使用Java代码获取服务器性能信息及局域网内主机名
最近做个项目，就是要取得cpu占有率等等的系统信息，一开始以为要用动态链接库了，但后来发现可以像下面这样做，不去调用jni，这样省去了很多看新技术的时间o(∩_∩)o...
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：
packagecom.amgkaka.performance;
/***//**
*监视信息的JavaBean类.
*@authoramg
*@version1.0
*Creationdate:2008-4-25-上午10:37:00
*/
publicclassMonitorInfoBean{
/***//**可使用内存.*/
privatelongtotalMemory;
/***//**剩余内存.*/
privatelongfreeMemory;
/***//**最大可使用内存.*/
privatelongmaxMemory;
/***//**操作系统.*/
privateStringosName;
/***//**总的物理内存.*/
privatelongtotalMemorySize;
/***//**剩余的物理内存.*/
privatelongfreePhysicalMemorySize;
/***//**已使用的物理内存.*/
privatelongusedMemory;
/***//**线程总数.*/
privateinttotalThread;
/***//**cpu使用率.*/
privatedoublecpuRatio;
publiclonggetFreeMemory(){
returnfreeMemory;
}
publicvoidsetFreeMemory(longfreeMemory){
this.freeMemory=freeMemory;
}
publiclonggetFreePhysicalMemorySize(){
returnfreePhysicalMemorySize;
}
publicvoidsetFreePhysicalMemorySize(longfreePhysicalMemorySize){
this.freePhysicalMemorySize=freePhysicalMemorySize;
}
publiclonggetMaxMemory(){
returnmaxMemory;
}
publicvoidsetMaxMemory(longmaxMemory){
this.maxMemory=maxMemory;
}
publicStringgetOsName(){
returnosName;
}
publicvoidsetOsName(StringosName){
this.osName=osName;
}
publiclonggetTotalMemory(){
returntotalMemory;
}
publicvoidsetTotalMemory(longtotalMemory){
this.totalMemory=totalMemory;
}
publiclonggetTotalMemorySize(){
returntotalMemorySize;
}
publicvoidsetTotalMemorySize(longtotalMemorySize){
this.totalMemorySize=totalMemorySize;
}
publicintgetTotalThread(){
returntotalThread;
}
publicvoidsetTotalThread(inttotalThread){
this.totalThread=totalThread;
}
publiclonggetUsedMemory(){
returnusedMemory;
}
publicvoidsetUsedMemory(longusedMemory){
this.usedMemory=usedMemory;
}
publicdoublegetCpuRatio(){
returncpuRatio;
}
publicvoidsetCpuRatio(doublecpuRatio){
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：
packagecom.amgkaka.performance;
/***//**
*获取系统信息的业务逻辑类接口.
*@authoramg*@version1.0
*Creationdate:2008-3-11-上午10:06:06
*/
publicinterfaceIMonitorService{
/***//**
*获得当前的监控对象.
*@return返回构造好的监控对象
*@throwsException
*@authoramgkaka
*Creationdate:2008-4-25-上午10:45:08
*/
publicMonitorInfoBeangetMonitorInfoBean()throwsException;
}
该类的实现类MonitorServiceImpl如下所示：
packagecom.amgkaka.performance;
importjava.io.InputStreamReader;
importjava.io.LineNumberReader;
importsun.management.ManagementFactory;
importcom.sun.management.OperatingSystemMXBean;
/***//**
*获取系统信息的业务逻辑实现类.
*@authoramg*@version1.0Creationdate:2008-3-11-上午10:06:06
*/
publicclassMonitorServiceImplimplementsIMonitorService{
//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
privatestaticfinalintCPUTIME=5000;
privatestaticfinalintPERCENT=100;
privatestaticfinalintFAULTLENGTH=10;
/***//**
*获得当前的监控对象.
*@return返回构造好的监控对象
*@throwsException
*@authoramg*Creationdate:2008-4-25-上午10:45:08
*/
publicMonitorInfoBeangetMonitorInfoBean()throwsException{
intkb=1024;
//可使用内存
longtotalMemory=Runtime.getRuntime().totalMemory()/kb;
//剩余内存
longfreeMemory=Runtime.getRuntime().freeMemory()/kb;
//最大可使用内存
longmaxMemory=Runtime.getRuntime().maxMemory()/kb;
OperatingSystemMXBeanosmxb=(OperatingSystemMXBean)ManagementFactory
.getOperatingSystemMXBean();
//操作系统
StringosName=System.getProperty("os.name");
//总的物理内存
longtotalMemorySize=osmxb.getTotalPhysicalMemorySize()/kb;
//剩余的物理内存
longfreePhysicalMemorySize=osmxb.getFreePhysicalMemorySize()/kb;
//已使用的物理内存
longusedMemory=(osmxb.getTotalPhysicalMemorySize()-osmxb
.getFreePhysicalMemorySize())
/kb;
//获得线程总数
ThreadGroupparentThread;
for(parentThread=Thread.currentThread().getThreadGroup();parentThread
.getParent()!=null;parentThread=parentThread.getParent())
;
inttotalThread=parentThread.activeCount();
doublecpuRatio=0;
if(osName.toLowerCase().startsWith("windows")){
cpuRatio=this.getCpuRatioForWindows();
}
//构造返回对象
MonitorInfoBeaninfoBean=newMonitorInfoBean();
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);
returninfoBean;
}
/***//**
*获得CPU使用率.
*@return返回cpu使用率
*@authoramg*Creationdate:2008-4-25-下午06:05:11
*/
privatedoublegetCpuRatioForWindows(){
try{
StringprocCmd=System.getenv("windir")
+"\\system32\\wbem\\wmic.exeprocessgetCaption,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){
longidletime=c1[0]-c0[0];
longbusytime=c1[1]-c0[1];
returnDouble.valueOf(
PERCENT*(busytime)/(busytime+idletime))
.doubleValue();
}else{
return0.0;
}
}catch(Exceptionex){
ex.printStackTrace();
return0.0;
}
}
/***//**
*读取CPU信息.
*@paramproc
*@return
*@authoramg*Creationdate:2008-4-25-下午06:10:14
*/
privatelong[]readCpu(finalProcessproc){
long[]retn=newlong[2];
try{
proc.getOutputStream().close();
InputStreamReaderir=newInputStreamReader(proc.getInputStream());
LineNumberReaderinput=newLineNumberReader(ir);
Stringline=input.readLine();
if(line==null||line.length()<FAULTLENGTH){
returnnull;
}
intcapidx=line.indexOf("Caption");
intcmdidx=line.indexOf("CommandLine");
introcidx=line.indexOf("ReadOperationCount");
intumtidx=line.indexOf("UserModeTime");
intkmtidx=line.indexOf("KernelModeTime");
intwocidx=line.indexOf("WriteOperationCount");
longidletime=0;
longkneltime=0;
longusertime=0;
while((line=input.readLine())!=null){
if(line.length()<wocidx){
continue;
}
//字段出现顺序：Caption,CommandLine,KernelModeTime,ReadOperationCount,
//ThreadCount,UserModeTime,WriteOperation
Stringcaption=Bytes.substring(line,capidx,cmdidx-1)
.trim();
Stringcmd=Bytes.substring(line,cmdidx,kmtidx-1).trim();
if(cmd.indexOf("wmic.exe")>=0){
continue;
}
//log.info("line="+line);
if(caption.equals("SystemIdleProcess")
||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;
returnretn;
}catch(Exceptionex){
ex.printStackTrace();
}finally{
try{
proc.getInputStream().close();
}catch(Exceptione){
e.printStackTrace();
}
}
returnnull;
}
/***//**
*测试方法.
*@paramargs
*@throwsException
*@authoramg*Creationdate:2008-4-30-下午04:47:29
*/
publicstaticvoidmain(String[]args)throwsException{
IMonitorServiceservice=newMonitorServiceImpl();
MonitorInfoBeanmonitorInfo=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：
packagecom.amgkaka.performance;
/***//**
*byte操作类.
*@authoramg*@version1.0
*Creationdate:2008-4-30-下午04:57:23
*/
publicclassBytes{
/***//**
*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：
*@paramsrc要截取的字符串
*@paramstart_idx开始坐标（包括该坐标)
*@paramend_idx截止坐标（包括该坐标）
*@return
*/
publicstaticStringsubstring(Stringsrc,intstart_idx,intend_idx){
byte[]b=src.getBytes();
Stringtgt="";
for(inti=start_idx;i<=end_idx;i++){
tgt+=(char)b[i];
}
returntgt;
}
}
运行下MonitorBeanImpl类，读者将会看到当前的内存、cpu利用率等信息。
PS：得到局域网内所有主机名的方法
importjava.net.InetAddress;
importjava.net.UnknownHostException;
publicclassA{
staticpublicvoidmain(String[]args){
try{
//通过主机名称得到IP地址
InetAddressaddress=InetAddress.getByName("192.168.9.148");
System.out.println("192.168.9.148"+":"+address.getHostAddress());
//通过IP得到主机名称
Stringips="192.168.9.",ip;
InetAddressaddip;
for(inti=148;i<255;i++){
ip=ips+i;
addip=InetAddress.getByName(ip);
System.out.println(ip+":"+addip.getHostName());
}
}
catch(UnknownHostExceptionuhe){
System.err.println("Unabletofind:"+"192.168.9.148");
}
}
}