join模拟订单
package com.future.demo.future;/**
*
*
* @author Administrator
*
*/
public class NormalThreadTest { public static void main(String[] args) throws Exception {
long start = System.currentTimeMillis();
// 开启购买厨具线程
ShoppingThread shopping = new ShoppingThread();
shopping.start();
shopping.join(); // 保障厨具购买并送货
// 获取到购买厨具
KitchenWare kc = shopping.kc; // 买食材
FoodMaterial fm = new FoodMaterial();
Thread.sleep(2000);
System.out.println("第二步: 食材已经到位");
// 烹饪美食
cooking(kc, fm);
System.out.println("第三步: 美食烹饪完成");
long end = System.currentTimeMillis();
System.out.println("烹饪美食时间为:" + (end - start));
} /**
* 定义网上购物厨具线程
* @author Administrator
*
*/
static class ShoppingThread extends Thread { // 厨具对象引用
private KitchenWare kc; @Override
public void run() {
System.out.println("第一步: 网上下单");
System.out.println("第一步: 等待厨具");
try {
Thread.sleep(5000); // 等待厨具时间
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("第一步: 快递送货");
// 生产厨具
kc = new KitchenWare();
}
} /**
* 厨具类
* @author Administrator
*
*/
static class KitchenWare { } /**
* 食材类
* @author Administrator
*
*/
static class FoodMaterial { } /**
* 定义烹饪食物的方法
* @param kc
* @param fm
*/
static void cooking(KitchenWare kc, FoodMaterial fm) { }
}
异步进行
package com.future.demo.future;import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;/**
* 异步: 同时进行
* 同步: 排队进行
* @author Administrator
*
*/
public class FutureThreadTest { public static void main(String[] args) throws Exception {
long start = System.currentTimeMillis(); Callable<KitchenWare> callable = new Callable<KitchenWare>() {
public KitchenWare call() throws Exception {
System.out.println("第一步: 网上下单");
System.out.println("第一步: 等待厨具");
try {
Thread.sleep(5000); // 等待厨具时间
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("第一步: 快递送货");
return new KitchenWare();
} };
// 包装为异步执行的对象
FutureTask<KitchenWare> task = new FutureTask<>(callable);
new Thread(task).start(); // 买食材
FoodMaterial fm = new FoodMaterial();
Thread.sleep(2000);
System.out.println("第二步: 食材已经到位"); if (!task.isDone()) {
System.out.println("厨具还没有到.....");
}
// 通过阻塞形式获取到异步块执行的结果
KitchenWare kc = task.get(); // 阻塞
// 烹饪美食
cooking(kc, fm);
System.out.println("第三步: 美食烹饪完成");
long end = System.currentTimeMillis();
System.out.println("烹饪美食时间为:" + (end - start));
} /**
* 厨具类
* @author Administrator
*
*/
static class KitchenWare { } /**
* 食材类
* @author Administrator
*
*/
static class FoodMaterial { } /**
* 定义烹饪食物的方法
* @param kc
* @param fm
*/
static void cooking(KitchenWare kc, FoodMaterial fm) { }
}
线程池
ThreadPoolExecutor
package com.future.demo.threadPool;import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;/**
* ThreadPoolExecutor
* int corePoolSize 线程总数 <= 最大线程数
* int maximumPoolSize 最大线程数
* long keepAliveTime 存活时间
* TimeUnit unit 时间单位 (纳秒，毫秒，秒，分钟,....)
* BlockingQueue<Runnable> workQueue 阻塞队列
* @author Administrator
*
*/
public class ThreadPoolExecutorTest {
public static void main(String[] args) {
// 20来源: 最大线程数 + 阻塞数目
ThreadPoolExecutor executor =
new ThreadPoolExecutor(10, 30, 2000, TimeUnit.MILLISECONDS, new ArrayBlockingQueue<>(10)); for ( int i = 0; i < 40; i++) {
executor.execute(new MyRunnable());
System.out.println("线程池中线程数目：" + executor.getPoolSize() + "，队列中等待执行的任务数目：" + executor.getQueue().size()
+ "，任务总数目：" + executor.getTaskCount());
} // 防止线程溢出(执行完成的线程会被及时关闭)
executor.shutdownNow();
} static class MyRunnable implements Runnable {
public void run() {
String threadName = Thread.currentThread().getName();
System.out.println(threadName+ "准备执行......");
/*try {
// jdk1.5 之后官方推荐使用此方法睡眠
TimeUnit.MILLISECONDS.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}*/
System.out.println(threadName+"执行完成......"); }
}
}
SingleThreadExecutor
package com.future.demo.threadPool;import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* 创建一个单线程的线程池。这个线程池只有一个线程在工作，
* 也就是相当于单线程串行执行所有任务。如果这个唯一的线程因为异常结束，
* 那么会有一个新的线程来替代它。此线程池保证所有任务的执行顺序按照任务的提交顺序执行。
* @author Administrator
*
*/
public class SingleThreadExecutorTest { public static void main(String[] args) {
MyThread t1 = new MyThread("AAA");
MyThread t2 = new MyThread("BBB");
MyThread t3 = new MyThread("CCC");
MyThread t4 = new MyThread("DDD"); ExecutorService singleThreadExecutor = Executors.newSingleThreadExecutor();
// 保证在线程池中的线程执行的顺序
singleThreadExecutor.execute(t4);
singleThreadExecutor.execute(t1);
singleThreadExecutor.execute(t2);
singleThreadExecutor.execute(t3); singleThreadExecutor.shutdown();
}}class MyThread extends Thread {
private String name;
public MyThread(String name) {
super(name);
this.name = name;
} @Override
public void run() {
System.out.println(name+"执行");
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
FixedThreadExecutor
package com.future.demo.threadPool;import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* 创建固定大小的线程池。每次提交一个任务就创建一个线程，直到线程达到线程池的最大大小。
* 线程池的大小一旦达到最大值就会保持不变，
* 如果某个线程因为执行异常而结束，那么线程池会补充一个新线程。
* @author Administrator
*
*/
public class FixedThreadExecutorTest { public static void main(String[] args) {
MyThread t1 = new MyThread("AAA");
MyThread t2 = new MyThread("BBB");
MyThread t3 = new MyThread("CCC");
MyThread t4 = new MyThread("DDD"); ExecutorService singleThreadExecutor = Executors.newFixedThreadPool(2); singleThreadExecutor.execute(t1);
singleThreadExecutor.execute(t2);
singleThreadExecutor.execute(t3);
singleThreadExecutor.execute(t4); singleThreadExecutor.shutdown();
}}
CacheThreadExecutor
package com.future.demo.threadPool;import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* 创建一个可缓存的线程池。如果线程池的大小超过了处理任务所需要的线程，
那么就会回收部分空闲（60秒不执行任务）的线程，
当任务数增加时，此线程池又可以智能的添加新线程来处理任务。
此线程池不会对线程池大小做限制，线程池大小完全依赖于操作系统（或者说JVM）能够创建的最大线程大小
* @author Administrator
*
*/
public class CacheThreadExecutorTest { public static void main(String[] args) {
MyThread t1 = new MyThread("AAA");
MyThread t2 = new MyThread("BBB");
MyThread t3 = new MyThread("CCC");
MyThread t4 = new MyThread("DDD"); ExecutorService singleThreadExecutor = Executors.newCachedThreadPool(); singleThreadExecutor.execute(t1);
singleThreadExecutor.execute(t2);
singleThreadExecutor.execute(t3);
singleThreadExecutor.execute(t4); singleThreadExecutor.shutdown();
}}
ScheduledThreadExecutor
package com.future.demo.threadPool;import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;/***
* 创建一个大小无限的线程池。此线程池支持定时以及周期性执行任务的需求。
* @author Administrator
*
*/
public class ScheduledThreadExecutorTest {
public static void main(String[] args) {
ScheduledThreadPoolExecutor exec = new ScheduledThreadPoolExecutor(2); exec.scheduleAtFixedRate(new Runnable() {// 每隔一段时间就触发异常 @Override
public void run() { System.out.println("================"); } }, 1, 1, TimeUnit.SECONDS); exec.scheduleAtFixedRate(new Runnable() {// 每隔一段时间打印系统时间，证明两者是互不影响的 public void run() { System.out.println(System.nanoTime()); } }, 1, 100, TimeUnit.MILLISECONDS); }
}
线程组
ThreadGroup
package com.future.demo.threadgroup;public class ThreadGroupTest {
public static void main(String[] args) throws Exception {
ThreadGroup group = new ThreadGroup("main Thread");
Thread t1 = new Thread(group,"AAA") {
@Override
public void run() {
while(true) {
System.out.println(Thread.currentThread().getName()+"执行");
}
}
};
Thread t2 = new Thread(group,"BBB") {
@Override
public void run() {
while(true) {
System.out.println(Thread.currentThread().getName()+"执行");
}
}
}; t1.start();
t2.start(); Thread.sleep(5000); System.out.println(Thread.currentThread().getThreadGroup().activeCount()); group.list();
}
}
package com.future.demo.conn;import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.locks.ReentrantLock;public class NormalConnectionPool {
private Map<String, Connection> connPool = new HashMap<String, Connection>();
private ReentrantLock lock = new ReentrantLock(); public Connection getConnection(String key) { Connection conn = null; try {
lock.lock(); if (connPool.containsKey(key)) {
conn = connPool.get(key);
} else {
// 创建连接对象
conn = crateConn();
connPool.put(key, conn);
} } catch (Exception e) {
e.printStackTrace();
} finally {
lock.unlock();
} return conn;
} private Connection crateConn() {
return new Connection();
} public static void main(String[] args) throws Exception {
NormalConnectionPool pool = new NormalConnectionPool();
long start = System.currentTimeMillis(); Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
for (int i = 0; i < 200000; i++) {
Connection conn = pool.getConnection("KK");
System.out.println("KK-----"+conn);
}
}
}); Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
for (int i = 0; i < 200000; i++) {
Connection conn = pool.getConnection("YY");
System.out.println("YY-----"+conn);
}
}
}); Thread t3 = new Thread(new Runnable() {
@Override
public void run() {
for (int i = 0; i < 200000; i++) {
Connection conn = pool.getConnection("FF");
System.out.println("FF-----"+conn);
}
}
}); t1.start();t2.start();t3.start();
t1.join();t2.join();t3.join(); long end = System.currentTimeMillis();
System.out.println(end - start);
}
}class Connection {}
package com.future.demo.conn;import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;public class SuperConnectionPool { private ConcurrentHashMap<String, FutureTask<Connection>> connPool = new ConcurrentHashMap<>(); public Connection getConnection(String key) {
Connection conn = null;
FutureTask<Connection> connectionTask = connPool.get(key); if (connectionTask != null) {
try {
conn = connectionTask.get();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
} else {
Callable<Connection> callable = new Callable<Connection>() { @Override
public Connection call() throws Exception {
return new Connection();
} };
FutureTask<Connection> newTask = new FutureTask<>(callable);
connPool.putIfAbsent(key, newTask);
if (connectionTask == null) {
connectionTask = newTask;
connectionTask.run();
}
} try {
conn = connectionTask.get();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
} return conn;
} public static void main(String[] args) throws InterruptedException {
SuperConnectionPool pool = new SuperConnectionPool();
long start = System.currentTimeMillis(); Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
for (int i = 0; i < 200000; i++) {
Connection conn = pool.getConnection("KK");
System.out.println("KK-----"+conn);
}
}
}); Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
for (int i = 0; i < 200000; i++) {
Connection conn = pool.getConnection("YY");
System.out.println("YY-----"+conn);
}
}
}); Thread t3 = new Thread(new Runnable() {
@Override
public void run() {
for (int i = 0; i < 200000; i++) {
Connection conn = pool.getConnection("FF");
System.out.println("FF-----"+conn);
}
}
}); t1.start();t2.start();t3.start();
t1.join();t2.join();t3.join(); long end = System.currentTimeMillis();
System.out.println(end - start);
}
}
