Java--获取属性/获取环境变量--System.getProperty/System.getenv

淩亂°似流年 2023-01-24 02:29 8阅读 0赞

原文网址：[Java--获取属性/获取环境变量--System.getProperty/System.getenv\_IT利刃出鞘的博客-CSDN博客][Java--_--System.getProperty_System.getenv_IT_-CSDN]

# 简介 #

**说明**

Java可以在程序中获取属性，也可以获取环境变量（系统变量）。属性与Java程序有关，环境变量与Java所在的系统环境有关。

因此，我们就可以通过在外部指定一些参数来控制程序的运行，也可以在程序中判断当前的环境（比如是Linux还是Windows）等。

获取属性的方法：System.getProperty("属性名")；获取环境变量的方法：System.getenv("环境变量名")。

本文用实例介绍Java在程序中获取属性和获取系统变量的方法。

**属性与环境变量（系统变量）的区别**

<table> 
 <tbody> 
 <tr> 
 <td>项</td> 
 <td>属性</td> 
 <td>环境变量</td> 
 </tr> 
 <tr> 
 <td>运行时是否可修改</td> 
 <td>可以</td> 
 <td>不可以</td> 
 </tr> 
 <tr> 
 <td>有效范围</td> 
 <td>仅在java平台中有效</td> 
 <td>系统里所有程序都有效</td> 
 </tr> 
 <tr> 
 <td>创建的时机</td> 
 <td>打包应用时属性必须存在</td> 
 <td>可以在任何时候创建环境变量</td> 
 </tr> 
 </tbody> 
</table>

# 获取属性 #

## 简介 ##

**常用方法**

<table> 
 <tbody> 
 <tr> 
 <td>方法</td> 
 <td>作用</td> 
 </tr> 
 <tr> 
 <td>System.getProperties()</td> 
 <td>获得所有属性</td> 
 </tr> 
 <tr> 
 <td>System.getProperty(String key)</td> 
 <td>获得名为key的属性的值。</td> 
 </tr> 
 <tr> 
 <td>System.getProperty(String key, String def)</td> 
 <td>获得名为key的属性的值，获取不到则将返回def这个默认值。</td> 
 </tr> 
 </tbody> 
</table>

**自定义属性**

可以在命令行运行jar包时指定属性，例如：-Dpassword=abc123，然后就可以在程序中获取：

package com.example.a;
    
    public class Demo {
        public static void main(String[] args) {
            String password = System.getProperty("password");
            System.out.println(password);
        }
    }

先将程序打包为jar包，再运行它，即可获取到值。（-D必须在-jar之前指定）

## ![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16][]**打印所有的属性** ##

可以通过以下程序获取所有属性：

package com.example.a;
    
    import java.util.Properties;
    
    public class Demo {
        public static void main(String[] args) {
            Properties properties = System.getProperties();
            properties.forEach((key, value) -> {
                System.out.println(key + ":" +value);
            });
        }
    }

执行结果：

sun.cpu.isalist:amd64
    sun.desktop:windows
    sun.io.unicode.encoding:UnicodeLittle
    sun.cpu.endian:little
    java.vendor.url.bug:http://bugreport.sun.com/bugreport/
    file.separator:\
    java.vendor:Oracle Corporation
    sun.boot.class.path:D:\dev\Java\jdk1.8.0_201\jre\lib\resources.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\rt.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\sunrsasign.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\jsse.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\jce.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\charsets.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\jfr.jar;D:\dev\Java\jdk1.8.0_201\jre\classes
    java.ext.dirs:D:\dev\Java\jdk1.8.0_201\jre\lib\ext;C:\WINDOWS\Sun\Java\lib\ext
    java.version:1.8.0_201
    java.vm.info:mixed mode
    awt.toolkit:sun.awt.windows.WToolkit
    user.language:zh
    java.specification.vendor:Oracle Corporation
    sun.java.command:com.example.a.Demo
    java.home:D:\dev\Java\jdk1.8.0_201\jre
    sun.arch.data.model:64
    java.vm.specification.version:1.8
    java.class.path:D:\dev\Java\jdk1.8.0_201\jre\lib\charsets.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\deploy.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\access-bridge-64.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\cldrdata.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\dnsns.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\jaccess.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\jfxrt.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\localedata.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\nashorn.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\sunec.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\sunjce_provider.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\sunmscapi.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\sunpkcs11.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\ext\zipfs.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\javaws.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\jce.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\jfr.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\jfxswt.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\jsse.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\management-agent.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\plugin.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\resources.jar;D:\dev\Java\jdk1.8.0_201\jre\lib\rt.jar;E:\work\Idea_proj\demo_Simple\demo_java\target\production\demo_java;D:\Program Files\JetBrains\IntelliJ IDEA 2021.2\lib\idea_rt.jar
    user.name:Liu
    file.encoding:UTF-8
    java.specification.version:1.8
    java.awt.printerjob:sun.awt.windows.WPrinterJob
    user.timezone:
    user.home:C:\Users\Liu
    os.version:10.0
    sun.management.compiler:HotSpot 64-Bit Tiered Compilers
    java.specification.name:Java Platform API Specification
    java.class.version:52.0
    java.library.path:D:\dev\Java\jdk1.8.0_201\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\Program Files (x86)\Common Files\Oracle\Java\javapath;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;d:\Program Files\Git\cmd;D:\dev\Java\jdk1.8.0_201\bin;E:\work\maven\apache-maven-3.6.3\bin;D:\Program Files\mysql-8.0.21-winx64\bin;E:\work\npm\node_global;D:\dev\nodejs\;D:\dev\bigdata\hadoop-3.2.2\bin;D:\dev\bigdata\scala-2.12-13\bin;C:\Users\Liu\AppData\Local\Microsoft\WindowsApps;D:\Program Files\JetBrains\WebStorm 2021.1.3\bin;;D:\Program Files\dev\nvm\symlink;C:\Users\Liu\AppData\Roaming\npm;;.
    sun.jnu.encoding:GBK
    os.name:Windows 10
    user.variant:
    java.vm.specification.vendor:Oracle Corporation
    java.io.tmpdir:C:\Users\Liu\AppData\Local\Temp\
    line.separator:
    
    java.endorsed.dirs:D:\dev\Java\jdk1.8.0_201\jre\lib\endorsed
    os.arch:amd64
    java.awt.graphicsenv:sun.awt.Win32GraphicsEnvironment
    java.runtime.version:1.8.0_201-b09
    java.vm.specification.name:Java Virtual Machine Specification
    user.dir:E:\work\Idea_proj\demo_Simple\demo_java
    user.country:CN
    user.script:
    sun.java.launcher:SUN_STANDARD
    sun.os.patch.level:
    java.vm.name:Java HotSpot(TM) 64-Bit Server VM
    file.encoding.pkg:sun.io
    path.separator:;
    java.vm.vendor:Oracle Corporation
    java.vendor.url:http://java.oracle.com/
    sun.boot.library.path:D:\dev\Java\jdk1.8.0_201\jre\bin
    java.vm.version:25.201-b09
    java.runtime.name:Java(TM) SE Runtime Environment

## 默认属性及其含义 ##

<table> 
 <tbody> 
 <tr> 
 <td>参数</td> 
 <td>含义</td> 
 </tr> 
 <tr> 
 <td>java.version</td> 
 <td>Java 运行时环境版本&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.vendor</td> 
 <td>Java 运行时环境供应商&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.vendor.url</td> 
 <td>Java 供应商的 URL&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.home</td> 
 <td>Java 安装目录&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.vm.specification.version</td> 
 <td>Java 虚拟机规范版本&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.vm.specification.vendor</td> 
 <td>Java 虚拟机规范供应商&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.vm.specification.name</td> 
 <td>Java 虚拟机规范名称&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.vm.version</td> 
 <td>Java 虚拟机实现版本&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.vm.vendor</td> 
 <td>Java 虚拟机实现供应商&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.vm.name</td> 
 <td>Java 虚拟机实现名称&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.specification.version</td> 
 <td>Java 运行时环境规范版本&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.specification.vendor</td> 
 <td>Java 运行时环境规范供应商&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.specification.name</td> 
 <td>Java 运行时环境规范名称&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.class.version</td> 
 <td>Java 类格式版本号&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.class.path</td> 
 <td>Java 类路径&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.library.path</td> 
 <td>加载库时搜索的路径列表&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.io.tmpdir</td> 
 <td>默认的临时文件路径&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.compiler</td> 
 <td>要使用的 JIT 编译器的名称&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>java.ext.dirs</td> 
 <td>一个或多个扩展目录的路径&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>os.name</td> 
 <td>操作系统的名称&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>os.arch</td> 
 <td>操作系统的架构&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>os.version</td> 
 <td>操作系统的版本&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>file.separator</td> 
 <td>文件分隔符（在 UNIX 系统中是“/” ）</td> 
 </tr> 
 <tr> 
 <td>path.separator</td> 
 <td>路径分隔符（在 UNIX 系统中是“:” ）</td> 
 </tr> 
 <tr> 
 <td>line.separator</td> 
 <td>行分隔符（在 UNIX 系统中是“/n” ）</td> 
 </tr> 
 <tr> 
 <td>user.name</td> 
 <td>用户的账户名称&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>user.home</td> 
 <td>用户的主目录&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td> 
 </tr> 
 <tr> 
 <td>user.dir</td> 
 <td>用户的当前工作目录 &nbsp; &nbsp;</td> 
 </tr> 
 </tbody> 
</table>

# 获取环境变量 #

## 简介 ##

**常用方法**

<table> 
 <tbody> 
 <tr> 
 <td>方法</td> 
 <td>作用</td> 
 </tr> 
 <tr> 
 <td>System.getenv()</td> 
 <td>获得所有环境变量</td> 
 </tr> 
 <tr> 
 <td>System.getenv(String name)</td> 
 <td>获得名为name的属性的值。</td> 
 </tr> 
 </tbody> 
</table>

**获得自定义的环境变量**

现在指定JAVA\_HOME环境变量，值为JDK路径，如下图所示：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_20_color_FFFFFF_t_70_g_se_x_16 1][]

package com.example.a;
    
    public class Demo {
        public static void main(String[] args) {
            String javaHome = System.getenv("JAVA_HOME");
            System.out.println("javaHome的值:" + javaHome);
        }
    }

执行结果（直接执行或者打成jar包来执行都可以）

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASVTliKnliIPlh7rpnpg_size_15_color_FFFFFF_t_70_g_se_x_16][]

## 打印所有的环境变量 ##

package com.example.a;
 
 import java.util.Map;
 
 public class Demo {
 public static void main(String[] args) {
 Map<String, String> envMap = System.getenv();
 for (Map.Entry<String, String> entry : envMap.entrySet()) {
 System.out.println(entry.getKey() + ":" + entry.getValue());
 }
 }
 }

执行结果：

USERDOMAIN_ROAMINGPROFILE:DESKTOP-QI6B9ME
    NVM_SYMLINK:D:\Program Files\dev\nvm\symlink
    PROCESSOR_LEVEL:23
    SESSIONNAME:Console
    ALLUSERSPROFILE:C:\ProgramData
    PROCESSOR_ARCHITECTURE:AMD64
    PSModulePath:C:\Program Files\WindowsPowerShell\Modules;C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules
    SystemDrive:C:
    MAVEN_HOME:E:\work\maven\apache-maven-3.6.3
    MOZ_PLUGIN_PATH:D:\Program Files (x86)\Foxit Software\Foxit Reader\plugins\
    USERNAME:knife
    ProgramFiles(x86):C:\Program Files (x86)
    FPS_BROWSER_USER_PROFILE_STRING:Default
    PATHEXT:.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC
    DriverData:C:\Windows\System32\Drivers\DriverData
    ProgramData:C:\ProgramData
    ProgramW6432:C:\Program Files
    HOMEPATH:\Users\knife
    PROCESSOR_IDENTIFIER:AMD64 Family 23 Model 96 Stepping 1, AuthenticAMD
    HADOOP_HOME:D:\dev\bigdata\hadoop-3.2.2
    M2_HOME:E:\work\maven\apache-maven-3.6.3
    ProgramFiles:C:\Program Files
    PUBLIC:C:\Users\Public
    windir:C:\WINDOWS
    =:::::\
    LOCALAPPDATA:C:\Users\knife\AppData\Local
    USERDOMAIN:DESKTOP-QI6B9ME
    FPS_BROWSER_APP_PROFILE_STRING:Internet Explorer
    LOGONSERVER:\\DESKTOP-QI6B9ME
    JAVA_HOME:D:\dev\Java\jdk1.8.0_201
    WebStorm:D:\Program Files\JetBrains\WebStorm 2021.1.3\bin;
    OneDrive:C:\Users\knife\OneDrive
    APPDATA:C:\Users\knife\AppData\Roaming
    CommonProgramFiles:C:\Program Files\Common Files
    Path:C:\Program Files (x86)\Common Files\Oracle\Java\javapath;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;d:\Program Files\Git\cmd;D:\dev\Java\jdk1.8.0_201\bin;E:\work\maven\apache-maven-3.6.3\bin;D:\Program Files\mysql-8.0.21-winx64\bin;E:\work\npm\node_global;D:\dev\nodejs\;D:\dev\bigdata\hadoop-3.2.2\bin;D:\dev\bigdata\scala-2.12-13\bin;C:\Users\knife\AppData\Local\Microsoft\WindowsApps;D:\Program Files\JetBrains\WebStorm 2021.1.3\bin;;D:\Program Files\dev\nvm\symlink;C:\Users\knife\AppData\Roaming\npm;
    OS:Windows_NT
    COMPUTERNAME:DESKTOP-QI6B9ME
    PROCESSOR_REVISION:6001
    CommonProgramW6432:C:\Program Files\Common Files
    ComSpec:C:\WINDOWS\system32\cmd.exe
    WXDRIVE_START_ARGS:--wxdrive-setting=0 --disable-gpu --disable-software-rasterizer --enable-features=NetworkServiceInProcess
    SystemRoot:C:\WINDOWS
    TEMP:C:\Users\knife\AppData\Local\Temp
    HOMEDRIVE:C:
    USERPROFILE:C:\Users\knife
    TMP:C:\Users\knife\AppData\Local\Temp
    CommonProgramFiles(x86):C:\Program Files (x86)\Common Files
    NUMBER_OF_PROCESSORS:12
    IDEA_INITIAL_DIRECTORY:C:\Users\knife\Desktop

## 默认环境变量及其含义 ##

<table> 
 <tbody> 
 <tr> 
 <td> 环境变量 </td> 
 <td> 含义 </td> 
 </tr> 
 <tr> 
 <td> USERPROFILE </td> 
 <td> 用户目录 </td> 
 </tr> 
 <tr> 
 <td> USERDNSDOMAIN </td> 
 <td> 用户域 </td> 
 </tr> 
 <tr> 
 <td> PATHEXT </td> 
 <td> 可执行后缀 </td> 
 </tr> 
 <tr> 
 <td> JAVA_HOME </td> 
 <td> Java安装目录 </td> 
 </tr> 
 <tr> 
 <td> TEMP </td> 
 <td> 用户临时文件目录 </td> 
 </tr> 
 <tr> 
 <td> SystemDrive </td> 
 <td> 系统盘符 </td> 
 </tr> 
 <tr> 
 <td> ProgramFiles </td> 
 <td> 默认程序目录 </td> 
 </tr> 
 <tr> 
 <td> USERDOMAIN </td> 
 <td> 帐户的域的名称 </td> 
 </tr> 
 <tr> 
 <td> ALLUSERSPROFILE </td> 
 <td> 用户公共目录 </td> 
 </tr> 
 <tr> 
 <td> SESSIONNAME </td> 
 <td> Session名称 </td> 
 </tr> 
 <tr> 
 <td> TMP </td> 
 <td> 临时目录 </td> 
 </tr> 
 <tr> 
 <td> Path </td> 
 <td> path环境变量 </td> 
 </tr> 
 <tr> 
 <td> CLASSPATH </td> 
 <td> classpath环境变量 </td> 
 </tr> 
 <tr> 
 <td> PROCESSOR_ARCHITECTURE </td> 
 <td> 处理器体系结构 </td> 
 </tr> 
 <tr> 
 <td> OS </td> 
 <td> 操作系统类型 </td> 
 </tr> 
 <tr> 
 <td> PROCESSOR_LEVEL </td> 
 <td> 处理级别 </td> 
 </tr> 
 <tr> 
 <td> COMPUTERNAME </td> 
 <td> 计算机名 </td> 
 </tr> 
 <tr> 
 <td> Windir </td> 
 <td> 系统安装目录 </td> 
 </tr> 
 <tr> 
 <td> SystemRoot </td> 
 <td> 系统启动目录 </td> 
 </tr> 
 <tr> 
 <td> USERNAME </td> 
 <td> 用户名 </td> 
 </tr> 
 <tr> 
 <td> ComSpec </td> 
 <td> 命令行解释器可执行程序的准确路径 </td> 
 </tr> 
 <tr> 
 <td> APPDATA </td> 
 <td> 应用程序数据目录 </td> 
 </tr> 
 </tbody> 
</table>

# 其他网址 #

[Java System.getProperty 和 System.getenv 区别\_neweastsun的专栏-CSDN博客][Java System.getProperty _ System.getenv _neweastsun_-CSDN]

[java 的 System.getenv() 和 System.getProperty()\_jijianshuai的专栏-CSDN博客][java _ System.getenv_ _ System.getProperty_jijianshuai_-CSDN]

[Java--_--System.getProperty_System.getenv_IT_-CSDN]: https://knife.blog.csdn.net/article/details/118807155
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[Java System.getProperty _ System.getenv _neweastsun_-CSDN]: https://blog.csdn.net/neweastsun/article/details/81590821
[java _ System.getenv_ _ System.getProperty_jijianshuai_-CSDN]: https://blog.csdn.net/jijianshuai/article/details/78863032