java获取cpu,内存,磁盘等信息

原文：java获取cpu,内存,磁盘等信息

源代码下载地址：http://www.zuidaima.com/share/1550463331306496.htm

package com.zuidaima.util;
import java.io.File;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.util.ArrayList;
import java.util.List; 

import sun.management.ManagementFactory;

import com.sun.management.OperatingSystemMXBean;

/**
* 获取windows系统信息（CPU,内存,文件系统）
* @author www.zuidaima.com
*
*/ 

public class cpu {
    private static final int CPUTIME = 500;
    private static final int PERCENT = 100;
    private static final int FAULTLENGTH = 10; 

    public static void main(String[] args) {
    System.out.println(getCpuRatioForWindows());
    System.out.println(getMemery());
    System.out.println(getDisk());
} 

//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();
  System.out.println("总  的  内 存"+(totalvirtualMemory/1024.0/1024.0/1024.0));
  System.out.println("使用的内存"+((totalvirtualMemory-freePhysicalMemorySize)/1024.0/1024.0/1024.0));
  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：
   * @author www.zuidaima.com
   * @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;
  }
}