java 获得计算机的cpu使用率，物理内存等信息

public interface IMonitorService {
public MonitorInfoBean getMonitorInfoBean() throws Exception;
}
实现类
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;
import java.util.StringTokenizer;
//import sun.management.*;
//import com.sun.management.*;
import sun.management.ManagementFactory;
import com.sun.management.OperatingSystemMXBean;
/*采集系统采集数据实现类*/
/**
* @author Administrator
*
*/
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 String osVersion = null;
private String mIpAddress = null;
private String dDateTime = null;
private float totalMemorySize = 0.0f;
private float buffersMemory = 0.0f;
private float cachedMemory = 0.0f;
private float usedMemory = 0.0f;
private float memoryRatio;
/**
  * 获得当前的监控对象.
  *
  * @return 返回构造好的监控对象
  * @throws Exception
*/
public MonitorInfoBean getMonitorInfoBean() throws Exception {
  int kb = 1024;
  CountDate ddate = new CountDate();
  osVersion = System.getProperty("os.version");
  OperatingSystemMXBean osmxb = (OperatingSystemMXBean) ManagementFactory
    .getOperatingSystemMXBean();
  // 操作系统
  String osName = System.getProperty("os.name");
  // 主机IP
  if (osName.toLowerCase().startsWith("windows")) {
   mIpAddress = this.getWindowsIp();
  } else {
   mIpAddress = this.getLinuxIP();
  }
  if (osName.toLowerCase().startsWith("windows")) {
   // 总的物理内存
   float totalPhysicalMemorySize = osmxb.getTotalPhysicalMemorySize()
     / kb;
   float usedPhysicalMemorySize = (osmxb.getTotalPhysicalMemorySize() - osmxb
     .getFreePhysicalMemorySize())
     / kb;
   totalMemorySize = Float.parseFloat(String.format("%.1f",
     totalPhysicalMemorySize));
   // 已使用的物理内存
   usedMemory = Float.parseFloat(String.format("%.1f",
     usedPhysicalMemorySize));
   // windows内存使用率
   memoryRatio = Float.parseFloat(String.format("%.1f",
     (usedMemory / totalMemorySize) * 100));
  } else {
   float[] result = null;
   result = getLinuxMemInfo();
   totalMemorySize = Float
     .parseFloat(String.format("%.1f", result[0]));
   buffersMemory = Float.parseFloat(String.format("%.1f", result[1]));
   cachedMemory = Float.parseFloat(String.format("%.1f", result[2]));
   usedMemory = totalMemorySize - result[3];
   // linux内存使用率
   memoryRatio = Float
     .parseFloat(String
       .format(
         "%.1f",
         ((usedMemory - (cachedMemory + buffersMemory)) / totalMemorySize) * 100));
  }
  // 获得cpu频率
  double cpuRatio = 0;
  if (osName.toLowerCase().startsWith("windows")) {
   cpuRatio = this.getCpuRatioForWindows();
  } else {
   cpuRatio = this.getCpuRateForLinux();
  }
  /* 取得数据时间 */
  dDateTime = ddate.getCurrentYMDHMS();
  // 构造返回对象
  MonitorInfoBean infoBean = new MonitorInfoBean();
  infoBean.setOsName(osName);
  infoBean.setCpuRatio(cpuRatio);
  infoBean.setMIpAddress(mIpAddress);
  infoBean.setDDateTime(dDateTime);
  infoBean.setBuffersMemory(buffersMemory);
  infoBean.setCachedMemory(cachedMemory);
  infoBean.setUsedMemory(usedMemory);
  infoBean.setTotalMemorySize(totalMemorySize);
  infoBean.setMemoryRatio(memoryRatio);
  return infoBean;
}
/**
  * 获得Linux下IP地址.
  *
  * @return 返回Linux下IP地址
*/
public String getLinuxIP() {
  String ip = "";
  try {
   Enumeration<?> e1 = (Enumeration<?>) NetworkInterface
     .getNetworkInterfaces();
   while (e1.hasMoreElements()) {
    NetworkInterface ni = (NetworkInterface) e1.nextElement();
    if (!ni.getName().equals("eth0")) {
     continue;
    } else {
     Enumeration<?> e2 = ni.getInetAddresses();
     while (e2.hasMoreElements()) {
      InetAddress ia = (InetAddress) e2.nextElement();
      if (ia instanceof Inet6Address)
       continue;
      ip = ia.getHostAddress();
     }
     break;
    }
   }
  } catch (SocketException e) {
   e.printStackTrace();
   System.exit(-1);
  }
  return ip;
}
public String getWindowsIp() {
  String ip = "";
  try {
   ip = InetAddress.getLocalHost().getHostAddress();
  } catch (UnknownHostException e) {
   e.printStackTrace();
  }
  return ip;
}
/**
  * 获得Linux下CPU使用率.
  *
  * @return 返回Linux下cpu使用率
  */
private double getCpuRateForLinux() {
  InputStream is = null;
  InputStreamReader isr = null;
  BufferedReader brStat = null;
  StringTokenizer tokenStat = null;
  try {
   Process process = Runtime.getRuntime().exec("top -b -n 1");
   is = process.getInputStream();
   isr = new InputStreamReader(is);
   brStat = new BufferedReader(isr);
   if (osVersion.startsWith("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();
    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();
    String cpuUsage = tokenStat.nextToken();
    Float usage = new Float(cpuUsage.substring(0, cpuUsage
      .indexOf("%")));
    return ((1 - usage.floatValue() / 100) * 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windows下CPU使用率.
  *
  * @return 返回windows下cpu使用率
  */
private double getCpuRatioForWindows() {
  try {
   mIpAddress = InetAddress.getLocalHost().getHostAddress();
   String procCmd = System.getenv("windir")
     + " 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
  */
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 = line.substring(capidx, cmdidx - 1)
      .trim();
    String cmd = line.substring( 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(
       line.substring(kmtidx, rocidx - 1).trim())
       .longValue();
     idletime += Long.valueOf(
       line.substring(umtidx, wocidx - 1).trim())
       .longValue();
     continue;
    }
    kneltime += Long.valueOf(
      line.substring(kmtidx, rocidx - 1).trim())
      .longValue();
    usertime += Long.valueOf(
      line.substring(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;
}
public float[] getLinuxMemInfo() {
  File file = new File("/proc/meminfo");
  float result[] = new float[4];
  try {
   BufferedReader br = new BufferedReader(new InputStreamReader(
     new FileInputStream(file)));
   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] = Long.parseLong(token.nextToken());
    }
    if (str.equalsIgnoreCase("Buffers:")) {
     result[1] = Long.parseLong(token.nextToken());
    }
    if (str.equalsIgnoreCase("Cached:")) {
     result[2] = Long.parseLong(token.nextToken());
    }
    if (str.equalsIgnoreCase("MemFree:")) {
     result[3] = Long.parseLong(token.nextToken());
    }
   }
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }
  return result;
}
/**
  * 测试方法.
  *
  * @param args
  * @throws Exception
  */
public static void information() {
  MonitorInfoBean monitorInfo = null;
  IMonitorService service = new MonitorServiceImpl();
  try {
   monitorInfo = service.getMonitorInfoBean();
  } catch (Exception e) {
   e.printStackTrace();
  }
  String osName = monitorInfo.getOsName();
  String cpuRatio = String.valueOf(monitorInfo.getCpuRatio());
  String mIpAddress = monitorInfo.getMIpAddress();
  String memoryRatio = String.valueOf(monitorInfo.getMemoryRatio());
  String dDateTime = monitorInfo.getDDateTime();
  System.out.println("操作系统名字：" + osName);
  System.out.println("cpu使用频率:" + cpuRatio);
  System.out.println("内存使用率:" + memoryRatio);
  System.out.println("总的物理内存:" + monitorInfo.getTotalMemorySize());
  System.out.println("主机IP地址:" + mIpAddress);
  System.out.println("获取数据时间:" + dDateTime);
}
public static void main(String[] args) {
  MonitorServiceImpl.information();
}
}
用于日期计算
import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/*该类用于数据库日期的运算*/
public class CountDate {
/**
*/
private String currentMonth;
private String nextMonth;
private String currentYear;
private String nextYear;
private String currentYM;
private String currentYMDHMS;
private Date currentYMDHMSs;
private String nextYMDHMS;
/* 根据系统日期获得当月 */
public String getCurrentMonth() {
  Calendar rightNow = Calendar.getInstance();
  if (String.valueOf(rightNow.get(Calendar.MONTH) + 1).length() > 1) {
   this.currentMonth = String
     .valueOf(rightNow.get(Calendar.MONTH) + 1);
   return currentMonth;
  }
  this.currentMonth = "0"
    + String.valueOf(rightNow.get(Calendar.MONTH) + 1);
  return currentMonth;
}
/* 根据系统日期获得当年 */
public String getCurrentYear() {
  Calendar rightNow = Calendar.getInstance();
  this.currentYear = String.valueOf(rightNow.get(Calendar.YEAR));
  return currentYear;
}
/* 根据系统日期获得数据库日期 */
public String getCurrentYMDHMS() {
  SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  Timestamp t = new Timestamp(Calendar.getInstance().getTimeInMillis());
  this.currentYMDHMS = sdf.format(t);
  return currentYMDHMS;
}
public Date getCurrentYMDHMSs() {
  Timestamp t = new Timestamp(Calendar.getInstance().getTimeInMillis());
  currentYMDHMSs = t;
  return currentYMDHMSs;
}
/* 根据系统日期获得下个月 */
public String getNextMonth() {
  Calendar rightNow = Calendar.getInstance();
  if ((rightNow.get(Calendar.MONTH) + 1) == 12) {
   this.nextMonth = "01";
   this.nextYear = String.valueOf(rightNow.get(Calendar.YEAR) + 1);
   return nextMonth;
  }
  if (String.valueOf(rightNow.get(Calendar.MONTH) + 2).length() > 1) {
   this.nextMonth = String.valueOf(rightNow.get(Calendar.MONTH) + 2);
   return nextMonth;
  }
  this.nextMonth = "0" + String.valueOf(rightNow.get(Calendar.MONTH) + 2);
  return nextMonth;
}
/* 根据系统日期获得下个月的年分 */
public String getNextYear() {
  Calendar rightNow = Calendar.getInstance();
  if ((rightNow.get(Calendar.MONTH) + 1) == 12) {
   this.nextMonth = "01";
   this.nextYear = String.valueOf(rightNow.get(Calendar.YEAR) + 1);
   return nextYear;
  }
  this.nextYear = String.valueOf(rightNow.get(Calendar.YEAR));
  return nextYear;
}
/* 根据系统日期获得下个月的数据库日期 */
public String getNextYMDHMS() {
  nextYear = getNextYear();
  nextMonth = getNextMonth();
  this.nextYMDHMS = nextYear + "-" + nextMonth + "-" + "01 00:00:00";
  return nextYMDHMS;
}
/* 根据给定的月参数获得当月日期 */
public String getCurrentMonth(int pcurrentMonth) {
  if (pcurrentMonth % 12 > 1 || (pcurrentMonth % 12 == 1)) {
   if (String.valueOf((pcurrentMonth % 12)).length() > 1) {
    this.currentMonth = String.valueOf((pcurrentMonth % 12));
   } else {
    this.currentMonth = "0" + String.valueOf((pcurrentMonth % 12));
    return currentMonth;
   }
  }
  if (String.valueOf(pcurrentMonth).length() > 1) {
   this.currentMonth = String.valueOf(pcurrentMonth);
  } else {
   this.currentMonth = "0" + String.valueOf(pcurrentMonth);
  }
  return currentMonth;
}
/* 根据给定的月参数和年参数获得当年 */
public String getCurrentYear(int pcurrentMonth, int pcurrentYear) {
  if (pcurrentMonth % 12 > 1 || (pcurrentMonth % 12 == 1)) {
   if (String.valueOf((pcurrentMonth % 12)).length() > 1) {
    this.currentMonth = String.valueOf((pcurrentMonth % 12));
   } else {
    this.currentMonth = "0" + String.valueOf((pcurrentMonth % 12));
   }
   this.currentYear = String
     .valueOf(pcurrentMonth / 12 + pcurrentYear);
   return currentYear;
  }
  return this.currentYear = String.valueOf(pcurrentYear);
}
/* 根据给定的月参数和年参数获得数据库日期 */
public String getCurrentYMDHMS(int pcurrentMonth, int pcurrentYear) {
  if ((pcurrentMonth % 12 > 1) || (pcurrentMonth % 12 == 1)) {
   if (String.valueOf((pcurrentMonth % 12)).length() > 1) {
    this.currentMonth = String.valueOf((pcurrentMonth % 12));
   } else {
    this.currentMonth = "0" + String.valueOf((pcurrentMonth % 12));
   }
   this.currentYear = String
     .valueOf(pcurrentMonth / 12 + pcurrentYear);
   this.currentYMDHMS = currentYear + "-" + currentMonth + "-"
     + "01 00:00:00";
   return currentYMDHMS;
  }
  if (String.valueOf(pcurrentMonth).length() > 1) {
   this.currentMonth = String.valueOf(pcurrentMonth);
  } else {
   this.currentMonth = "0" + String.valueOf(pcurrentMonth);
  }
  this.currentYear = String.valueOf(pcurrentYear);
  this.currentYMDHMS = currentYear + "-" + currentMonth + "-"
    + "01 00:00:00";
  return currentYMDHMS;
}
public Date getCurrentYMDHMSs(int pcurrentMonth, int pcurrentYear) {
  if (pcurrentMonth % 12 > 1 || (pcurrentMonth % 12 == 1)) {
   if (String.valueOf((pcurrentMonth % 12)).length() > 1) {
    this.currentMonth = String.valueOf((pcurrentMonth % 12));
   } else {
    this.currentMonth = "0" + String.valueOf((pcurrentMonth % 12));
   }
   this.currentYear = String
     .valueOf(pcurrentMonth / 12 + pcurrentYear);
   this.currentYMDHMSs = Timestamp.valueOf(currentYear + "-"
     + currentMonth + "-" + "01 00:00:00.0");
   return currentYMDHMSs;
  }
  if (String.valueOf(pcurrentMonth).length() > 1) {
   this.currentMonth = String.valueOf(pcurrentMonth);
  } else {
   this.currentMonth = "0" + String.valueOf(pcurrentMonth);
  }
  this.currentYear = String.valueOf(pcurrentYear);
  this.currentYMDHMSs = Timestamp.valueOf(currentYear + "-"
    + currentMonth + "-" + "01 00:00:00.0");
  return currentYMDHMSs;
}
/* 根据给定的月参数和年参数获得下个月的月份和年份 */
public String getNextYMDHMS(int pcurrentMonth, int pcurrentYear) {
  if ((pcurrentMonth % 12 > 1) || (pcurrentMonth % 12 == 1)) {
   if (String.valueOf((pcurrentMonth % 12)).length() > 1) {
    this.currentMonth = String.valueOf((pcurrentMonth % 12));
   } else {
    this.currentMonth = "0" + String.valueOf((pcurrentMonth % 12));
   }
   this.currentYear = String
     .valueOf(pcurrentMonth / 12 + pcurrentYear);
   if (String.valueOf(Integer.parseInt(currentMonth) + 1).length() > 1) {
    this.nextMonth = String
      .valueOf(Integer.parseInt(currentMonth) + 1);
   } else {
    this.nextMonth = "0"
      + String.valueOf(Integer.parseInt(currentMonth) + 1);
   }
   this.nextYear = currentYear;
   this.nextYMDHMS = nextYear + "-" + nextMonth + "-" + "01 00:00:00";
   return nextYMDHMS;
  }
  if (pcurrentMonth == 12) {
   this.nextMonth = "01";
   this.nextYear = String.valueOf(pcurrentYear + 1);
   this.nextYMDHMS = nextYear + "-" + nextMonth + "-" + "01 00:00:00";
   return nextYMDHMS;
  }
  if (String.valueOf(pcurrentMonth + 1).length() > 1) {
   this.nextMonth = String.valueOf(pcurrentMonth + 1);
   this.nextYear = String.valueOf(pcurrentYear);
   this.nextYMDHMS = nextYear + "-" + nextMonth + "-" + "01 00:00:00";
   return nextYMDHMS;
  }
  this.nextMonth = "0" + String.valueOf(pcurrentMonth + 1);
  this.nextYear = String.valueOf(pcurrentYear);
  this.nextYMDHMS = nextYear + "-" + nextMonth + "-" + "01 00:00:00";
  return nextYMDHMS;
}
/* 根据系统日期获得下个月的年份和月份 */
public String getCurrentYM() {
  SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月");
  Timestamp t = new Timestamp(Calendar.getInstance().getTimeInMillis());
  this.currentYM = sdf.format(t);
  return currentYM;
}
/* 根据系统日期获得当月的年份和月份 */
public String getCurrentYM(int pcurrentMonth, int pcurrentYear) {
  if (pcurrentMonth % 12 > 1 || (pcurrentMonth % 12 == 1)) {
   if (String.valueOf(pcurrentMonth % 12).length() > 1) {
    this.currentMonth = String.valueOf((pcurrentMonth % 12));
   } else {
    this.currentMonth = "0" + String.valueOf((pcurrentMonth % 12));
   }
   this.currentYear = String
     .valueOf(pcurrentMonth / 12 + pcurrentYear);
   this.currentYM = currentYear + "年" + currentMonth + "月";
   return currentYM;
  }
  if (String.valueOf(pcurrentMonth).length() > 1) {
   this.currentMonth = String.valueOf(pcurrentMonth);
  } else {
   this.currentMonth = "0" + String.valueOf(pcurrentMonth);
  }
  this.currentYear = String.valueOf(pcurrentYear);
  this.currentYM = currentYear + "年" + currentMonth + "月";
  return currentYM;
}
/*
  * public static void main(String args[]){ CountDate c = new CountDate();
  *
  * System.out.println(c.getCurrentYMDHMSs(12, 2029)); }
  */
}
保存信息的javaBean
import java.sql.Timestamp;
/*采集系统存取数据JavaBean*/
public class MonitorInfoBean implements Comparable<MonitorInfoBean> {
/** 操作系统. */
private String osName;
/** 总的物理内存. */
private float totalMemorySize;
/** 已使用的物理内存. */
private float usedMemory;
/** cpu使用率. */
private double cpuRatio;
/** 主机IP地址 */
private String mIpAddress;
/** 数据存储时间 */
private String dDateTime;
/** 内存使用率 */
private float memoryRatio;
/** linux下Buffers内存 */
private float buffersMemory;
/** linux下Cached内存 */
private float cachedMemory;
public float getBuffersMemory() {
  return buffersMemory;
}
public float getCachedMemory() {
  return cachedMemory;
}
public String getDDateTime() {
  return dDateTime;
}
public void setDDateTime(String dateTime) {
  dDateTime = dateTime;
}
public String getMIpAddress() {
  return mIpAddress;
}
public void setMIpAddress(String ipAddress) {
  mIpAddress = ipAddress;
}
public String getOsName() {
  return osName;
}
public void setOsName(String osName) {
  this.osName = osName;
}
public float getTotalMemorySize() {
  return totalMemorySize;
}
public void setTotalMemorySize(float totalMemorySize) {
  this.totalMemorySize = totalMemorySize;
}
public float getUsedMemory() {
  return usedMemory;
}
public void setUsedMemory(long usedMemory) {
  this.usedMemory = usedMemory;
}
public double getCpuRatio() {
  return cpuRatio;
}
public void setCpuRatio(double cpuRatio) {
  this.cpuRatio = cpuRatio;
}
public int compareTo(MonitorInfoBean m) {
  String stra = this.getDDateTime();
  String strb = m.getDDateTime();
  Timestamp a = Timestamp.valueOf(stra);
  Timestamp b = Timestamp.valueOf(strb);
  if (a.before(b)) {
   return -1;
  } else if (a.after(b)) {
   return 1;
  } else {
   return 0;
  }
}
public float getMemoryRatio() {
  return memoryRatio;
}
public void setMemoryRatio(float memoryRatio) {
  this.memoryRatio = memoryRatio;
}
public void setUsedMemory(float usedMemory) {
  this.usedMemory = usedMemory;
}
public void setBuffersMemory(float buffersMemory) {
  this.buffersMemory = buffersMemory;
}
public void setCachedMemory(float cachedMemory) {
  this.cachedMemory = cachedMemory;
}
}