被synchronized修饰的方法特别之处

synchronized关键字修饰一个方法，可以保证多线程状态下，该方法的调用对象是同步变化的。如下例所示：两个线程同时调用vector的remove方法对vector变量进行操作，vector的长度是连续变化的。（Vector是线程安全的，Vector类中的方法都被synchronized修饰，当然包括remove()方法）

public class _Main {
	private static Vector<Integer> vector = new Vector<Integer>();


	public static void main(String[] args) {
		while (true) {
			for (int i = 0; i < 10; i++) {
				vector.add(i);
				System.out.println("加入的值：" + vector.get(i));
			}


			Thread remove1Thread = new Thread(new Runnable() {
				@Override
				public void run() {
					for (int i = 0; i < 10; i++) {
						vector.remove(i);
						System.out.println("Thread1:" + vector.size());
					}
				}
			});


			Thread remove2Thread = new Thread(new Runnable() {
				@Override
				public void run() {
					for (int i = 0; i < 10; i++) {
						vector.remove(i);
						System.out.println("Thread2: " + vector.size());
					}
				}
			});


			remove1Thread.start();
			remove2Thread.start();
			while(Thread.activeCount() > 20);
		}
	}
	/**执行后部分结果
	 * Thread1:96
Thread1:95
Thread1:94
Thread1:93
Thread1:92
Thread1:91
Thread1:90
Thread2: 89
Thread2: 88
Thread2: 87
Thread2: 86
Thread2: 85
Thread2: 84
Thread2: 83
Thread2: 82
Thread2: 81
Thread2: 80
Thread1:79
Thread1:78
	 */
}