java获得CPU、系统内存情况

JXM：Monitoring and Management Interface for the Java™ Platform

通过jmx可以监控vm内存使用,系统内存使用等

以下是网上某博客代码，特点是通过window和linux命令获得CPU使用率。


Java代码

       利用java程序实现获取计算机cpu利用率和内存使用信息。   
     
        创建一个Bean用来存贮要得到的信   
     
    public class MonitorInfoBean {   
        /** 可使用内存. */   
        private long totalMemory;   
         
        /**  剩余内存. */   
        private long freeMemory;   
         
        /** 最大可使用内存. */   
        private long maxMemory;   
         
        /** 操作系统. */   
        private String osName;   
         
        /** 总的物理内存. */   
        private long totalMemorySize;   
         
        /** 剩余的物理内存. */   
        private long freePhysicalMemorySize;   
         
        /** 已使用的物理内存. */   
        private long usedMemory;   
         
        /** 线程总数. */   
        private int totalThread;   
         
        /** cpu使用率. */   
        private double cpuRatio;   
     
        public long getFreeMemory() {   
            return freeMemory;   
        }   
     
        public void setFreeMemory(long freeMemory) {   
            this.freeMemory = freeMemory;   
        }   
     
        public long getFreePhysicalMemorySize() {   
            return freePhysicalMemorySize;   
        }   
     
        public void setFreePhysicalMemorySize(long freePhysicalMemorySize) {   
            this.freePhysicalMemorySize = freePhysicalMemorySize;   
        }   
     
        public long getMaxMemory() {   
            return maxMemory;   
        }   
     
        public void setMaxMemory(long maxMemory) {   
            this.maxMemory = maxMemory;   
        }   
     
        public String getOsName() {   
            return osName;   
        }   
     
        public void setOsName(String osName) {   
            this.osName = osName;   
        }   
     
        public long getTotalMemory() {   
            return totalMemory;   
        }   
     
        public void setTotalMemory(long totalMemory) {   
            this.totalMemory = totalMemory;   
        }   
     
        public long getTotalMemorySize() {   
            return totalMemorySize;   
        }   
     
        public void setTotalMemorySize(long totalMemorySize) {   
            this.totalMemorySize = totalMemorySize;   
        }   
     
        public int getTotalThread() {   
            return totalThread;   
        }   
     
        public void setTotalThread(int totalThread) {   
            this.totalThread = totalThread;   
        }   
     
        public long getUsedMemory() {   
            return usedMemory;   
        }   
     
        public void setUsedMemory(long usedMemory) {   
            this.usedMemory = usedMemory;   
        }   
     
        public double getCpuRatio() {   
            return cpuRatio;   
        }   
     
        public void setCpuRatio(double cpuRatio) {   
            this.cpuRatio = cpuRatio;   
        }   
    }   
     
        之后，建立bean的接口   
     
    public interface IMonitorService {   
        public MonitorInfoBean getMonitorInfoBean() throws Exception;   
     
    }   
     
      然后，就是最关键的，得到cpu的利用率，已用内存，可用内存，最大内存等信息。   
     
    import java.io.InputStreamReader;   
    import java.io.LineNumberReader;   
     
    import sun.management.ManagementFactory;   
     
    import com.sun.management.OperatingSystemMXBean;   
    import java.io.*;   
    import java.util.StringTokenizer;   
     
    /**  
    
    * 获取系统信息的业务逻辑实现类.  
    * @author GuoHuang  
    */   
    public class MonitorServiceImpl implements IMonitorService {   
         
        private static final int CPUTIME = 30;   
     
        private static final int PERCENT = 100;   
     
        private static final int FAULTLENGTH = 10;   
         
        private static final File versionFile = new File("/proc/version");   
        private static String linuxVersion = null;   
     
        /**  
         * 获得当前的监控对象.  
         * @return 返回构造好的监控对象  
         * @throws Exception  
         * @author GuoHuang  
         */   
        public MonitorInfoBean getMonitorInfoBean() throws Exception {   
            int kb = 1024;   
             
            // 可使用内存   
            long totalMemory = Runtime.getRuntime().totalMemory() / kb;   
            // 剩余内存   
            long freeMemory = Runtime.getRuntime().freeMemory() / kb;   
            // 最大可使用内存   
            long maxMemory = Runtime.getRuntime().maxMemory() / kb;   
     
            OperatingSystemMXBean osmxb = (OperatingSystemMXBean) ManagementFactory   
                    .getOperatingSystemMXBean();   
     
            // 操作系统   
            String osName = System.getProperty("os.name");   
            // 总的物理内存   
            long totalMemorySize = osmxb.getTotalPhysicalMemorySize() / kb;   
            // 剩余的物理内存   
            long freePhysicalMemorySize = osmxb.getFreePhysicalMemorySize() / kb;   
            // 已使用的物理内存   
            long usedMemory = (osmxb.getTotalPhysicalMemorySize() - osmxb   
                    .getFreePhysicalMemorySize())   
                    / kb;   
     
            // 获得线程总数   
            ThreadGroup parentThread;   
            for (parentThread = Thread.currentThread().getThreadGroup(); parentThread   
                    .getParent() != null; parentThread = parentThread.getParent())   
                ;   
            int totalThread = parentThread.activeCount();   
     
            double cpuRatio = 0;   
            if (osName.toLowerCase().startsWith("windows")) {   
                cpuRatio = this.getCpuRatioForWindows();   
            }   
            else {   
             cpuRatio = this.getCpuRateForLinux();   
            }   
             
            // 构造返回对象   
            MonitorInfoBean infoBean = new MonitorInfoBean();   
            infoBean.setFreeMemory(freeMemory);   
            infoBean.setFreePhysicalMemorySize(freePhysicalMemorySize);   
            infoBean.setMaxMemory(maxMemory);   
            infoBean.setOsName(osName);   
            infoBean.setTotalMemory(totalMemory);   
            infoBean.setTotalMemorySize(totalMemorySize);   
            infoBean.setTotalThread(totalThread);   
            infoBean.setUsedMemory(usedMemory);   
            infoBean.setCpuRatio(cpuRatio);   
            return infoBean;   
        }   
        private static double getCpuRateForLinux(){   
            InputStream is = null;   
            InputStreamReader isr = null;   
            BufferedReader brStat = null;   
            StringTokenizer tokenStat = null;   
            try{   
                System.out.println("Get usage rate of CUP , linux version: "+linuxVersion);   
     
                Process process = Runtime.getRuntime().exec("top -b -n 1");   
                is = process.getInputStream();                     
                isr = new InputStreamReader(is);   
                brStat = new BufferedReader(isr);   
                 
                if(linuxVersion.equals("2.4")){   
                    brStat.readLine();   
                    brStat.readLine();   
                    brStat.readLine();   
                    brStat.readLine();   
                     
                    tokenStat = new StringTokenizer(brStat.readLine());   
                    tokenStat.nextToken();   
                    tokenStat.nextToken();   
                    String user = tokenStat.nextToken();   
                    tokenStat.nextToken();   
                    String system = tokenStat.nextToken();   
                    tokenStat.nextToken();   
                    String nice = tokenStat.nextToken();   
                     
                    System.out.println(user+" , "+system+" , "+nice);   
                     
                    user = user.substring(0,user.indexOf("%"));   
                    system = system.substring(0,system.indexOf("%"));   
                    nice = nice.substring(0,nice.indexOf("%"));   
                     
                    float userUsage = new Float(user).floatValue();   
                    float systemUsage = new Float(system).floatValue();   
                    float niceUsage = new Float(nice).floatValue();   
                     
                    return (userUsage+systemUsage+niceUsage)/100;   
                }else{   
                    brStat.readLine();   
                    brStat.readLine();   
                         
                    tokenStat = new StringTokenizer(brStat.readLine());   
                    tokenStat.nextToken();   
                    tokenStat.nextToken();   
                    tokenStat.nextToken();   
                    tokenStat.nextToken();   
                    tokenStat.nextToken();   
                    tokenStat.nextToken();   
                    tokenStat.nextToken();   
                    String cpuUsage = tokenStat.nextToken();   
                         
                     
                    System.out.println("CPU idle : "+cpuUsage);   
                    Float usage = new Float(cpuUsage.substring(0,cpuUsage.indexOf("%")));   
                     
                    return (1-usage.floatValue()/100);   
                }   
     
                  
            } catch(IOException ioe){   
                System.out.println(ioe.getMessage());   
                freeResource(is, isr, brStat);   
                return 1;   
            } finally{   
                freeResource(is, isr, brStat);   
            }   
     
        }   
        private static void freeResource(InputStream is, InputStreamReader isr, BufferedReader br){   
            try{   
                if(is!=null)   
                    is.close();   
                if(isr!=null)   
                    isr.close();   
                if(br!=null)   
                    br.close();   
            }catch(IOException ioe){   
                System.out.println(ioe.getMessage());   
            }   
        }   
     
     
        /**  
         * 获得CPU使用率.  
         * @return 返回cpu使用率  
         * @author GuoHuang  
         */   
        private double 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 Double.valueOf(   
                            PERCENT * (busytime) / (busytime + idletime))   
                            .doubleValue();   
                } else {   
                    return 0.0;   
                }   
            } catch (Exception ex) {   
                ex.printStackTrace();   
                return 0.0;   
            }   
        }   
     
        /**       
    
    * 读取CPU信息.  
         * @param proc  
         * @return  
         * @author GuoHuang  
         */   
        private 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 = Bytes.substring(line, capidx, cmdidx - 1)   
                            .trim();   
                    String cmd = Bytes.substring(line, cmdidx, kmtidx - 1).trim();   
                    if (cmd.indexOf("wmic.exe") >= 0) {   
                        continue;   
                    }   
                    // log.info("line="+line);   
                    if (caption.equals("System Idle Process")   
                            || caption.equals("System")) {   
                        idletime += Long.valueOf(   
                                Bytes.substring(line, kmtidx, rocidx - 1).trim())   
                                .longValue();   
                        idletime += Long.valueOf(   
                                Bytes.substring(line, umtidx, wocidx - 1).trim())   
                                .longValue();   
                        continue;   
                    }   
     
                    kneltime += Long.valueOf(   
                            Bytes.substring(line, kmtidx, rocidx - 1).trim())   
                            .longValue();   
                    usertime += Long.valueOf(   
                            Bytes.substring(line, umtidx, wocidx - 1).trim())   
                            .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;   
        }   
         
        /**     测试方法.  
         * @param args  
         * @throws Exception  
         * @author GuoHuang  
           */   
        public static void main(String[] args) throws Exception {   
            IMonitorService service = new MonitorServiceImpl();   
            MonitorInfoBean monitorInfo = service.getMonitorInfoBean();   
            System.out.println("cpu占有率=" + monitorInfo.getCpuRatio());   
             
            System.out.println("可使用内存=" + monitorInfo.getTotalMemory());   
            System.out.println("剩余内存=" + monitorInfo.getFreeMemory());   
            System.out.println("最大可使用内存=" + monitorInfo.getMaxMemory());   
             
            System.out.println("操作系统=" + monitorInfo.getOsName());   
            System.out.println("总的物理内存=" + monitorInfo.getTotalMemorySize() + "kb");   
            System.out.println("剩余的物理内存=" + monitorInfo.getFreeMemory() + "kb");   
            System.out.println("已使用的物理内存=" + monitorInfo.getUsedMemory() + "kb");   
            System.out.println("线程总数=" + monitorInfo.getTotalThread() + "kb");   
        }   
    }   
     
        其中，Bytes类用来处理字符串   
     
       public class Bytes {   
        public 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;   
        }   
    }