。

注意：出于演示目的，我没有显示安全处理内容，在真实代码中，这些内容必须存在。

java java jmx jmxmp rmi