public static void dumpThreads(ThreadGroup threadGroup, String indent) {
Thread[] threadList = new Thread[threadGroup.activeCount()];
threadGroup.enumerate(threadList);
for (int i = 0; i < threadList.length; i++) {
Thread t = threadList[i];
if (t != null) {
out(
indent
.concat("active thread = ")
.concat(t.toString())
.concat(", daemon = ")
.concat(String.valueOf(t.isDaemon())));
}
}
if (threadGroup.getParent() != null) {
dumpThreads(threadGroup.getParent(), indent + "\t");
}
}
private static void showThreads(PrintStream pw, ThreadGroup g, Thread current) {
int nthreads = g.activeCount();
pw.println("\nThread Group = " + g.getName() + " activeCount= " + nthreads);
Thread[] tarray = new Thread[nthreads];
int n = g.enumerate(tarray, false);
for (int i = 0; i < n; i++) {
Thread thread = tarray[i];
ClassLoader loader = thread.getContextClassLoader();
String loaderName = (loader == null) ? "Default" : loader.getClass().getName();
Thread.State state = thread.getState();
long id = thread.getId();
pw.print(" " + id + " " + thread.getName() + " " + state + " " + loaderName);
if (thread == current) pw.println(" **** CURRENT ***");
else pw.println();
}
int ngroups = g.activeGroupCount();
ThreadGroup[] garray = new ThreadGroup[ngroups];
int ng = g.enumerate(garray, false);
for (int i = 0; i < ng; i++) {
ThreadGroup nested = garray[i];
showThreads(pw, nested, current);
}
}
public static void killAWTThreads(ThreadGroup threadGroup) {
Thread[] threadList = new Thread[threadGroup.activeCount()];
threadGroup.enumerate(threadList);
for (int i = 0; i < threadList.length; i++) {
Thread t = threadList[i];
if (t != null) {
String name = t.getName();
if (name.startsWith("AWT")) {
out("Interrupting thread '".concat(t.toString()).concat("'"));
t.interrupt();
}
}
}
if (threadGroup.getParent() != null) {
killAWTThreads(threadGroup.getParent());
}
}
public static void main(String[] args) throws Exception{
//free和use和total均为KB
long free=0;
long use=0;
long total=0;
int kb=1024;
Runtime rt=Runtime.getRuntime();
total=rt.totalMemory();
free=rt.freeMemory();
use=total-free;
System.out.println("系统内存已用的空间为："+use/kb+" MB");
System.out.println("系统内存的空闲空间为："+free/kb+" MB");
System.out.println("系统总内存空间为："+total/kb+" MB");
OperatingSystemMXBean osmxb = (OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();
long physicalFree=osmxb.getFreePhysicalMemorySize()/kb;
long physicalTotal=osmxb.getTotalPhysicalMemorySize()/kb;
long physicalUse=physicalTotal-physicalFree;
String os=System.getProperty("os.name");
System.out.println("操作系统的版本："+os);
System.out.println("系统物理内存已用的空间为："+physicalFree+" MB");
System.out.println("系统物理内存的空闲空间为："+physicalUse+" MB");
System.out.println("总物理内存："+physicalTotal+" MB");
// 获得线程总数
ThreadGroup parentThread;
for (parentThread = Thread.currentThread().getThreadGroup(); parentThread.getParent() != null; parentThread = parentThread.getParent())
;
int totalThread = parentThread.activeCount();
System.out.println("获得线程总数:"+totalThread);
}
/**
* Returns an array containing the existing client connections. This can be used by concrete
* subclasses to implement messages that do something with each connection (e.g. kill it, send a
* message to it etc.). Remember that after this array is obtained, some clients in this migth
* disconnect. New clients can also connect, these later will not appear in the array.
*
* @return an array of <code>Thread</code> containing <code>ConnectionToClient</code> instances.
*/
public final synchronized Thread[] getClientConnections() {
Thread[] clientThreadList = new Thread[clientThreadGroup.activeCount()];
clientThreadGroup.enumerate(clientThreadList);
return clientThreadList;
}
private Runner getRunner() {
try {
return (Runner) threadpool.pop();
} catch (EmptyStackException empty) {
if (runners.activeCount() > 255) throw new RuntimeException("System overload");
return new Runner();
}
}
public static void main(String args[]) {
try {
ServerSocket serv = new ServerSocket(8080);
System.out.println("showserver created at port 8080.");
ThreadGroup workers = new ThreadGroup("WebWorkers");
while (true) {
if (workers.activeCount() < maxCon) {
System.out.println("Hay " + workers.activeCount() + " hebras corriendo.");
Socket conn = serv.accept();
Thread hs = new Thread(workers, new HebraServ(conn));
hs.start();
} else {
try {
Thread.sleep(500);
} catch (Exception ex) {
}
}
}
} catch (IOException e) {
System.err.println(e);
}
}
private static void dumptg(ThreadGroup tg, PrintWriter out, int indent) {
for (int o = 0; o < indent; o++) out.print("\t");
out.println("G: \"" + tg.getName() + "\"");
Thread[] ths = new Thread[tg.activeCount() * 2];
ThreadGroup[] tgs = new ThreadGroup[tg.activeGroupCount() * 2];
int nt = tg.enumerate(ths, false);
int ng = tg.enumerate(tgs, false);
for (int i = 0; i < nt; i++) {
Thread ct = ths[i];
for (int o = 0; o < indent + 1; o++) out.print("\t");
out.println("T: \"" + ct.getName() + "\"");
}
for (int i = 0; i < ng; i++) {
ThreadGroup cg = tgs[i];
dumptg(cg, out, indent + 1);
}
}
public static boolean kill() {
int j = 0;
Thread meMySelfI = Thread.currentThread();
do {
/* iter across the thread group, killing all members. */
shutdown = true;
Thread list[] = new Thread[tg.activeCount()];
// get all members of the group (including submembers)
int i = tg.enumerate(list);
// no members means that we have gracefully suceeded
if (i == 0) return true;
// if some of the threads do IO during the shut down they will
// need time to accomplish the IO. So, I give it to 'em
// after the first attempt.
if (j > 0)
try {
meMySelfI.sleep(500);
} catch (Exception e) {
}
;
// try to shudown each thread in the group
while (i-- > 0) {
FlickrFtpd tftp = (FlickrFtpd) list[i];
tftp.interrupt(); // first, do it politely
meMySelfI.yield(); // give 'em time to respond
tftp.forceClose(); // second, use a big hammer
meMySelfI.yield(); // give 'em time to respond
}
} while (j++ <= 3);
return false;
}
/**
* Counts the number of clients currently connected.
*
* @return the number of clients currently connected.
*/
public final int getNumberOfClients() {
return clientThreadGroup.activeCount();
}