private static final ExecutorService threadPool= Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 2);
 
 public void method(String str) {
	......
	if ([退出循环的条件]) {
	     threadPool.execute(() -> {
	         method(str)
	     });
	 } else {
	     return;
	 }
}