Jconsole分析

Posted 2021-12-07 wylwyl

1、在命令行输入jconsole，然后选择需要连接的进程

2、内存分析

package com.JVM.thread;

import java.util.ArrayList;
import java.util.List;

/**
 * @ClassName JconsoleHeapTest
 * @Description 内存分析
 * @Author Administrator
 * @Date 2019/5/26 14:39
 * @Version 1.0
 **/
public class JconsoleHeapTest {
    public static final int _1MB = 1024*1024;
    public static void main(String[] args) {
        try {
            Thread.sleep(5000);

        } catch (Exception e) {
            e.printStackTrace();
        }

        System.out.println("method start");

        fill(1000);
        System.out.println("method end");

    }

    public static void fill(Integer cnt) {
        List<JconsoleHeapTest> jconsoleHeapTests = new ArrayList<>();
        for(int i = 0; i < cnt; i++) {
            try {
                Thread.sleep(100);
            } catch (Exception e) {
                e.printStackTrace();
            }
            // 不停创建对象
            jconsoleHeapTests.add(new JconsoleHeapTest());
        }
    }
}

　　

 

3、线程死锁分析

package com.JVM.thread;

/**
 * @ClassName JconsoleSyncDeadLockTest
 * @Description 线程死锁分析监控
 * @Author Administrator
 * @Date 2019/5/26 14:30
 * @Version 1.0
 **/
public class JconsoleSyncDeadLockTest {
    private static Object locka = new Object();
    private static Object lockb = new Object();

    public static void main(String[] args) {
        // 线程1
        Thread thread1 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (locka) {
                    try {
                        System.out.println(Thread.currentThread().getName() + "get lockaing");
                        Thread.sleep(500);
                        System.out.println(Thread.currentThread().getName()+" after sleep 500ms!");
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                    System.out.println(Thread.currentThread().getName()+" need lockb!Just waiting!");

                    synchronized (lockb) {
                        System.out.println(Thread.currentThread().getName()+" get lockb ing!");
                    }
                }
            }
        }, "thread1");

        // 线程2
        Thread thread2 = new Thread(new Runnable() {
            @Override
            public void run() {
                synchronized (lockb) {
                    try {
                        System.out.println(Thread.currentThread().getName() + "get lockb ing");
                        Thread.sleep(500);
                        System.out.println(Thread.currentThread().getName()+" after sleep 500ms!");
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                    System.out.println(Thread.currentThread().getName()+" need locka! Just waiting!");

                    synchronized (locka) {
                        System.out.println(Thread.currentThread().getName()+" get locka ing!");
                    }
                }
            }
        }, "thread2");

        thread1.start();
        thread2.start();
    }
}

　　

 

4、线程分析

package com.JVM.thread;

import java.util.Scanner;

/**
 * @ClassName JconsoleThreadTest
 * @Description 线程分析
 * @Author Administrator
 * @Date 2019/5/26 14:19
 * @Version 1.0
 **/
public class JconsoleThreadTest {

    public static final int _1MB = 1024 * 1024;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        sc.next();
        //  控制台输入next，后执行whilleTread线程
        new Thread(() -> {
            System.out.println("start while Thread");
            while(true) {

            }
        }, "whileThread").start();

        sc.next();

        // 控制台再次输入next，后执行waitTread线程
        new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println("start waitThread");
                Object o = new Object();
                synchronized (o) {
                    try {
                        o.wait();
                    } catch (Exception e) {

                    }
                }
            }
        }, "waitThread").start();

    }

}