Get current JVM data

 Get current jvm data 

import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.lang.management.ManagementFactory;

import org.apache.log4j.Logger;

import com.sun.management.OperatingSystemMXBean;

public class MonitorUtil {
    private static final Logger logger = Logger.getLogger(MonitorUtil.class);
    // It can be set longer , Prevent reading the cpu Occupancy rate , It's not allowed   
    private static final int CPUTIME = 5000;  
  
    private static final int PERCENT = 100;  
  
    private static final int FAULTLENGTH = 10;  
  
    /** *//** 
     *  Get the current monitoring object . 
     */  
    public static String getMonitorInfoBean() throws Exception {  
        int kb = 1024;  
          
        //  Available memory   
        long totalMemory = Runtime.getRuntime().totalMemory() / kb;  
        //  The remaining memory   
        long freeMemory = Runtime.getRuntime().freeMemory() / kb;  
        //  Maximum available memory   
        long maxMemory = Runtime.getRuntime().maxMemory() / kb;  
  
        OperatingSystemMXBean osmxb = (OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();  
  
        //  operating system   
        String osName = System.getProperty("os.name");  
        //  Total physical memory   
        long totalMemorySize = osmxb.getTotalPhysicalMemorySize() / kb;  
        //  Remaining physical memory   
        long freePhysicalMemorySize = osmxb.getFreePhysicalMemorySize() / kb;  
        //  Physical memory used   
        long usedMemory = (osmxb.getTotalPhysicalMemorySize() - osmxb  
                .getFreePhysicalMemorySize())  
                / kb;  
  
        //  Get the total number of threads   
        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 = getCpuRatioForWindows();  
        }  
          
        StringBuffer sb = new StringBuffer();
        double total = (Runtime.getRuntime().totalMemory()) / (1024.0 * 1024);
        double max = (Runtime.getRuntime().maxMemory()) / (1024.0 * 1024);
        double free = (Runtime.getRuntime().freeMemory()) / (1024.0 * 1024);
        logger.info("Java  The maximum amount of memory a virtual machine tries to use ( At present JVM Maximum available memory ) maxMemory(): " + max + "MB<br/>");
        logger.info("Java  Total memory in the virtual machine ( At present JVM Total amount of memory occupied ) totalMemory(): " + total + "MB<br/>");
        logger.info("Java  The amount of free memory in a virtual machine ( At present JVM Free memory ) freeMemory(): " + free + "MB<br/>");
        logger.info(" because JVM Use physical memory only when memory is needed , therefore freeMemory() The value of is usually very small ,<br/>" +
        " and JVM The actual available memory is not equal to freeMemory(), It should be equal to  maxMemory() - totalMemory() + freeMemory().<br/>");
        logger.info("JVM Actually available memory : " + (max - total + free) + "MB<br/>");
        logger.info("cpu Occupancy rate =" + cpuRatio+"/n");
        logger.info(" Available memory =" + totalMemory+"/n");  
        logger.info(" The remaining memory =" + freeMemory+"/n");  
        logger.info(" Maximum available memory =" + maxMemory+"/n");  
          
        logger.info(" operating system =" + osName+"/n");  
        logger.info(" Total physical memory =" + totalMemorySize + "kb/n");  
        logger.info(" Remaining physical memory =" + freeMemory + "kb/n");  
        logger.info(" Physical memory used =" + usedMemory + "kb/n");  
        logger.info(" Total threads =" + totalThread+ "/n");  
        return sb.toString();  
    }  
  
    /** *//** 
     *  get CPU Usage rate . 
     */  
    private static double getCpuRatioForWindows() {  
        try {  
            String procCmd = System.getenv("windir")  
                    + "\\system32\\wbem\\wmic.exe process get Caption,CommandLine,"  
                    + "KernelModeTime,ReadOperationCount,ThreadCount,UserModeTime,WriteOperationCount";  
            //  Fetch process information   
            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;  
        }  
    }  
  
    /** *//** 
     *  Read CPU Information . 
   */  
    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;  
                }  
                //  Field order ：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;  
                }  
                // log.info("line="+line);  
                if (caption.equals("System Idle Process")  
                        || caption.equals("System")) {  
                    idletime += Long.valueOf(  
                            substring(line, kmtidx, rocidx - 1).trim())  
                            .longValue();  
                    idletime += Long.valueOf(  
                            substring(line, umtidx, wocidx - 1).trim())  
                            .longValue();  
                    continue;  
                }  
  
                kneltime += Long.valueOf(  
                        substring(line, kmtidx, rocidx - 1).trim())  
                        .longValue();  
                usertime += Long.valueOf(  
                        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;  
    }  
        /** *//** 
         *  because String.subString There are problems in the processing of Chinese characters ： 
         * @param src  String to intercept  
         * @param start_idx  Start coordinates （ Include this coordinate ) 
         * @param end_idx    Cut off coordinate （ Include this coordinate ） 
         * @return 
         */  
        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;  
        }  
   }