Java之getProperty中都有什么key?

最近在做一个小工具，之前的工具虽然能检测网址是否合法，能判断能否连接。但是还不足够，后面会另外写一篇关于工具改进的文章，能输出下载资源的名称，因为url本身会跳转到对应的下载资源，我需要核对这些东西下载是否正确。

工具本身写得巧妙，将地址复制进txt文件。我自己在看源码之前在想着实现思路。

bat控制编译，数据从txt读取，唯一让我想不明白的是为什么无论我放到哪里，他都能读取到txt文件的位置，这是我想不到的地方，但是看了源码之后就恍然大悟了。其实使用了System.getProperty("user.dir")获取了相对路径，出于兴趣，我又找到了jdk里面的说明，同时最近重新看了properties的操作，对于遍历基本就是信手拈来。

public class TestProperties {public static void main(String[] args) {Properties p = System.getProperties();Enumeration keys = p.keys();while(keys.hasMoreElements()){String s = (String) keys.nextElement();System.out.println("key: "+s);System.out.println("value: "+p.getProperty(s));}}}看一下输出：key: java.runtime.namevalue: Java(TM) SE Runtime Environmentkey: sun.boot.library.pathvalue: C:\Program Files\Java\jdk1.7.0_67\jre\binkey: java.vm.versionvalue: 24.65-b04key: java.vm.vendorvalue: Oracle Corporationkey: java.vendor.urlvalue: key: path.separatorvalue: ;key: java.vm.namevalue: Java HotSpot(TM) 64-Bit Server VMkey: file.encoding.pkgvalue: sun.iokey: user.countryvalue: CNkey: user.scriptvalue: key: sun.java.launchervalue: SUN_STANDARDkey: sun.os.patch.levelvalue: Service Pack 1key: java.vm.specification.namevalue: Java Virtual Machine Specificationkey: user.dirvalue: E:\workspace\TestNetkey: java.runtime.versionvalue: 1.7.0_67-b01key: java.awt.graphicsenvvalue: sun.awt.Win32GraphicsEnvironmentkey: java.endorsed.dirsvalue: C:\Program Files\Java\jdk1.7.0_67\jre\lib\endorsedkey: os.archvalue: amd64key: java.io.tmpdirvalue: C:\Users\ADMINI~1\AppData\Local\Temp\key: line.separatorvalue: key: java.vm.specification.vendorvalue: Oracle Corporationkey: user.variantvalue: key: os.namevalue: Windows 7key: sun.jnu.encodingvalue: GBKkey: java.library.pathvalue: C:\Program Files\Java\jdk1.7.0_67\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;D:\tomcat7\lib;D:\tomcat7\bin;D:\ant1.8.2\bin;C:\Program Files\Java\jdk1.7.0_67\bin;C:\Program Files\TortoiseSVN\bin;D:\jar\apache-maven-3.2.3-bin\bin;D:\Program Files\AppServ\Apache2.2\bin;D:\Program Files\AppServ\php6;D:\Program Files\AppServ\MySQL\bin;.key: java.specification.namevalue: Java Platform API Specificationkey: java.class.versionvalue: 51.0key: sun.management.compilervalue: HotSpot 64-Bit Tiered Compilerskey: os.versionvalue: 6.1key: user.homevalue: C:\Users\Administratorkey: user.timezonevalue: key: java.awt.printerjobvalue: sun.awt.windows.WPrinterJobkey: file.encodingvalue: UTF-8key: java.specification.versionvalue: 1.7key: java.class.pathvalue: E:\workspace\TestNet\binkey: user.namevalue: Administratorkey: java.vm.specification.versionvalue: 1.7key: sun.java.commandvalue: TestPropertieskey: java.homevalue: C:\Program Files\Java\jdk1.7.0_67\jrekey: sun.arch.data.modelvalue: 64key: user.languagevalue: zhkey: java.specification.vendorvalue: Oracle Corporationkey: awt.toolkitvalue: sun.awt.windows.WToolkitkey: java.vm.infovalue: mixed modekey: java.versionvalue: 1.7.0_67key: java.ext.dirsvalue: C:\Program Files\Java\jdk1.7.0_67\jre\lib\ext;C:\Windows\Sun\Java\lib\extkey: sun.boot.class.pathvalue: C:\Program Files\Java\jdk1.7.0_67\jre\lib\resources.jar;C:\Program Files\Java\jdk1.7.0_67\jre\lib\rt.jar;C:\Program Files\Java\jdk1.7.0_67\jre\lib\sunrsasign.jar;C:\Program Files\Java\jdk1.7.0_67\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.7.0_67\jre\lib\jce.jar;C:\Program Files\Java\jdk1.7.0_67\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.7.0_67\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.7.0_67\jre\classeskey: java.vendorvalue: Oracle Corporationkey: file.separatorvalue: \key: java.vendor.url.bugvalue: key: sun.io.unicode.encodingvalue: UnicodeLittlekey: sun.cpu.endianvalue: littlekey: sun.desktopvalue: windowskey: sun.cpu.isalistvalue: amd64

各个key的说明

Key Description of Associated Value java.version Java Runtime Environment version java.vendor Java Runtime Environment vendor java.vendor.url Java vendor URL java.home Java installation directory java.vm.specification.version Java Virtual Machine specification version java.vm.specification.vendor Java Virtual Machine specification vendor java.vm.specification.name Java Virtual Machine specification name java.vm.version Java Virtual Machine implementation version java.vm.vendor Java Virtual Machine implementation vendor java.vm.name Java Virtual Machine implementation name java.specification.version Java Runtime Environment specification version java.specification.vendor Java Runtime Environment specification vendor java.specification.name Java Runtime Environment specification name java.class.version Java class format version number java.class.path Java class path java.library.path List of paths to search when loading libraries java.io.tmpdir Default temp file path java.compiler Name of JIT compiler to use java.ext.dirs Path of extension directory or directories os.name Operating system name os.arch Operating system architecture os.version Operating system version file.separator File separator ("/" on UNIX) path.separator Path separator (":" on UNIX) line.separator Line separator ("\n" on UNIX) user.name User's account name user.home User's home directory user.dir User's current working directory

然后让我想起了很久以前阿包给的一个方法，sun.arch.data.model其实查看的是操作系统的架构，，就是你windows或者其他OS是几位的。

而System.getProperty("user.dir")获取当前工作路径的方法也很是实用。

其实你已经错过了旅行的意义。