Java的高并发编程系列（六）生产者消费者面试题解析

public class MyContainer1 <T>{
private final LinkedList<T> lists = new LinkedList<>();
private final int MAX = 10; //最多10个元素
private int count = 0;
public synchronized void put(T t){
while (lists.size() == MAX) { //while正常情况下和wait()一起使用，
try {
this.wait(); //effective java
} catch (InterruptedException e) {
e.printStackTrace();
}
}
lists.add(t);
++ count;
this.notifyAll(); //通知消费者线程进行消费
}
public synchronized T get(){
T t = null;
while (lists.size() == 0) {
try {
this.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
t = lists.removeFirst();
count --;
this.notifyAll(); //通知生产者进行生产
return t;
}
public static void main(String[] args) {
MyContainer1<String> c = new MyContainer1<>();
//启动消费者线程
for (int i = 0; i < 100; i++) {
new Thread(()->{
for (int j = 0; j < 5; j++) {
System.out.println(c.get());
}
}, "c" + i).start();
}

try {
TimeUnit.SECONDS.sleep(2);
} catch (InterruptedException e) {
e.printStackTrace();
}
//启动生产者线程
for (int i = 0; i < 2; i++) {
new Thread(()->{
for (int j = 0; j < 25; j++) {
c.put(Thread.currentThread().getName() + "" + j);
}
}, "p" + i).start();
}
}
}

public class MyContainer2<T> {
private final LinkedList<T> lists = new LinkedList<>();
private final int MAX = 10;
private int count = 0;
private Lock lock = new ReentrantLock();
private Condition producer = lock.newCondition();
private Condition consumer = lock.newCondition();

public void put(T t){
try {
lock.lock();
while (lists.size() == MAX) {
producer.await();
}
lists.add(t);
++count;
consumer.signalAll(); //通知消费者线程进行消费
} catch (Exception e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}

public T get(){
T t = null;
try {
lock.lock();
while (lists.size() == 0) {
consumer.await();
}

lists.removeFirst();
count --;
producer.signalAll(); //通知生产者进行生产
} catch (Exception e) {
e.printStackTrace();
} finally {
lock.unlock();
}
return t;
}

public static void main(String[] args) {
MyContainer2<String> c = new MyContainer2<>();
//启消费者线程
for (int i = 0; i < 100; i++) {
new Thread(()->{
for (int j = 0; j < 5; j++) {
System.out.println(c.get());
}
}, "c" + i).start();
}

try {
TimeUnit.SECONDS.sleep(2);
} catch (InterruptedException e) {
e.printStackTrace();
}

//启动生产者线程
for (int i = 0; i < 2; i++) {
new Thread(()->{
for (int j = 0; j < 25; j++) {
c.put(Thread.currentThread().getName() + "" + j);
}
}, "p" + i).start();
}
}
}