Some Scala code that uses Java APIs present in tools.jar (only JDKs) to programmatically produce a jstack-like thread dump. Useful to debug application and test deadlocks.

RuntimeUtils.scala

object RuntimeUtils {
  def requestThreadDump: String = {
    // Get the PID of the current JVM process
    val selfName = java.lang.management.ManagementFactory.getRuntimeMXBean().getName()
    val selfPid = selfName.substring(0, selfName.indexOf('@'))

    // Attach to the VM
    import com.sun.tools.attach.VirtualMachine
    import sun.tools.attach.HotSpotVirtualMachine;
    val vm = VirtualMachine.attach(selfPid);
    val hotSpotVm = vm.asInstanceOf[HotSpotVirtualMachine];

    // Request a thread dump
    val inputStream = hotSpotVm.remoteDataDump()
    try new String(Stream.continually(inputStream.read).takeWhile(_ != -1).map(_.toByte).toArray)
    finally inputStream.close()
  }
}