java获取cpu使用率/内存使用率/硬盘的使用率

import java.io.File;

import java.io.InputStreamReader;

import java.io.LineNumberReader;

import java.lang.management.ManagementFactory;

import java.util.ArrayList;

import java.util.List;

import com.sun.management.OperatingSystemMXBean;

/**

* 获取windows系统信息（CPU,内存,文件系统）

*

* @author libing

*

*/

public class WindowsInfoUtil {

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();

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：

*

* @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;

}

}