Getting started with JMX, MBean, mxbean, mbeanserver

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One 、 Concept

1.JMX

Baidu Encyclopedia's explanation is ：

JMX（Java Management Extensions, namely Java Manage extensions ） Is an application for 、 equipment 、 System and other embedded management function framework .JMX It can span a series of heterogeneous operating system platforms 、 System architecture and network transmission protocol , Flexible development of seamless integrated systems 、 Network and service management applications .

Popular point theory ：

JMX It's a JDK The framework provided , Used to manage detection Java Program , Provide for the right to Java Applications and JVM Monitoring and management functions .

JMX adopt MBean、MXBean、MBeanServer To achieve the right java Procedure management

2.MBean

MBean It's a normative JavaBean, It integrates and implements a set of standard Bean Interface , such bean It's called MBean,Mbean Need to register to MBeanServer Managed in .

Usage specification ： You need to define a name that ends with MBean The interface of , for example ： Create a StudentMBean Interface , Then the name of the implementation class of this interface must be Student, At this time Student Of bean Namely MBean.

3.MXBean

MXBean yes MBean Generalized variant of ,MXBean And MBean The main difference is that some custom types of classes will be referenced in the interface （ Non native types ,int、String etc. ）, When JMX Use this MXBean when , This custom type class will be converted to a standard type ,CompositeDataSupport class .

Usage specification ： It and MBean The usage specification of is the same , Only the name of the interface ends with MXBean

It should be noted that ： If your MXBean I have defined the constructor with parameters （ The nonparametric structure is covered ）, Will report a mistake ：

Do not know how to make a JavaFTP.Book from a CompositeData: no method from(CompositeData); no constructor has @ConstructorProperties annotation; does not have a public no-arg constructor; not an interface

The solution is ： Manually add a parameterless constructor

4.MBeanServer

MBeanServer yes JMX The core manager of the agent layer , all MBean All need to MBeanServer register , All right MBean All operations are passed MBeanServer To perform the .
stay MBeanServer in , every last MBean There is a unique sign ObjectName Bind to it .

Two 、 Code example

1.MBean

Define a MBean Interface

public interface StudentMBean {
    
    public int getAge();
    public String getName();
    public String getEmail();
    public void setEmail(String email);
    public String sayHello();
}

Implementation class , That is to say MBean

public class Student implements StudentMBean {
    

    private final int age;
    private final String name;
    private String email;

    public Student(int age, String name, String email) {
    
        this.age = age;
        this.name = name;
        this.email = email;
    }

    @Override
    public int getAge() {
    
        return age;
    }

    @Override
    public String getName() {
    
        return name;
    }

    @Override
    public String getEmail() {
    
        return email;
    }

    @Override
    public void setEmail(String email) {
    
        this.email = email;
    }

    @Override
    public String sayHello() {
    
        return "hello " + name;
    }

}

Test class ：

public class MBeanServerTest {
    

    public static void main(String[] args) throws MalformedObjectNameException, NotCompliantMBeanException, InstanceAlreadyExistsException, MBeanRegistrationException, InterruptedException {
    
        MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer();
        ObjectName student_objectName = new ObjectName("com.liqiye.jmx.mbean:type=Student");
        Student student = new Student(26,"liqiye","[email protected]");
        mBeanServer.registerMBean(student, student_objectName);
        Thread.sleep(Long.MAX_VALUE);
    }

}

function main After the method , Open you up JDK Of /bin Catalog Under the jconsole.exe

You can see that there is java When the program is executed JDK Built in MBean, And what we just defined Student This MBean

2.MXBean

Define a MXBean Interface

public interface TeacherMXBean {
    
    public int getAge();
    public String getName();
    public String getEmail();
    public void setEmail(String email);
    public String sayHello();

    public List<Book> getBook();
    public void addBook(Book book);
}

Implementation class , That is to say MXBean

public class Teacher implements TeacherMXBean {
    

    private final int age;
    private final String name;
    private String email;

    private List<Book> books;

    public Teacher(int age, String name, String email) {
    
        this.age = age;
        this.name = name;
        this.email = email;
        this.books = new ArrayList<>();
    }

    @Override
    public int getAge() {
    
        return age;
    }

    @Override
    public String getName() {
    
        return name;
    }

    @Override
    public String getEmail() {
    
        return email;
    }

    @Override
    public void setEmail(String email) {
    
        this.email = email;
    }

    @Override
    public String sayHello() {
    
        return "hello " + name;
    }

    @Override
    public List<Book> getBook() {
    
        return books;
    }

    @Override
    public void addBook(Book book) {
    
        books.add(book);
    }
}

Test class ：

public class MBeanServerTest {
    

    public static void main(String[] args) throws MalformedObjectNameException, NotCompliantMBeanException, InstanceAlreadyExistsException, MBeanRegistrationException, InterruptedException {
    
        MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer();
ObjectName("com.liqiye.jmx.mbean:type=Student");
        ObjectName teacher_objectName = new ObjectName("com.liqiye.jmx.mxbean:type=Teacher");
        Book book = new Book("java book ", 30L);
        Teacher teacher = new Teacher(27, " Xiao Qi ", "11");
        teacher.addBook(book);
        mBeanServer.registerMBean(teacher, teacher_objectName);
        Thread.sleep(Long.MAX_VALUE);
    }

}

jconsole Can be seen in MXBean There is Book The properties of this custom class , And can get the value inside

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summary

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