think in java(1)

 

java信息

java代码

package com.better.test;

import java.util.Date;
import java.util.Properties;

public class PrintSystemInfo {
    public static void main(String[] args) {
        System.out.println(new Date());
        
        Properties properties = System.getProperties();
        properties.list(System.out);
        
        System.out.println("-------Memory usage:");
        
        Runtime runtime = Runtime.getRuntime();
        
        // 返回java內存的总能量，以字节为单位
        // 1k = 1024字节
        // 1M = 1024k
        // 1G=1024M
        int m = 1024 * 1024;
        System.out.println("Total Memory:" + runtime.totalMemory()/m + "M");
        System.out.println("freeMemory:" + runtime.freeMemory()/m + "M");
    }
}

运行结果

Thu Sep 27 19:47:05 CST 2018
-- listing properties --
java.runtime.name=Java(TM) SE Runtime Environment
sun.boot.library.path=C:\Program Files\Java\jre1.8.0_144\bin
java.vm.version=25.144-b01
java.vm.vendor=Oracle Corporation
java.vendor.url=http://java.oracle.com/
path.separator=;
java.vm.name=Java HotSpot(TM) 64-Bit Server VM
file.encoding.pkg=sun.io
user.script=
user.country=GB
sun.java.launcher=SUN_STANDARD
sun.os.patch.level=
java.vm.specification.name=Java Virtual Machine Specification
user.dir=C:\Users\julius j zhu\eclipse-workspa...
java.runtime.version=1.8.0_144-b01
java.awt.graphicsenv=sun.awt.Win32GraphicsEnvironment
java.endorsed.dirs=C:\Program Files\Java\jre1.8.0_144\li...
os.arch=amd64
java.io.tmpdir=C:\Users\JULIUS~1\AppData\Local\Temp\
line.separator=

java.vm.specification.vendor=Oracle Corporation
user.variant=
os.name=Windows 10
sun.jnu.encoding=GBK
java.library.path=C:\Program Files\Java\jre1.8.0_144\bi...
java.specification.name=Java Platform API Specification
java.class.version=52.0
sun.management.compiler=HotSpot 64-Bit Tiered Compilers
os.version=10.0
user.home=C:\Users\julius j zhu
user.timezone=Asia/Shanghai
java.awt.printerjob=sun.awt.windows.WPrinterJob
file.encoding=GBK
java.specification.version=1.8
user.name=Julius J Zhu
java.class.path=C:\Program Files\Java\jre1.8.0_144\li...
java.vm.specification.version=1.8
sun.arch.data.model=64
java.home=C:\Program Files\Java\jre1.8.0_144
sun.java.command=com.better.test.PrintSystemInfo
java.specification.vendor=Oracle Corporation
user.language=en
awt.toolkit=sun.awt.windows.WToolkit
java.vm.info=mixed mode
java.version=1.8.0_144
java.ext.dirs=C:\Program Files\Java\jre1.8.0_144\li...
sun.boot.class.path=C:\Program Files\Java\jre1.8.0_144\li...
java.vendor=Oracle Corporation
file.separator=\
java.vendor.url.bug=http://bugreport.sun.com/bugreport/
sun.cpu.endian=little
sun.io.unicode.encoding=UnicodeLittle
sun.desktop=windows
sun.cpu.isalist=amd64
-------Memory usage:
Total Memory:192937984M
freeMemory:181M