要求：3个线程，分别输出A、B、C。循环10次，给出三种方法，code如下
wait、notify
public class PrintABC {
static int state = 0;
private static Object o = new Object();
public static void main(String[] args) {
ExecutorService ser = Executors.newCachedThreadPool();
ser.submit(new ThreadA());
ser.submit(new ThreadB());
ser.submit(new ThreadC());
ser.shutdown();
}
public static class ThreadA implements Runnable {
@Override
public void run() {
for(int i=0;i<10;i++){
synchronized (o) {
while(state%3!=0){
try {
o.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println("A");
state++;
o.notifyAll();
}
}
}
}
public static class ThreadB implements Runnable {
@Override
public void run() {
for(int i=0;i<10;i++){
synchronized (o) {
while(state%3!=1){
try {
o.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println("B");
state++;
o.notifyAll();
}
}
}
}
public static class ThreadC implements Runnable {
@Override
public void run() {
for(int i=0;i<10;i++){
synchronized (o) {
while(state%3!=2){
try {
o.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println("C");
state++;
o.notifyAll();
}
}
}
}
}
lock、unlock
public class PrintABC2 {
static int state = 0;
private static Lock lock = new ReentrantLock();
public static void main(String[] args) {
ExecutorService ser = Executors.newCachedThreadPool();
ser.submit(new ThreadA());
ser.submit(new ThreadB());
ser.submit(new ThreadC());
ser.shutdown();
}
public static class ThreadA implements Runnable {
@Override
public void run() {
for(int i=0;i<10;){
lock.lock();
if(state%3==0){
System.out.println("A");
state++;
i++;
}
lock.unlock();
}
}
}
public static class ThreadB implements Runnable {
@Override
public void run() {
for(int i=0;i<10;){
lock.lock();
if(state%3==1){
System.out.println("B");
state++;
i++;
}
lock.unlock();
}
}
}
public static class ThreadC implements Runnable {
@Override
public void run() {
for(int i=0;i<10;){
lock.lock();
if(state%3==2){
System.out.println("C");
state++;
i++;
}
lock.unlock();
}
}
}
}
信号量
public class PrintABC3 {
static int state = 0;
private static Semaphore A = new Semaphore(1);
private static Semaphore B = new Semaphore(1);
private static Semaphore C = new Semaphore(1);
public static void main(String[] args) {
ExecutorService ser = Executors.newCachedThreadPool();
try {
B.acquire();
C.acquire();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ser.submit(new ThreadA());
ser.submit(new ThreadB());
ser.submit(new ThreadC());
ser.shutdown();
}
static class ThreadA extends Thread {
@Override
public void run() {
try {
for (int i = 0; i < 10; i++) {
A.acquire();
System.out.print("A");
sleep(2000);
B.release();
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
static class ThreadB extends Thread {
@Override
public void run() {
try {
for (int i = 0; i < 10; i++) {
B.acquire();
System.out.print("B");
C.release();
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
static class ThreadC extends Thread {
@Override
public void run() {
try {
for (int i = 0; i < 10; i++) {
C.acquire();
System.out.print("C");
A.release();
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
结果如下：
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
