java监控linux服务器CPU,内存等信息

最近公司在做爬虫系统，我接到一个需求是获取服务器CPU,内存等信息。一开始我打算通过linux shell获取然后输出到文件，java读取文件获得。后来回想一切皆文件的linux应该本来就有记录在文件中，经过查找资料，找到了解决方法。

资料参考：http://www.jb51.net/article/75002.htm

* 取得linux系统下的cpu、内存信息
*
* */
public  final  class LinuxSystemTool
{
/**
* get memory by used info
*
* @return int[] result
* result.length==4;int[0]=MemTotal;int[1]=MemFree;int[2]=SwapTotal;int[3]=SwapFree;
* @throws IOException
* @throws InterruptedException
*/
public  static  int [] getMemInfo() throws IOException, InterruptedException
{
File file = new File( "/proc/meminfo" );
BufferedReader br = new BufferedReader( new InputStreamReader(
new FileInputStream(file)));
int [] result = new  int [ 4 ];
String str = null ;
StringTokenizer token = null ;
while ((str = br.readLine()) != null )
{
token = new StringTokenizer(str);
if (!token.hasMoreTokens())
continue ;

str = token.nextToken();
if (!token.hasMoreTokens())
continue ;

if (str.equalsIgnoreCase( "MemTotal:" ))
result[0 ] = Integer.parseInt(token.nextToken());
else  if (str.equalsIgnoreCase( "MemFree:" ))
result[1 ] = Integer.parseInt(token.nextToken());
else  if (str.equalsIgnoreCase( "SwapTotal:" ))
result[2 ] = Integer.parseInt(token.nextToken());
else  if (str.equalsIgnoreCase( "SwapFree:" ))
result[3 ] = Integer.parseInt(token.nextToken());
}

return result;
}

/**
* get memory by used info
*
* @return float efficiency
* @throws IOException
* @throws InterruptedException
*/
public  static  float getCpuInfo() throws IOException, InterruptedException
{
File file = new File( "/proc/stat" );
BufferedReader br = new BufferedReader( new InputStreamReader(
new FileInputStream(file)));
StringTokenizer token = new StringTokenizer(br.readLine());
token.nextToken();
int user1 = Integer.parseInt(token.nextToken());
int nice1 = Integer.parseInt(token.nextToken());
int sys1 = Integer.parseInt(token.nextToken());
int idle1 = Integer.parseInt(token.nextToken());

Thread.sleep(1000 );

br = new BufferedReader(
new InputStreamReader( new FileInputStream(file)));
token = new StringTokenizer(br.readLine());
token.nextToken();
int user2 = Integer.parseInt(token.nextToken());
int nice2 = Integer.parseInt(token.nextToken());
int sys2 = Integer.parseInt(token.nextToken());
int idle2 = Integer.parseInt(token.nextToken());

return ( float )((user2 + sys2 + nice2) - (user1 + sys1 + nice1)) / ( float )((user2 + nice2 + sys2 + idle2) - (user1 + nice1 + sys1 + idle1));
}
}

同理：要获取LINUX的CPU温度（如果文件存在）：

InputStreamReader(new FileInputStream（new File("/proc/acpi/thermal_zone/THM/temperature")）