delayprintthread.java

递归子程序法：对应每个非终结符语法单元编一个独立的处理过程（或子程序）。语法分析从读入第一个单词开始

	package twothread;
	/** 
	 * Java语言实验参考程序
	 * Company 北京师范大学计算机系
 
	 * @author 孙一林
	 * @version 1.0
	 */
	class DelayPrintThread extends Thread {
	  private static int threadCount = 0;
	  private int threadNumber = 0;
	  private int delay;
	  public DelayPrintThread() {
		delay = (int)( Math.random() * 5000 );		// 计算休眠时间
		threadCount++;								// 线程计数
		threadNumber = threadCount;					// 线程号
	  }
	  public void run() {
		try {
		  sleep( delay );							// 子线程休眠一段时间：delay
		}
		catch ( InterruptedException e ) {
		}
		System.out.println( "This is Thread# " + threadNumber +
						" with a delay of " + delay + "." );
	  }
	}