线程安全和非安全用例

1、Sequence类

package self.inter;

public interface Sequence {
	int getNumber();
}

2、SequenceB

package self.inter.impl;

import self.inter.Sequence;
import self.thread.ClientThread;
/**
 * 这个类线程安全
 * 
 * @author xujl
 *
 */
public class SequenceB implements Sequence {
	private static int number = 0;
	
	
	private static ThreadLocal<Integer> numberContainer = new ThreadLocal<Integer>(){
		@Override
		protected Integer initialValue(){
			return 0;
		}
	};
	
	public int getNumber() {
		numberContainer.set(numberContainer.get()+1);
		return numberContainer.get();
	}
	
	public static void main(String[] args) {
		Sequence sequence = new SequenceB();
		ClientThread ct1 = new ClientThread(sequence);
		ClientThread ct2 = new ClientThread(sequence);
		ClientThread ct3 = new ClientThread(sequence);
		ct1.start();
		ct2.start();
		ct3.start();
	}
	
}

3、SequenceA

package self.inter.impl;

import self.inter.Sequence;
import self.thread.ClientThread;
/**
 * 这个类运行一下，是线程非安全
 * 因为线程之间共享的static变量无法保证对于不同线程而言是安全的
 * @author xujl
 *
 * 2017年6月2日
 */
public class SequenceA implements Sequence {
	private static int number = 0;
	
	
	@Override
	public int getNumber() {
		number = number+1;
		return number;
	}
	
	public static void main(String[] args) {
		Sequence sequence = new SequenceA();
		ClientThread ct1 = new ClientThread(sequence);
		ClientThread ct2 = new ClientThread(sequence);
		ClientThread ct3 = new ClientThread(sequence);
		ct1.start();
		ct2.start();
		ct3.start();
	}
	
}