Using the code, and query memory jvm memory

"C:\Program Files\Java\jdk1.8.0_181\bin\java.exe" "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2019.1.3\lib\idea_rt.jar=60806:C:\Program Files\JetBrains\IntelliJ IDEA 2019.1.3\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_181\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_181\jre\lib\rt.jar;C:\Users\yzmao\Desktop\zn_wifi_crack-master\target\classes;C:\repository\org\springframework\spring-core\4.3.14.RELEASE\spring-core-4.3.14.RELEASE.jar" com.znkeji.zn_wifi_carck.myApp
JVM内存已用的空间为：3 MB
JVM内存的空闲空间为：118 MB
JVM总内存空间为：121 MB
JVM总内存空间为：1776 MB
======================================
操作系统的版本：Windows 10
操作系统物理内存已用的空间为：1567 MB
操作系统物理内存的空闲空间为：6419 MB
操作系统总物理内存：7986 MB
获得线程总数:

 

 

com.sun.management.OperatingSystemMXBean Import; 

Import java.lang.management.ManagementFactory; 

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

// class memory where the virtual machine queries 
        Long vmFree = 0; 
        Long vmUse 0 =; 
        Long vmTotal = 0; 
        Long VMmax = 0; 
        int byteToMb = 1024 * 1024; 
        the Runtime Runtime.getRuntime RT = (); 
        vmTotal rt.totalMemory = () / byteToMb; 
        vmFree rt.freeMemory = () / byteToMb; 
        VMmax rt.maxMemory = () / byteToMb; 
        vmUse = vmTotal - vmFree;  
        System.out.println ( "JVM memory space has been used is:" + vmUse + "MB" );
        System.out.println ( "the JVM memory free space is:" + vmFree + "MB" );
        System.out.println ( "JVM total memory space:" + + vmTotal "MB"); 
        System.out.println ( "JVM total memory space:" VMmax + + "MB"); 
        System.out.println ( "======================================"); 
        // query the operating system level memory conditions 
        = osmxb the OperatingSystemMXBean (the OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean (); 
        String the System.getProperty OS = ( "The os.name"); 
        Long physicalFree osmxb.getFreePhysicalMemorySize = () / byteToMb; 
        Long physicalTotal osmxb.getTotalPhysicalMemorySize = () / byteToMb; 
        Long physicalUse physicalTotal = - physicalFree;  
        the System.out.println ( "operating system version:" + os);
        System.out.println ( "OS physical memory space has been used is:" + physicalFree + "MB" );
        System.out.println ( "OS physical memory free space is:" + physicalUse + "MB" );
        System.out.println ( "total physical memory the operating system:" + physicalTotal + "MB"); 
        // get the total number of threads 
        ThreadGroup parentThread; 
        int totalThread = 0; 
        for (parentThread = Thread.currentThread () getThreadGroup ();. 
             ParentThread ! .getParent () = null; parentThread = parentThread.getParent ()) { 
            totalThread parentThread.activeCount = ();} 
        System.out.println ( "total number of threads is obtained:" + totalThread);} 


    }