java获取系统信息,不用jni

╰半夏微凉° 2022-06-11 03:51 156阅读 0赞

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，下面例子可以取得这些信息，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：

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package com.hmw.system.monitor;  
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;  
\}  
\}

package com.hmw.system.monitor;  
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：

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package com.hmw.system.monitor;  
/\*\*  
\* 获取系统信息的业务逻辑类接口.  
\*/  
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  
\*/  
public MonitorInfoBean getMonitorInfoBean() throws Exception;  
\}

package com.hmw.system.monitor;  
/\*\*  
\* 获取系统信息的业务逻辑类接口.  
\*/  
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  
\*/  
public MonitorInfoBean getMonitorInfoBean() throws Exception;  
\}  
该类的实现类MonitorServiceImpl如下所示：

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package com.hmw.system.monitor;  
import java.io.BufferedReader;  
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;  
/\*\*  
\*  
\* 获取系统信息的业务逻辑实现类.  
\*  
\* @author GuoHuang  
\*/  
public class MonitorServiceImpl implements IMonitorService \{  
private static final int CPUTIME = 30;  
private static final int PERCENT = 100;  
private static final int FAULTLENGTH = 10;  
private static String linuxVersion = null;  
/\*\*  
\* 获得当前的监控对象.  
\*  
\* @return 返回构造好的监控对象  
\* @throws Exception  
\* @author GuoHuang  
\*/  
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 = 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  
\* @author GuoHuang  
\*/  
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 GuoHuang  
\*/  
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;  
\}  
String s1 = Bytes.substring(line, kmtidx, rocidx - 1).trim();  
String s2 = Bytes.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;  
\}  
/\*\*  
\* 测试方法.  
\*  
\* @param args  
\* @throws Exception  
\* @author GuoHuang  
\*/  
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");  
\}  
\}

package com.hmw.system.monitor;  
import java.io.BufferedReader;  
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;  
/\*\*  
\*  
\* 获取系统信息的业务逻辑实现类.  
\*  
\* @author GuoHuang  
\*/  
public class MonitorServiceImpl implements IMonitorService \{  
private static final int CPUTIME = 30;  
private static final int PERCENT = 100;  
private static final int FAULTLENGTH = 10;  
private static String linuxVersion = null;  
/\*\*  
\* 获得当前的监控对象.  
\*  
\* @return 返回构造好的监控对象  
\* @throws Exception  
\* @author GuoHuang  
\*/  
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 = 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  
\* @author GuoHuang  
\*/  
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 GuoHuang  
\*/  
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;  
\}  
String s1 = Bytes.substring(line, kmtidx, rocidx - 1).trim();  
String s2 = Bytes.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;  
\}  
/\*\*  
\* 测试方法.  
\*  
\* @param args  
\* @throws Exception  
\* @author GuoHuang  
\*/  
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");  
\}  
\}  
该实现类中需要用到一个自己编写byte的工具类，该类的代码如下所示：

view plaincopy to clipboardprint?  
package com.hmw.system.monitor;  
/\*\*  
\* byte操作类.  
\*/  
public class Bytes \{  
/\*\*  
\* 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  
\*/  
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;  
\}  
\}

package com.hmw.system.monitor;  
/\*\*  
\* byte操作类.  
\*/  
public class Bytes \{  
/\*\*  
\* 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  
\*/  
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;  
\}  
\}  
运行下MonitorBeanImpl类，读者将会看到当前的内存、cpu利用率等信息。

=================================================================================================================================================

1.  **package** com.amgkaka.performance; 
2.  
3.  /\*\* \*//\*\*
4.   \* 监视信息的JavaBean类.
5.   \* @author amg
6.   \* @version 1.0 
7.   \* Creation date: 2008-4-25 - 上午10:37:00
8.   \*/
9.  **public****class** MonitorInfoBean \{ 
10. /\*\* \*//\*\* 可使用内存. \*/
11. **private****long** totalMemory; 
12. 
13. /\*\* \*//\*\* 剩余内存. \*/
14. **private****long** freeMemory; 
15. 
16. /\*\* \*//\*\* 最大可使用内存. \*/
17. **private****long** maxMemory; 
18. 
19. /\*\* \*//\*\* 操作系统. \*/
20. **private** String osName; 
21. 
22. /\*\* \*//\*\* 总的物理内存. \*/
23. **private****long** totalMemorySize; 
24. 
25. /\*\* \*//\*\* 剩余的物理内存. \*/
26. **private****long** freePhysicalMemorySize; 
27. 
28. /\*\* \*//\*\* 已使用的物理内存. \*/
29. **private****long** usedMemory; 
30. 
31. /\*\* \*//\*\* 线程总数. \*/
32. **private****int** totalThread; 
33. 
34. /\*\* \*//\*\* cpu使用率. \*/
35. **private****double** cpuRatio; 
36. 
37. **public****long** getFreeMemory() \{ 
38. **return** freeMemory; 
39.  \} 
40. 
41. **public****void** setFreeMemory(**long** freeMemory) \{ 
42. **this**.freeMemory = freeMemory; 
43.  \} 
44. 
45. **public****long** getFreePhysicalMemorySize() \{ 
46. **return** freePhysicalMemorySize; 
47.  \} 
48. 
49. **public****void** setFreePhysicalMemorySize(**long** freePhysicalMemorySize) \{ 
50. **this**.freePhysicalMemorySize = freePhysicalMemorySize; 
51.  \} 
52. 
53. **public****long** getMaxMemory() \{ 
54. **return** maxMemory; 
55.  \} 
56. 
57. **public****void** setMaxMemory(**long** maxMemory) \{ 
58. **this**.maxMemory = maxMemory; 
59.  \} 
60. 
61. **public** String getOsName() \{ 
62. **return** osName; 
63.  \} 
64. 
65. **public****void** setOsName(String osName) \{ 
66. **this**.osName = osName; 
67.  \} 
68. 
69. **public****long** getTotalMemory() \{ 
70. **return** totalMemory; 
71.  \} 
72. 
73. **public****void** setTotalMemory(**long** totalMemory) \{ 
74. **this**.totalMemory = totalMemory; 
75.  \} 
76. 
77. **public****long** getTotalMemorySize() \{ 
78. **return** totalMemorySize; 
79.  \} 
80. 
81. **public****void** setTotalMemorySize(**long** totalMemorySize) \{ 
82. **this**.totalMemorySize = totalMemorySize; 
83.  \} 
84. 
85. **public****int** getTotalThread() \{ 
86. **return** totalThread; 
87.  \} 
88. 
89. **public****void** setTotalThread(**int** totalThread) \{ 
90. **this**.totalThread = totalThread; 
91.  \} 
92. 
93. **public****long** getUsedMemory() \{ 
94. **return** usedMemory; 
95.  \} 
96. 
97. **public****void** setUsedMemory(**long** usedMemory) \{ 
98. **this**.usedMemory = usedMemory; 
99.  \} 
100. 
101. **public****double** getCpuRatio() \{ 
102. **return** cpuRatio; 
103.  \} 
104. 
105. **public****void** setCpuRatio(**double** cpuRatio) \{ 
106. **this**.cpuRatio = cpuRatio; 
107.  \} 
108. \}

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：

Java代码 ![收藏代码][icon_star.png]

1.  **package** com.amgkaka.performance; 
2.  
3.  /\*\* \*//\*\*
4.   \* 获取系统信息的业务逻辑类接口.
5.   \* @author amg \* @version 1.0 
6.   \* Creation date: 2008-3-11 - 上午10:06:06
7.   \*/
8.  **public****interface** IMonitorService \{ 
9.  /\*\* \*//\*\*
10.  \* 获得当前的监控对象.
11.  \* @return 返回构造好的监控对象
12.  \* @throws Exception
13.  \* @author amgkaka
14.  \* Creation date: 2008-4-25 - 上午10:45:08
15.  \*/
16. **public** MonitorInfoBean getMonitorInfoBean() **throws** Exception; 
17. 
18. \}

该类的实现类MonitorServiceImpl如下所示：

Java代码 ![收藏代码][icon_star.png]

1.  **package** com.amgkaka.performance; 
2.  
3.  **import** java.io.InputStreamReader; 
4.  **import** java.io.LineNumberReader; 
5.  
6.  **import** sun.management.ManagementFactory; 
7.  
8.  **import** com.sun.management.OperatingSystemMXBean; 
9.  
10. /\*\* \*//\*\*
11.  \* 获取系统信息的业务逻辑实现类.
12.  \* @author amg \* @version 1.0 Creation date: 2008-3-11 - 上午10:06:06
13.  \*/
14. **public****class** MonitorServiceImpl **implements** IMonitorService \{ 
15. //可以设置长些，防止读到运行此次系统检查时的cpu占用率，就不准了
16. **private****static****final****int** CPUTIME = 5000; 
17. 
18. **private****static****final****int** PERCENT = 100; 
19. 
20. **private****static****final****int** FAULTLENGTH = 10; 
21. 
22. /\*\* \*//\*\*
23.  \* 获得当前的监控对象.
24.  \* @return 返回构造好的监控对象
25.  \* @throws Exception
26.  \* @author amg \* Creation date: 2008-4-25 - 上午10:45:08
27.  \*/
28. **public** MonitorInfoBean getMonitorInfoBean() **throws** Exception \{ 
29. **int** kb = 1024; 
30. 
31. // 可使用内存
32. **long** totalMemory = Runtime.getRuntime().totalMemory() / kb; 
33. // 剩余内存
34. **long** freeMemory = Runtime.getRuntime().freeMemory() / kb; 
35. // 最大可使用内存
36. **long** maxMemory = Runtime.getRuntime().maxMemory() / kb; 
37. 
38.  OperatingSystemMXBean osmxb = (OperatingSystemMXBean) ManagementFactory 
39.  .getOperatingSystemMXBean(); 
40. 
41. // 操作系统
42.  String osName = System.getProperty("os.name"); 
43. // 总的物理内存
44. **long** totalMemorySize = osmxb.getTotalPhysicalMemorySize() / kb; 
45. // 剩余的物理内存
46. **long** freePhysicalMemorySize = osmxb.getFreePhysicalMemorySize() / kb; 
47. // 已使用的物理内存
48. **long** usedMemory = (osmxb.getTotalPhysicalMemorySize() - osmxb 
49.  .getFreePhysicalMemorySize()) 
50.  / kb; 
51. 
52. // 获得线程总数
53.  ThreadGroup parentThread; 
54. **for** (parentThread = Thread.currentThread().getThreadGroup(); parentThread 
55.  .getParent() != **null**; parentThread = parentThread.getParent()) 
56.  ; 
57. **int** totalThread = parentThread.activeCount(); 
58. 
59. **double** cpuRatio = 0; 
60. **if** (osName.toLowerCase().startsWith("windows")) \{ 
61.  cpuRatio = **this**.getCpuRatioForWindows(); 
62.  \} 
63. 
64. // 构造返回对象
65.  MonitorInfoBean infoBean = **new** MonitorInfoBean(); 
66.  infoBean.setFreeMemory(freeMemory); 
67.  infoBean.setFreePhysicalMemorySize(freePhysicalMemorySize); 
68.  infoBean.setMaxMemory(maxMemory); 
69.  infoBean.setOsName(osName); 
70.  infoBean.setTotalMemory(totalMemory); 
71.  infoBean.setTotalMemorySize(totalMemorySize); 
72.  infoBean.setTotalThread(totalThread); 
73.  infoBean.setUsedMemory(usedMemory); 
74.  infoBean.setCpuRatio(cpuRatio); 
75. **return** infoBean; 
76.  \} 
77. 
78. /\*\* \*//\*\*
79.  \* 获得CPU使用率.
80.  \* @return 返回cpu使用率
81.  \* @author amg \* Creation date: 2008-4-25 - 下午06:05:11
82.  \*/
83. **private****double** getCpuRatioForWindows() \{ 
84. **try** \{ 
85.  String procCmd = System.getenv("windir") 
86.  \+ "\\\\system32\\\\wbem\\\\wmic.exe process get Caption,CommandLine,"
87.  \+ "KernelModeTime,ReadOperationCount,ThreadCount,UserModeTime,WriteOperationCount"; 
88. // 取进程信息
89. **long**\[\] c0 = readCpu(Runtime.getRuntime().exec(procCmd)); 
90.  Thread.sleep(CPUTIME); 
91. **long**\[\] c1 = readCpu(Runtime.getRuntime().exec(procCmd)); 
92. **if** (c0 != **null** && c1 != **null**) \{ 
93. **long** idletime = c1\[0\] - c0\[0\]; 
94. **long** busytime = c1\[1\] - c0\[1\]; 
95. **return** Double.valueOf( 
96.  PERCENT \* (busytime) / (busytime + idletime)) 
97.  .doubleValue(); 
98.  \} **else** \{ 
99. **return**0.0; 
100.  \} 
101.  \} **catch** (Exception ex) \{ 
102.  ex.printStackTrace(); 
103. **return**0.0; 
104.  \} 
105.  \} 
106. 
107. /\*\* \*//\*\*
108.  \* 读取CPU信息.
109.  \* @param proc
110.  \* @return
111.  \* @author amg \* Creation date: 2008-4-25 - 下午06:10:14
112.  \*/
113. **private****long**\[\] readCpu(**final** Process proc) \{ 
114. **long**\[\] retn = **new****long**\[2\]; 
115. **try** \{ 
116.  proc.getOutputStream().close(); 
117.  InputStreamReader ir = **new** InputStreamReader(proc.getInputStream()); 
118.  LineNumberReader input = **new** LineNumberReader(ir); 
119.  String line = input.readLine(); 
120. **if** (line == **null** || line.length() < FAULTLENGTH) \{ 
121. **return****null**; 
122.  \} 
123. **int** capidx = line.indexOf("Caption"); 
124. **int** cmdidx = line.indexOf("CommandLine"); 
125. **int** rocidx = line.indexOf("ReadOperationCount"); 
126. **int** umtidx = line.indexOf("UserModeTime"); 
127. **int** kmtidx = line.indexOf("KernelModeTime"); 
128. **int** wocidx = line.indexOf("WriteOperationCount"); 
129. **long** idletime = 0; 
130. **long** kneltime = 0; 
131. **long** usertime = 0; 
132. **while** ((line = input.readLine()) != **null**) \{ 
133. **if** (line.length() < wocidx) \{ 
134. **continue**; 
135.  \} 
136. // 字段出现顺序：Caption,CommandLine,KernelModeTime,ReadOperationCount,
137. // ThreadCount,UserModeTime,WriteOperation
138.  String caption = Bytes.substring(line, capidx, cmdidx - 1) 
139.  .trim(); 
140.  String cmd = Bytes.substring(line, cmdidx, kmtidx - 1).trim(); 
141. **if** (cmd.indexOf("wmic.exe") >= 0) \{ 
142. **continue**; 
143.  \} 
144. // log.info("line="+line);
145. **if** (caption.equals("System Idle Process") 
146.  || caption.equals("System")) \{ 
147.  idletime += Long.valueOf( 
148.  Bytes.substring(line, kmtidx, rocidx - 1).trim()) 
149.  .longValue(); 
150.  idletime += Long.valueOf( 
151.  Bytes.substring(line, umtidx, wocidx - 1).trim()) 
152.  .longValue(); 
153. **continue**; 
154.  \} 
155. 
156.  kneltime += Long.valueOf( 
157.  Bytes.substring(line, kmtidx, rocidx - 1).trim()) 
158.  .longValue(); 
159.  usertime += Long.valueOf( 
160.  Bytes.substring(line, umtidx, wocidx - 1).trim()) 
161.  .longValue(); 
162.  \} 
163.  retn\[0\] = idletime; 
164.  retn\[1\] = kneltime + usertime; 
165. **return** retn; 
166.  \} **catch** (Exception ex) \{ 
167.  ex.printStackTrace(); 
168.  \} **finally** \{ 
169. **try** \{ 
170.  proc.getInputStream().close(); 
171.  \} **catch** (Exception e) \{ 
172.  e.printStackTrace(); 
173.  \} 
174.  \} 
175. **return****null**; 
176.  \} 
177. 
178. /\*\* \*//\*\*
179.  \* 测试方法.
180.  \* @param args
181.  \* @throws Exception
182.  \* @author amg \* Creation date: 2008-4-30 - 下午04:47:29
183.  \*/
184. **public****static****void** main(String\[\] args) **throws** Exception \{ 
185.  IMonitorService service = **new** MonitorServiceImpl(); 
186.  MonitorInfoBean monitorInfo = service.getMonitorInfoBean(); 
187.  System.out.println("cpu占有率=" \+ monitorInfo.getCpuRatio()); 
188. 
189.  System.out.println("可使用内存=" \+ monitorInfo.getTotalMemory()); 
190.  System.out.println("剩余内存=" \+ monitorInfo.getFreeMemory()); 
191.  System.out.println("最大可使用内存=" \+ monitorInfo.getMaxMemory()); 
192. 
193.  System.out.println("操作系统=" \+ monitorInfo.getOsName()); 
194.  System.out.println("总的物理内存=" \+ monitorInfo.getTotalMemorySize() + "kb"); 
195.  System.out.println("剩余的物理内存=" \+ monitorInfo.getFreeMemory() + "kb"); 
196.  System.out.println("已使用的物理内存=" \+ monitorInfo.getUsedMemory() + "kb"); 
197.  System.out.println("线程总数=" \+ monitorInfo.getTotalThread() + "kb"); 
198.  \} 
199. \}

该实现类中需要用到一个自己编写byte的工具类，该类的代码如下所示：

Java代码 ![收藏代码][icon_star.png]

1.  **package** com.amgkaka.performance; 
2.  
3.  /\*\* \*//\*\*
4.   \* byte操作类.
5.   \* @author amg \* @version 1.0 
6.   \* Creation date: 2008-4-30 - 下午04:57:23
7.   \*/
8.  **public****class** Bytes \{ 
9.  /\*\* \*//\*\*
10.  \* 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
11.  \* 包含汉字的字符串时存在隐患，现调整如下：
12.  \* @param src 要截取的字符串
13.  \* @param start\_idx 开始坐标（包括该坐标)
14.  \* @param end\_idx 截止坐标（包括该坐标）
15.  \* @return
16.  \*/
17. **public****static** String substring(String src, **int** start\_idx, **int** end\_idx)\{ 
18. **byte**\[\] b = src.getBytes(); 
19.  String tgt = ""; 
20. **for**(**int** i=start\_idx; i<=end\_idx; i++)\{ 
21.  tgt +=(**char**)b\[i\]; 
22.  \} 
23. **return** tgt; 
24.  \} 
25. \}

[icon_star.png]: /images/20220611/0803717589e44f24a834de9f18f67292.png