java項目中想擷取目前項目的路徑

問題由來：java項目中想擷取目前項目的路徑，發現Class.getClassLoader().getResource("")什麼的，

                   擷取的都是程式内的路徑，想擷取項目外的路徑，要用new File()這種方式擷取外部檔案。

解決方案：

首先貼兩個文章：

java擷取目前路徑 

System.getProperties()

其中，System.getProperties()方法，可以擷取目前的使用者資訊、電腦組態、java版本、項目路徑等資訊。

0 = {[email protected]} "java.runtime.name" -> "Java(TM) SE Runtime Environment"

1 = {[email protected]} "sun.boot.library.path" -> "E:\work\java\java8\jdk\jre\bin"

2 = {[email protected]} "java.vm.version" -> "25.101-b13"

3 = {[email protected]} "java.vm.vendor" -> "Oracle Corporation"

4 = {Hashta[email protected]} "java.vendor.url" -> "http://java.oracle.com/"

5 = {[email protected]} "path.separator" -> ";"

6 = {Hashtable$Ent[email protected]} "java.vm.name" -> "Java HotSpot(TM) 64-Bit Server VM"

7 = {[email protected]} "file.encoding.pkg" -> "sun.io"

8 = {[email protected]} "user.country" -> "CN"

9 = {[email protected]} "user.script" -> 

10 = {[email protected]} "sun.java.launcher" -> "SUN_STANDARD"

11 = {[email protected]} "sun.os.patch.level" -> 

12 = {[email protected]} "java.vm.specification.name" -> "Java Virtual Machine Specification"

13 = {Hashtable$Entry@477} "user.dir" -> "E:\work\git\project\gitClone\Interfaces"

14 = {H[email protected]} "java.runtime.version" -> "1.8.0_101-b13"

15 = {[email protected]} "java.awt.graphicsenv" -> "sun.awt.Win32GraphicsEnvironment"

16 = {[email protected]} "java.endorsed.dirs" -> "E:\work\java\java8\jdk\jre\lib\endorsed"

17 = {[email protected]} "os.arch" -> "amd64"

18 = {[email protected]} "java.io.tmpdir" -> "C:\Users\Andaren\AppData\Local\Temp\"

19 = {[email protected]} "line.separator" -> "\r\n"

20 = {Hashtable$Entr[email protected]} "java.vm.specification.vendor" -> "Oracle Corporation"

21 = {[email protected]} "user.variant" -> 

22 = {[email protected]} "os.name" -> "Windows 10"

23 = {[email protected]} "sun.jnu.encoding" -> "GBK"

24 = {[email protected]} "java.library.path" -> "E:\work\java\java8\jdk\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\ProgramData\Oracle\Java\javapath;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;E:\work\git\git\Git\cmd;E:\work\node\node\;E:\work\java\java8\jdk\bin;C:\Users\Andaren\AppData\Roaming\npm;%USERPROFILE%\AppData\Local\Microsoft\WindowsApps;;."

25 = {[email protected]} "java.specification.name" -> "Java Platform API Specification"

26 = {[email protected]} "java.class.version" -> "52.0"

27 = {[email protected]} "sun.management.compiler" -> "HotSpot 64-Bit Tiered Compilers"

28 = {[email protected]} "os.version" -> "10.0"

29 = {[email protected]} "user.home" -> "C:\Users\Andaren"

30 = {[email protected]} "user.timezone" -> 

31 = {Hashtable$Entr[email protected]} "java.awt.printerjob" -> "sun.awt.windows.WPrinterJob"

32 = {[email protected]} "file.encoding" -> "UTF-8"

33 = {[email protected]} "java.specification.version" -> "1.8"

34 = {[email protected]} "java.class.path" -> "E:\work\java\java8\jdk\jre\lib\charsets.jar;E:\work\java\java8\jdk\jre\lib\deploy.jar;E:\work\java\java8\jdk\jre\lib\ext\access-bridge-64.jar;E:\work\java\java8\jdk\jre\lib\ext\cldrdata.jar;E:\work\java\java8\jdk\jre\lib\ext\dnsns.jar;E:\work\java\java8\jdk\jre\lib\ext\jaccess.jar;E:\work\java\java8\jdk\jre\lib\ext\jfxrt.jar;E:\work\java\java8\jdk\jre\lib\ext\localedata.jar;E:\work\java\java8\jdk\jre\lib\ext\nashorn.jar;E:\work\java\java8\jdk\jre\lib\ext\sunec.jar;E:\work\java\java8\jdk\jre\lib\ext\sunjce_provider.jar;E:\work\java\java8\jdk\jre\lib\ext\sunmscapi.jar;E:\work\java\java8\jdk\jre\lib\ext\sunpkcs11.jar;E:\work\java\java8\jdk\jre\lib\ext\zipfs.jar;E:\work\java\java8\jdk\jre\lib\javaws.jar;E:\work\java\java8\jdk\jre\lib\jce.jar;E:\work\java\java8\jdk\jre\lib\jfr.jar;E:\work\java\java8\jdk\jre\lib\jfxswt.jar;E:\work\java\java8\jdk\jre\lib\jsse.jar;E:\work\java\java8\jdk\jre\lib\management-agent.jar;E:\work\java\java8\jdk\jre\lib\plugin.jar;E:\work\java\ja

35 = {[email protected]} "user.name" -> "Andaren"

36 = {[email protected]} "java.vm.specification.version" -> "1.8"

37 = {[email protected]} "sun.java.command" -> "TestCase"

38 = {Has[email protected]} "java.home" -> "E:\work\java\java8\jdk\jre"

39 = {[email protected]} "sun.arch.data.model" -> "64"

40 = {[email protected]} "user.language" -> "zh"

41 = {Hashtable$E[email protected]} "java.specification.vendor" -> "Oracle Corporation"

42 = {Has[email protected]} "awt.toolkit" -> "sun.awt.windows.WToolkit"

43 = {[email protected]} "java.vm.info" -> "mixed mode"

44 = {[email protected]} "java.version" -> "1.8.0_101"

45 = {[email protected]} "java.ext.dirs" -> "E:\work\java\java8\jdk\jre\lib\ext;C:\WINDOWS\Sun\Java\lib\ext"

46 = {[email protected]} "sun.boot.class.path" -> "E:\work\java\java8\jdk\jre\lib\resources.jar;E:\work\java\java8\jdk\jre\lib\rt.jar;E:\work\java\java8\jdk\jre\lib\sunrsasign.jar;E:\work\java\java8\jdk\jre\lib\jsse.jar;E:\work\java\java8\jdk\jre\lib\jce.jar;E:\work\java\java8\jdk\jre\lib\charsets.jar;E:\work\java\java8\jdk\jre\lib\jfr.jar;E:\work\java\java8\jdk\jre\classes"

47 = {[email protected]} "java.vendor" -> "Oracle Corporation"

48 = {[email protected]} "file.separator" -> "\"

49 = {[email protected]} "java.vendor.url.bug" -> "http://bugreport.sun.com/bugreport/"

50 = {Hash[email protected]} "sun.io.unicode.encoding" -> "UnicodeLittle"

51 = {[email protected]} "sun.cpu.endian" -> "little"

52 = {[email protected]} "sun.desktop" -> "windows"

53 = {[email protected]} "sun.cpu.isalist" -> "amd64"

很強大啊。