java获得CPU、系统内存情况
JXM：Monitoring and Management Interface for the Java? Platform
通过jmx可以监控vm内存使用,系统内存使用等
以下是网上某博客代码，特点是通过window和linux命令获得CPU使用率。
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/** * @author yans * @date 2011-10-6 下午11:23:45 * @description */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;}}?之后，建立bean的接口
/** * @author yans * @date 2011-10-6 下午11:24:31 * @description */public interface IMonitorService {public MonitorInfoBean getMonitorInfoBean() throws Exception;}?然后，就是最关键的，得到cpu的利用率，已用内存，可用内存，最大内存等信息。
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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.lang.management.ManagementFactory;import java.util.StringTokenizer;import com.sun.management.OperatingSystemMXBean;/** * @author yans * @date 2011-10-6 下午11:24:58 * @description 获取系统信息的业务逻辑实现类. */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 final File versionFile = new File("/proc/version");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 yans */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 * @author yans */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 yans */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,WriteOperationString 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 * @author yans */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");}}?
其中，Bytes类用来处理字符串
/** * @author yans * @date 2011-10-6 下午11:26:01 * @description */public 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;}}?
1 楼 qiuxianxiang 2011-10-09 LZ,我实在想不通您为什么要写Bytes这个类。这个类的作用不是和String里的SubString方法差不多么。但是感觉效率上可能比不上SubString这个方法的。这不是多此一举？ 2 楼 qiuxianxiang 2011-10-09 另：赞美楼主，这正是我想要的！ 3 楼 xiaoboss 2011-10-10 bytes 的方法单独拎出来了，开始没有想太多，呵呵