java多线程详解三多线程5种实现方式

java种多线程实现方式主要有5种，继承Thread类，实现Runnable接口、实现Callable和 FutureTask包装器来创建Thread线程、使用ExecutorService、Callable、Future实现有返回结果的多线程，使用线程池来实现多线程。

方式一：继承Thread类

public class ThreadTest {
public static void main(String[] args){
for(int i = 0;i<100;i++){
MyThread my = new MyThread();
my.start();
}
}
}
class MyThread extends Thread{
public void run(){
System.out.println(Thread.currentThread().getId());
}
}

方式二：实现Runnable接口

public class ThreadTest {
public static void main(String[] args){

for(int i = 0;i<100;i++){
Thread my = new Thread(new MyThread());
my.start();
}
}
}
class MyThread implements Runnable{
public void run(){
System.out.println(Thread.currentThread().getId());
}
}

方式三：使用FutureTask 和Callable接口的到返回值

Callable<String> callable = new Callable&l
4000
t;String>(){

@Override
public String call() throws Exception {
// TODO Auto-generated method stub
return new Random().nextInt(1000)+"";
}

};
FutureTask<String> future = new FutureTask<String>(callable);
new Thread(future).start();
try {
Thread.sleep(1000);
System.out.println(future.get());
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

方式四：使用Future和Callable接口

ExecutorService threadPool = Executors.newCachedThreadPool();
CompletionService<Integer> cs = new ExecutorCompletionService<Integer>(threadPool);
for(int i = 1; i < 5; i++) {
final int taskID = i;
cs.submit(new Callable<Integer>() {
public Integer call() throws Exception {
return taskID;
}
});
}
// 可能做一些事情
for(int i = 1; i < 5; i++) {
try {
System.out.println(cs.take().get());
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}

方式五：使用线程池创建线程

@Test
public void testSingleThreadPool() {
// 创建单个线程
ExecutorService singleThreadPool = Executors.newSingleThreadExecutor();
singleThreadPool.execute(new Runnable() {

@Override
public void run() {
System.out.println(Thread.currentThread().getId());
}

});
}

@Test
public void testCachedThreadPool() {
// 创建缓冲线程池
ExecutorService cachedThreadPool = Executors.newCachedThreadPool();
for (int i = 0; i < 100; i++)
cachedThreadPool.execute(new Runnable() {
@Override
public void run() {
System.out.println(Thread.currentThread().getId());

}

});
}
@Test
public void testFixedThreadPool(){
//创建5个线程的固定线程池
ExecutorService fixedThreadPool = Executors.newFixedThreadPool(5);
for(int i = 0;i<5;i++ )
fixedThreadPool.execute(new Runnable() {
@Override
public void run() {
System.out.println(Thread.currentThread().getId());

}

});
}
@Test
public void testThreadPool(){
ThreadPoolExecutor pool = new ThreadPoolExecutor(5,8,1,TimeUnit.SECONDS,new ArrayBlockingQueue<Runnable>(100));
//这种式JDK实现线程池的方式
 for(int i=0;i<100;i++)
pool.execute(new Runnable(){

@Override
public void run() {
System.out.println(Thread.currentThread().getId());

}

});
}