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作者是 阿蜜果
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2008-05-04 07:02:04 |
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在Java中,可以获得总的物理内存、剩余的物理内存、已使用的物理内存等信息,本例讲解如何取得这些信息,并且获得在Windows下的内存使用率。
首先编写一个MonitorInfoBean类,用来装载监控的一些信息,包括物理内存、剩余的物理内存、已使用的物理内存、内存使用率等字段,该类的代码如下:
package com.amigo.performance;

 /** *//**
* 监视信息的JavaBean类.
* @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;
}
}

接着编写一个获得当前的监控信息的接口,该类的代码如下所示:
package com.amigo.performance;

 /** *//**
* 获取系统信息的业务逻辑类接口.
* @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 {
 /** *//**
* 获得当前的监控对象.
* @return 返回构造好的监控对象
* @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;

}
该类的实现类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;

 /** *//**
* 获取系统信息的业务逻辑实现类.
* @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;

 /** *//**
* 获得当前的监控对象.
* @return 返回构造好的监控对象
* @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();
}
// 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;
}

 /** *//**
* 获得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
* @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")) |