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+"%"; 
         } 
     }

------解决方案--------------------

Java code

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; 
    }