在Java中，可以獲得總的物理內存、剩余的物理內存、已使用的物理內存等信息，本例講解如何取得這些信息，并且獲得在Windows下的內存使用率。
首先編寫一個MonitorInfoBean類，用來裝載監控的一些信息，包括物理內存、剩余的物理內存、已使用的物理內存、內存使用率等字段，該類的代碼如下：
package com.amigo.performance;
/** *//**
* 監視信息的JavaBean類.
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* @version 1.0
* Creation date: 2008-4-25 - 上午10:37:00
*/
public class MonitorInfoBean 
{
/** *//** 可使用內存. */
private long totalMemory;
/** *//** 剩余內存. */
private long freeMemory;
/** *//** 最大可使用內存. */
private long maxMemory;
/** *//** 操作系統. */
private String osName;
/** *//** 總的物理內存. */
private long totalMemorySize;
/** *//** 剩余的物理內存. */
private long freePhysicalMemorySize;
/** *//** 已使用的物理內存. */
private long usedMemory;
/** *//** 線程總數. */
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;
}
}
接著編寫一個獲得當前的監控信息的接口，該類的代碼如下所示：
package com.amigo.performance;
/** *//**
* 獲取系統信息的業務邏輯類接口.
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* @version 1.0
* Creation date: 2008-3-11 - 上午10:06:06
*/
public interface IMonitorService {
/** *//**
* 獲得當前的監控對象.
* @return 返回構造好的監控對象
* @throws Exception
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* Creation date: 2008-4-25 - 上午10:45:08
*/
public MonitorInfoBean getMonitorInfoBean() throws Exception;
}
該類的實現類MonitorServiceImpl如下所示：
package com.amigo.performance;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import sun.management.ManagementFactory;
import com.sun.management.OperatingSystemMXBean;
/** *//**
* 獲取系統信息的業務邏輯實現類.
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* @version 1.0 Creation date: 2008-3-11 - 上午10:06:06
*/
public class MonitorServiceImpl implements IMonitorService {
private static final int CPUTIME = 30;
private static final int PERCENT = 100;
private static final int FAULTLENGTH = 10;
/** *//**
* 獲得當前的監控對象.
* @return 返回構造好的監控對象
* @throws Exception
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* Creation date: 2008-4-25 - 上午10:45:08
*/
public MonitorInfoBean getMonitorInfoBean() throws Exception {
int kb = 1024;
// 可使用內存
long totalMemory = Runtime.getRuntime().totalMemory() / kb;
// 剩余內存
long freeMemory = Runtime.getRuntime().freeMemory() / kb;
// 最大可使用內存
long maxMemory = Runtime.getRuntime().maxMemory() / kb;
OperatingSystemMXBean osmxb = (OperatingSystemMXBean) ManagementFactory
.getOperatingSystemMXBean();
// 操作系統
String osName = System.getProperty("os.name");
// 總的物理內存
long totalMemorySize = osmxb.getTotalPhysicalMemorySize() / kb;
// 剩余的物理內存
long freePhysicalMemorySize = osmxb.getFreePhysicalMemorySize() / kb;
// 已使用的物理內存
long usedMemory = (osmxb.getTotalPhysicalMemorySize() - osmxb
.getFreePhysicalMemorySize())
/ kb;
// 獲得線程總數
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();
}
// 構造返回對象
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;
}
/** *//**
* 獲得CPU使用率.
* @return 返回cpu使用率
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* Creation date: 2008-4-25 - 下午06:05:11
*/
private double getCpuRatioForWindows() {
try {
String procCmd = System.getenv("windir")
+ "\\system32\\wbem\\wmic.exe process get Caption,CommandLine,"
+ "KernelModeTime,ReadOperationCount,ThreadCount,UserModeTime,WriteOperationCount";
// 取進程信息
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;
}
}
/** *//**
* 讀取CPU信息.
* @param proc
* @return
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* Creation date: 2008-4-25 - 下午06:10:14
*/
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;
}
// 字段出現順序：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;
}
/** *//**
* 測試方法.
* @param args
* @throws Exception
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* Creation date: 2008-4-30 - 下午04:47:29
*/
public static void main(String[] args) throws Exception {
IMonitorService service = new MonitorServiceImpl();
MonitorInfoBean monitorInfo = service.getMonitorInfoBean();
System.out.println("cpu占有率=" + monitorInfo.getCpuRatio());
System.out.println("可使用內存=" + monitorInfo.getTotalMemory());
System.out.println("剩余內存=" + monitorInfo.getFreeMemory());
System.out.println("最大可使用內存=" + monitorInfo.getMaxMemory());
System.out.println("操作系統=" + monitorInfo.getOsName());
System.out.println("總的物理內存=" + monitorInfo.getTotalMemorySize() + "kb");
System.out.println("剩余的物理內存=" + monitorInfo.getFreeMemory() + "kb");
System.out.println("已使用的物理內存=" + monitorInfo.getUsedMemory() + "kb");
System.out.println("線程總數=" + monitorInfo.getTotalThread() + "kb");
}
}
該實現類中需要用到一個自己編寫byte的工具類，該類的代碼如下所示：
package com.amigo.performance;
/** *//**
* byte操作類.
* @author <a href="mailto:xiexingxing1121@126.com">AmigoXie</a>
* @version 1.0
* Creation date: 2008-4-30 - 下午04:57:23
*/
public class Bytes {
/** *//**
* 由于String.subString對漢字處理存在問題（把一個漢字視為一個字節)，因此在
* 包含漢字的字符串時存在隱患，現調整如下：
* @param src 要截取的字符串
* @param start_idx 開始坐標（包括該坐標)
* @param end_idx 截止坐標（包括該坐標）
* @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;
}
}
運行下MonitorBeanImpl類，讀者將會看到當前的內存、cpu利用率等信息。
posted on 2008-04-30 17:15
阿蜜果 閱讀(4484)
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