Vector 和 ArrayList 线程安全比较

原文链接

Vector:线程安全
ArrayList:非线程安全
测试码:

public class Test {
	public static void main(String[] args) {
		TestThread();
	}
	
	public static void TestThread() {
		List<Object> list= new ArrayList<Object>(100000);
		List<Object> list2 = new Vector<Object>();
		int threadCount = 1000;
		CountDownLatch countDownLatch = new CountDownLatch(threadCount);
		for(int i=0;i<threadCount;i++) {
			new Thread(new Runnable() {

				@Override
				public void run() {
					// TODO Auto-generated method stub
					for(int i=0;i<100;i++) {
						list2.add(new Object());	
					}
					
					for(int i=0;i<100;i++) {
						list.add(new Object());			
					}



					countDownLatch.countDown();
				}
				
			}).start();
		}
		try {
			countDownLatch.await();
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
	    }
		System.out.println("ArrayList Size: "+list.size());
		System.out.println("Vector Size: "+list2.size());
		
	}
}

发现:

1.当不设置ArrayList初始大小时,程序运行会抛出异常 Vector则不会有这个问题
2.ArrayList.szie()<100000,vector.size()=100000,说明多线程操作vector比ArrayList更安全,稳定,不会出现少操作现象