java 获取服务器CPU、内存、硬盘使用量

 

/**
 * <获取系统信息类>
 * <获取系统信息，如CPU、内存、硬盘使用情况>
 * @author  wenkaixuan
 * @version  [版本号, 2012-5-9]
 * @see  [相关类/方法]
 * @since  [产品/模块版本]
 */
public class GetSystemInfo
{
    private static final int CPUTIME = 500;
    
    private static final int PERCENT = 100;
    
    private static final int FAULTLENGTH = 10;
    
    //获取内存使用率
    public static String getMemery()
    {
        OperatingSystemMXBean osmxb = (OperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean();
        // 总的物理内存+虚拟内存
        long totalvirtualMemory = osmxb.getTotalSwapSpaceSize();
        // 剩余的物理内存
        long freePhysicalMemorySize = osmxb.getFreePhysicalMemorySize();
        Double compare = (Double)(1 - freePhysicalMemorySize * 1.0 / totalvirtualMemory) * 100;
        String str = "内存已使用:" + compare.intValue() + "%";
        return str;
    }
    
    //获取文件系统使用率
    public static List<String> getDisk()
    {
        // 操作系统
        List<String> list = new ArrayList<String>();
        for (char c = 'A'; c <= 'Z'; c++)
        {
            String dirName = c + ":/";
            File win = new File(dirName);
            if (win.exists())
            {
                long total = (long)win.getTotalSpace();
                long free = (long)win.getFreeSpace();
                Double compare = (Double)(1 - free * 1.0 / total) * 100;
                String str = c + ":盘  已使用 " + compare.intValue() + "%";
                list.add(str);
            }
        }
        return list;
    }
    
    //获得cpu使用率
    public static String getCpuRatioForWindows()
    {
        try
        {
            String procCmd =
                System.getenv("windir")
                    + "\\system32\\wbem\\wmic.exe process get Caption,CommandLine,KernelModeTime,ReadOperationCount,ThreadCount,UserModeTime,WriteOperationCount";
            // 取进程信息
            long[] c0 = readCpu(Runtime.getRuntime().exec(procCmd));
            Thread.sleep(CPUTIME);
            long[] c1 = readCpu(Runtime.getRuntime().exec(procCmd));
            if (c0 != null && c1 != null)
            {
                long idletime = c1[0] - c0[0];
                long busytime = c1[1] - c0[1];
                return "CPU使用率:" + Double.valueOf(PERCENT * (busytime) * 1.0 / (busytime + idletime)).intValue() + "%";
            }
            else
            {
                return "CPU使用率:" + 0 + "%";
            }
        }
        catch (Exception ex)
        {
            ex.printStackTrace();
            return "CPU使用率:" + 0 + "%";
        }
    }
    
    //读取cpu相关信息
    private static long[] readCpu(final Process proc)
    {
        long[] retn = new long[2];
        try
        {
            proc.getOutputStream().close();
            InputStreamReader ir = new InputStreamReader(proc.getInputStream());
            LineNumberReader input = new LineNumberReader(ir);
            String line = input.readLine();
            if (line == null || line.length() < FAULTLENGTH)
            {
                return null;
            }
            int capidx = line.indexOf("Caption");
            int cmdidx = line.indexOf("CommandLine");
            int rocidx = line.indexOf("ReadOperationCount");
            int umtidx = line.indexOf("UserModeTime");
            int kmtidx = line.indexOf("KernelModeTime");
            int wocidx = line.indexOf("WriteOperationCount");
            long idletime = 0;
            long kneltime = 0;
            long usertime = 0;
            while ((line = input.readLine()) != null)
            {
                if (line.length() < wocidx)
                {
                    continue;
                }
                // 字段出现顺序：Caption,CommandLine,KernelModeTime,ReadOperationCount,
                // ThreadCount,UserModeTime,WriteOperation
                String caption = substring(line, capidx, cmdidx - 1).trim();
                String cmd = substring(line, cmdidx, kmtidx - 1).trim();
                if (cmd.indexOf("wmic.exe") >= 0)
                {
                    continue;
                }
                String s1 = substring(line, kmtidx, rocidx - 1).trim();
                String s2 = substring(line, umtidx, wocidx - 1).trim();
                if (caption.equals("System Idle Process") || caption.equals("System"))
                {
                    if (s1.length() > 0)
                        idletime += Long.valueOf(s1).longValue();
                    if (s2.length() > 0)
                        idletime += Long.valueOf(s2).longValue();
                    continue;
                }
                if (s1.length() > 0)
                    kneltime += Long.valueOf(s1).longValue();
                if (s2.length() > 0)
                    usertime += Long.valueOf(s2).longValue();
            }
            retn[0] = idletime;
            retn[1] = kneltime + usertime;
            return retn;
        }
        catch (Exception ex)
        {
            ex.printStackTrace();
        }
        finally
        {
            try
            {
                proc.getInputStream().close();
            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
        }
        return null;
    }
    
    /**
    * 由于String.subString对汉字处理存在问题（把一个汉字视为一个字节)，因此在 包含汉字的字符串时存在隐患，现调整如下：
    * @param src 要截取的字符串
    * @param start_idx 开始坐标（包括该坐标)
    * @param end_idx 截止坐标（包括该坐标）
    * @return
    */
    private static String substring(String src, int start_idx, int end_idx)
    {
        byte[] b = src.getBytes();
        String tgt = "";
        for (int i = start_idx; i <= end_idx; i++)
        {
            tgt += (char)b[i];
        }
        return tgt;
    }