利用java获取计算机cpu利用率和内存使用信息
1.pojo类:
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;
}
}2. 实现类:
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.util.StringTokenizer;import sun.management.ManagementFactory;
import com.sun.management.OperatingSystemMXBean;
public class cpu {
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;
public double getCpuRatio(){
// 操作系统
String osName = System.getProperty("os.name");
double cpuRatio = 0;
if (osName.toLowerCase().startsWith("windows")) {
return cpuRatio = this.getCpuRatioForWindows();
}
else {
return cpuRatio = this.getCpuRateForLinux();
}
}
/**
* 获得当前的监控对象.
* @return 返回构造好的监控对象
*/
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
*/
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
*/
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
*/
public static void main(String[] args) throws Exception {
cpu c =new cpu();
System.out.println("cpu占有率1=" + c.getCpuRatio());
System.out.println("cpu占有率2=" + c.getCpuRatioForWindows());
MonitorInfoBean monitorInfo = c.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");
}
}
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;
}
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