| Java中多线程涉及下面4点
创建单线程：继承Tread类 和 实现Rannable接口；
多线程使用：手动实例化多个线程 或者 使用线程池 ExecutorService；
多线程共享数据同步：可以采用同步synchronized执行run方法中的操作；
合理使用多线程同步数据，防止死锁问题。
1.创建线程
继承Tread类- public class MyThread extends Thread {
-
- public void run() {
- System.out.println(Thread.currentThread().getName());
- }
-
- public static void main(String[] args) {
- //不能共享数据
- //MyThread myThread = new MyThread();
- //能共享数据
- Thread myThread = new Thread(new MyThread());
- myThread.start();
- }
- }
实现Rannable接口 - public class MyThread implements Runnable {
-
- public void run() {
- System.out.println(Thread.currentThread().getName());
- }
-
- public static void main(String[] args) {
- //能共享数据
- Thread myThread = new Thread(new MyThread());
- myThread.start();
- }
- }
- public class MyThread implements Runnable {
-
- public void run() {
- System.out.println(Thread.currentThread().getName());
- }
-
- public static void main(String[] args) {
- MyThread myThread = new MyThread();
- new Thread(myThread).start();
- new Thread(myThread).start();
- new Thread(myThread).start();
- }
- }
使用线程池 ExecutorService - public class MyThread implements Runnable {
-
- public void run() {
- System.out.println(Thread.currentThread().getName());
- }
-
- public static void main(String[] args) {
- ExecutorService pool = Executors.newCachedThreadPool();
- MyThread myThread = new MyThread();
- for(int i = 0; i < 3; i++){
- pool.execute(myThread);
- }
- //关闭线程池
- pool.shutdown();
- }
- }
- import java.util.concurrent.ExecutorService;
- import java.util.concurrent.Executors;
- public class MyThread implements Runnable {
- private int tickets = 100;
- private synchronized void sale() {
- if (tickets > 0) {
- System.out.println(Thread.currentThread().getName() + " 剩余："
- + (--tickets) + "张票");
- try {
- Thread.sleep(100);
- } catch (InterruptedException e) {
- e.printStackTrace();
- }
- } else{
- Thread.currentThread().stop();
- }
- }
- public void run() {
- while(true){
- sale();
- }
- }
- public static void main(String[] args) {
- ExecutorService pool = Executors.newCachedThreadPool();
- MyThread myThread = new MyThread();
- for (int i = 0; i < 3; i++) {
- pool.execute(myThread);
- }
- pool.shutdown();
- }
- }
4.死锁
当线程之间互相等待共享资源时，会产生死锁问题。我们可以在多线程的程序中减少同步关键字的使用，减少每一次占用资源的时间之类的措施来降低死锁出现的可能性。
来自： http://my.oschina.net/chenhao901007/blog/476377 | 
