因為論壇有人問到這個問題,所以就寫了這篇文章.希望對大家有所幫助.
一般來講,要用java得到硬盤空間,有3種方法:
 1 .?調用system的command,然后分析得到的結果,這種方法有很強的系統依賴性,linux下和win下要分別寫程序
下面是一個win下的例子,編譯成功之后,運行java?Diskspace?yourdir(比如c:\)
 import ?java.io.BufferedReader;
 import ?java.io.InputStreamReader;

 /**
*?Determine?free?disk?space?for?a?given?directory?by?
*?parsing?the?output?of?the?dir?command.
*?This?class?is?inspired?by?the?code?at
*?Works?only?under?Windows?under?certain?circumstances.
*?Yes,?it's?that?shaky.
*?Requires?Java?1.4?or?higher.
*?@[EMAIL?PROTECTED]?
*Marco?Schmidt
 */
public ? class ?Diskspace
 {
 private ?Diskspace()
 {
 // ?prevent?instantiation?of?this?class
}

/**
*?Return?available?free?disk?space?for?a?directory.
*?@[EMAIL?PROTECTED]
dirName?name?of?the?directory
*?@[EMAIL?PROTECTED]
free?disk?space?in?bytes?or?-1?if?unknown
 */
public ? static ? long ?getFreeDiskSpace(String?dirName)
 {
 try
{
 // ?guess?correct?'dir'?command?by?looking?at?the?
 // ?operating?system?name
String?os? = ?System.getProperty( " os.name " );
String?command;
 if ?(os.equals( " Windows?NT " )? ||
os.equals( " Windows?2000 " ))
 {
command? = ? " cmd.exe?/c?dir? " ? + ?dirName;
}
else
{
command? = ? " command.com?/c?dir? " ? + ?dirName;
}
// ?run?the?dir?command?on?the?argument?directory?name
Runtime?runtime? = ?Runtime.getRuntime();
Process?process? = ? null ;
process? = ?runtime.exec(command);
 if ?(process? == ? null )
 {
 return ? - 1 ;
}
// ?read?the?output?of?the?dir?command
 // ?only?the?last?line?is?of?interest?
BufferedReader?in? = ? new ?BufferedReader(
 new ?InputStreamReader(process.getInputStream()));
String?line;
String?freeSpace? = ? null ;
 while ?((line? = ?in.readLine())? != ? null )
 {
freeSpace? = ?line;
}
if ?(freeSpace? == ? null )
 {
 return ? - 1 ;
}
process.destroy();
 // ?remove?dots?&?commas?&?leading?and?trailing?whitespace
freeSpace? = ?freeSpace.trim();
freeSpace? = ?freeSpace.replaceAll( " \\. " ,? "" );
freeSpace? = ?freeSpace.replaceAll( " , " ,? "" );
String[]?items? = ?freeSpace.split( " ? " );
 // ?the?first?valid?numeric?value?in?items?after(!)?index?0
 // ?is?probably?the?free?disk?space
int ?index? = ? 1 ;
 while ?(index? < ?items.length)
 {
 try
{
 long ?bytes? = ?Long.parseLong(items[index ++ ]);
 return ?bytes;
}
catch ?(NumberFormatException?nfe)
 {
}
}
return ? - 1 ;
}
catch ?(Exception?exception)
 {
 return ? - 1 ;
} ?
}

/**
*?Command?line?program?to?print?the?free?diskspace?to?stdout
*?for?all?26?potential?root?directories?A:\?to?Z:\
*?(when?no?parameters?are?given?to?this?program)
*?or?for?those?directories?(drives)?specified?as?parameters.
*?@[EMAIL?PROTECTED]
args?program?parameters
 */
public ? static ? void ?main(String[]?args)
 {
 if ?(args.length? == ? 0 )
 {
 for ?( char ?c? = ? ' A ' ;?c? <= ? ' Z ' ;?c ++ )
 {
String?dirName? = ?c? + ? " :\\ " ;
System.out.println(dirName? + ? " ? " ? +
getFreeDiskSpace(dirName));
}
}
else
{
 for ?( int ?i? = ? 0 ;?i? < ?args.length;?i ++ )
 {
System.out.println(args[i]? + ? " ? " ? +
getFreeDiskSpace(args[i]));
}
}
}
}

方法二:使用Jconfig,可以跨平臺
從http: // www.tolstoy.com/samizdat/jconfig.html上下載jconfig.
下載的包的sample里有很簡單的例子,如果是要得到磁盤空間的話:
用FileRegistry.getVolumes()得到DiskVolume
然后call?getFreeSpace()和getMaxCapacity()
就是這么簡單..:)

方法三:jni
這個是解決所有和os相關的操作的萬能利器了.
例子我也懶得寫了.
寫一個dll然后call之即可.