用到一个插件hyperic-sigar

1：下载hyperic-sigar后解压，把sigar-amd64-winnt.dll(64位机器，32位用sigar-x86-winnt.dll)放到你本机的jdk\bin、jdk\jre\bin、jre\bin目录下。

2：maven引入hyperic-sigar依赖，这样就可以用了。

     <dependency>  
         <groupId>org.fusesource</groupId>  
         <artifactId>sigar</artifactId>  
         <version>1.6.4</version>  
     </dependency>

3：hyperic-sigar解压后到hyperic-sigar-1.6.4\bindings\java\examples目录下这里面有很多官方提供的例子，可以直接复制到你的工程下运行测试。

---

我用的是websocket+java-timer做的。

public class KeepRunTime extends TimerTask {

 private static Sigar sigar = new Sigar();  

 @Override  
 public void run() {  
     RunTime rt = new RunTime();  
     rt.setMem(mem());  
     rt.setCpus(cpu());

     DataPushService.pushData(JSONObject.toJSONString(new WebMessage(rt, WebMessage.RUNTIME)));  
 }

 // CPU使用率  
 public static TreeSet<Cpu> cpu() {  
     try {  
         TreeSet<Cpu> cpus = new TreeSet<Cpu>();  
         CpuPerc\[\] list = sigar.getCpuPercList();  
         for (int i=1; i<list.length+1; i++) {  
             Cpu cpu = new Cpu();  
             cpu.setNo(i);  
             cpu.setCpuName("CPU-"+i);  
             cpu.setCpuCombined(CpuPerc.format(list\[i-1\].getCombined()));  
             cpus.add(cpu);  
         }  
         return cpus;  
     } catch (SigarException e) {  
         System.err.println("获取CPU使用率异常");  
         e.printStackTrace();  
         return null;  
     }  
 }

 // MEM使用率  
 public static String mem() {  
     try {  
         Mem mem = sigar.getMem();  
         // 内存总量  
         Long memTotal = mem.getTotal() / 1024L;  
         // 当前内存使用量  
         Long memUsed = mem.getUsed() / 1024L;  
         // 使用率  
         Double usePercent = ((memUsed\*1.0)/memTotal)\*100;  
         // 四舍五入  
         return String.format("%.2f", usePercent);  
     } catch (SigarException e) {  
         System.err.println("获取MEM使用率异常");  
         e.printStackTrace();  
         return null;  
     }  
 }

}

public class RunTime {

 // 内存使用率  
 private String mem;  
 // CPU使用率  
 private TreeSet<Cpu> cpus;

 public String getMem() {  
     return mem;  
 }  
 public void setMem(String mem) {  
     this.mem = mem;  
 }  
 public TreeSet<Cpu> getCpus() {  
     return cpus;  
 }  
 public void setCpus(TreeSet<Cpu> cpus) {  
     this.cpus = cpus;  
 }

 @Override  
 public String toString() {  
     return "RunTime \[mem=" + mem + ", cpus=" + cpus + "\]";  
 }

}

public class Cpu implements Comparable{

 private int no;

 private String cpuName;

 private String cpuCombined;

 public int getNo() {  
     return no;  
 }

 public void setNo(int no) {  
     this.no = no;  
 }

 public String getCpuName() {  
     return cpuName;  
 }

 public void setCpuName(String cpuName) {  
     this.cpuName = cpuName;  
 }

 public String getCpuCombined() {  
     return cpuCombined;  
 }

 public void setCpuCombined(String cpuCombined) {  
     this.cpuCombined = cpuCombined;  
 }

 // 正序  
 @Override  
 public int compareTo(Cpu o) {  
     return (this.no - o.no);  
 }

 @Override  
 public String toString() {  
     return "Cpu \[no=" + no + ", cpuName=" + cpuName + ", cpuCombined="  
             + cpuCombined + "\]";  
 }

}

js:

var runtime = function(data) {
$("#mem").html(data.obj.mem + '%');

 var cpus = data.obj.cpus;  
 var html = "<p>";  
 for (var i = 1; i < cpus.length + 1; i++) {  
     html += "<b>" + cpus\[i-1\].cpuName + "：</b>" +  
             "<span class='runtime' id='span-cpu'>"+ cpus\[i-1\].cpuCombined + "</span>";  
     if (i % 2 == 0) {  
         html += "</p><p>";  
     }  
 }  
 $("#cpu").html(html);  

};

效果：

这里面用了websocket，没提出来具体的代码。

下次我写一个基于netty、websocket.io、springmvc、mybatis、h2database、httpclient、fastjson、https的整合，我现在就在写这样一个项目，等写好了做一个简化版的发上来。