Java编程多线程之共享数据代码详解

package com.iot.thread;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
/**
 * Created by brian on 2016/2/4.
 */
public class ThreadScopeShareData {
	//准备一个哈希表，为每个线程准备数据
	private static Map<Thread,Integer> threadData = new HashMap<>();
	public static void main(String[] args) {
		for (int i=0;i<2;i++){
			new Thread(
			          new Runnable() {
				@Override
				        public void run() {
					int data = new Random().nextint();
					threadData.put(Thread.currentThread(),data);
					System.out.println(Thread.currentThread()+" put data："+data);
					new A().get();
					new B().get();
				}
			}
			).start();
		}
	}
	static class A{
		public void get(){
			int data = threadData.get(Thread.currentThread());
			System.out.println("A from "+Thread.currentThread()+" get data "+data);
		}
	}
	static class B{
		public void get(){
			int data = threadData.get(Thread.currentThread());
			System.out.println("B from "+Thread.currentThread()+" get data "+data);
		}
	}
}

package com.iot.thread;
import java.util.Random;
/**
 * Created by brian on 2016/2/4.
 */
public class ThreadLocalTest {
	private static ThreadLocal<Integer> threadInger = new ThreadLocal<>();
	public static void main(String[] args) {
		for (int i=0;i<2;i++){
			new Thread(new Runnable() {
				@Override
				        public void run() {
					int data = new Random().nextint(100);
					threadInger.set(data);
					System.out.println(Thread.currentThread()+" put data："+data);
					MyThreadScopeData.getThreadInstance().setName(Thread.currentThread().toString());
					MyThreadScopeData.getThreadInstance().setAge(data%10);
					new A().get();
					new B().get();
				}
			}
			).start();
		}
	}
	static class A{
		public void get(){
			int data = threadInger.get();
			System.out.println("A from "+Thread.currentThread()+" get data "+data);
			MyThreadScopeData myThreadScopeData = MyThreadScopeData.getThreadInstance();
			System.out.println("A from "+myThreadScopeData);
		}
	}
	static class B{
		public void get(){
			int data = threadInger.get();
			System.out.println("B from "+Thread.currentThread()+" get data "+data);
			MyThreadScopeData myThreadScopeData = MyThreadScopeData.getThreadInstance();
			System.out.println("B from "+myThreadScopeData);
		}
	}
}
/**
 * 将多变量封装起来的数据类
 * 单例模式，内置ThreadLocal类型变量
 */
class MyThreadScopeData{
	private MyThreadScopeData(){
	}
	private static ThreadLocal<MyThreadScopeData> data = new ThreadLocal<>();
	public static MyThreadScopeData getThreadInstance(){
		MyThreadScopeData instance = data.get();
		if(instance == null){
			instance = new MyThreadScopeData();
			data.set(instance);
		}
		return instance;
	}
	private String name;
	private int age;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	@Override
	  public String toString() {
		String reVal = super.toString()+"-{name,age}"+":{"+getName()+","+getAge()+"}";
		return reVal;
	}
}

package com.iot.thread;
/**
 * Created by brian on 2016/2/4.
 */
public class MutiThreadShareData {
	private static MutiShareData mutiShareData = new MutiShareData();
	public static void main(String[] args) {
		for (int i=0;i<3;i++){
			new Thread(
			          new Runnable() {
				@Override
				            public void run() {
					System.out.println(Thread.currentThread()+":{j from "+ mutiShareData.getJ()+" + to: "+mutiShareData.increment()+"}");
				}
			}
			).start();
		}
		for (int i=0;i<2;i++){
			new Thread(
			          new Runnable() {
				@Override
				            public void run() {
					System.out.println(Thread.currentThread()+":{j from "+ mutiShareData.getJ()+" - to: "+mutiShareData.decrement()+"}");
				}
			}
			).start();
		}
	}
}
/**
 * 将共享数据封装在另一对象中（操作数据的方法也在该对象完成）
 */
class MutiShareData{
	private int j = 0;
	public synchronized int increment(){
		return ++j;
	}
	public synchronized int decrement(){
		return --j;
	}
	public synchronized int getJ() {
		return j;
	}
	public synchronized void setJ(int j) {
		this.j = j;
	}
}