static  class solver implements Runnable  {

           static calculator(problem){
                //Some code
                 if(condition)
                {solver s = new solver(newproblem);
                   new Thread(s).start();}
                   }

     Public solver(int newproblem)
     {

           this.problem = newproblem ;
       }
     public void run() {
                // TODO Auto-generated method stub
                calculator(promblem);

            }
}

i am having a big array maze of 100x100 and i am trying to solve it and i am getting an error java.lang.OutOfMemoryError: unable to create new native thread(after running a code for some times). How can solve this , How can i use ExecutorService i think that will solve the problem or i want something like this
If Number of generated threads>4K then stop the first 100 threads