创建线程池的7种方式
import java.util.Date;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
public class ThreadPoolCreationTest {
public static void fixedThreadPool(){
// ExecutorService threadPool = Executors.newFixedThreadPool(2);
//
// Runnable runnable = new Runnable(){
// @Override
// public void run(){
// System.out.println("任务被执行，线程：" + Thread.currentThread().getName());
// }
// };
//
// Future<?> submit = threadPool.submit(runnable);
//// System.out.println(submit);
//// System.out.println(submit.isDone());
// threadPool.execute(runnable);
// threadPool.execute(runnable);
// threadPool.execute(runnable);
ExecutorService threadPool = Executors.newFixedThreadPool(2);
for(int i = 0; i < 4; i++){
threadPool.execute(() -> {
System.out.println("任务被执行，线程：" + Thread.currentThread().getName());
});
}
}
public static void cachedThreadPool(){
ExecutorService threadPool = Executors.newCachedThreadPool();
for(int i=0;i<10;i++){
threadPool.execute(() -> {
System.out.println("任务被执行，线程：" + Thread.currentThread().getName());
});
}
}
public static void singleThreadPool(){
ExecutorService threadPool = Executors.newSingleThreadExecutor();
for(int i = 0; i < 10; i++){
threadPool.execute(() -> {
System.out.println("任务被执行，线程：" + Thread.currentThread().getName());
});
}
}
public static void scheduledThreadPool(){
ScheduledExecutorService threadPool = Executors.newScheduledThreadPool(5);
System.out.println("添加任务，时间："+new Date());
threadPool.schedule(()->{
System.out.println("任务被执行，时间："+new Date());
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}, 1, TimeUnit.SECONDS);
}
public static void singleThreadScheduledPool(){
ScheduledExecutorService threadPool = Executors.newSingleThreadScheduledExecutor();
System.out.println("添加任务，时间："+new Date());
threadPool.schedule(()->{
System.out.println("任务被执行，时间："+new Date());
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}, 2, TimeUnit.SECONDS);
}
public static void workStealingPool(){
ExecutorService threadPool = Executors.newWorkStealingPool();
for(int i = 0; i < 10; i++){
final int index = i;
threadPool.execute(() ->{
System.out.println(index + "被执行，线程名"+Thread.currentThread().getName());
});
}
while(!threadPool.isTerminated()){
}
}
//推荐使用
//阿里巴巴开发手册：线程池不允许使用 Executors 去创建，而是通过 ThreadPoolExecutor 的方式，这样的处理方式让写的同学更加明确线程池的运行规则，规避资源耗尽的风险。
public static void myThreadPoolExecutor(){
final int CORE_POOL_SIZE = 5;
final int MAX_POOL_SIZE = 10;
final int QUEUE_CAPACITY = 100;
final Long KEEP_ALIVE_TIME = 1L;
ThreadPoolExecutor threadPool = new ThreadPoolExecutor(
CORE_POOL_SIZE,
MAX_POOL_SIZE,
KEEP_ALIVE_TIME,
TimeUnit.SECONDS,
new ArrayBlockingQueue<>(QUEUE_CAPACITY),
new ThreadPoolExecutor.CallerRunsPolicy()
);
for(int i = 0; i < 10; i++){
final int index = i;
threadPool.execute(() -> {
System.out.println(index+"被执行，线程名："+Thread.currentThread().getName());
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
});
}
}
public static void main(String[] args) {
//fixedThreadPool();
//cachedThreadPool();
//singleThreadPool();
//scheduledThreadPool();
//singleThreadScheduledPool();
//workStealingPool();
myThreadPoolExecutor();
}
}
