public ThreadGroupRenderer() 
{

}

 public String doRender(Object o) 
{
    if(o instanceof ThreadGroup) {
      StringBuffer sbuf = new StringBuffer();
      ThreadGroup tg = (ThreadGroup) o;
      sbuf.append("java.lang.ThreadGroup[name=");
      sbuf.append(tg.getName());
      sbuf.append(", maxpri=");
      sbuf.append(tg.getMaxPriority());
      sbuf.append("]");
      Thread[] t = new Thread[tg.activeCount()];
      tg.enumerate(t);
      for(int i = 0; i <  t.length; i++) {
	sbuf.append(Layout.LINE_SEP);	
	sbuf.append("   Thread=[");
	sbuf.append(t[i].getName());
	sbuf.append(",");
	sbuf.append(t[i].getPriority());
	sbuf.append(",");
	sbuf.append(t[i].isDaemon());
	sbuf.append("]");
      }
      return sbuf.toString();
    } else {
      // this is the best we can do
      return o.toString();
    }
}

Render a ThreadGroup object similar to the way that the ThreadGroup#list method output information.

The output of a simple program consisting of one main thread is:

java.lang.ThreadGroup[name=main, maxpri=10]
Thread=[main,5,false]

The boolean value in thread information is the value returned by Thread#isDaemon .