如何控制Java中的线程，总结了3种方法...

问题：利用Java多线程，轮流打印数字，也就是怎么控制线程....

1：通过synchronized的关键字，对类的static final 成员进行Lock，锁住对象，来实现同步。

private int id;
private static int n = 0;
private static final ThreadTest lock = new ThreadTest();

public ThreadTest(int id) {
this.id = id;
}
public ThreadTest () {

}
@Override
public void run() {
while (n < 100) {
synchronized (lock) {
while ((n % 5 == 0) && (n / 5) % 5 != id) {
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
if (n < 100) {
System.out.print("Thread-" + (id+1) + " : " + " " + (n + 1)
+ " " + (n + 2) + " " + (n + 3) + " " + (n + 4)
+ " " + (n + 5) + "\n");
n += 5;
}
lock.notifyAll();
}
}
}

2.通过AtomicInteger对象，和ExecutorService实现线程之间的同步

private AtomicInteger atomicInteger=new AtomicInteger(0);
private static final int max=20;

class Thread1 implements Runnable{
private int mark=0;
public Thread1(int i){
this.mark=i;
}
public void run() {
while(atomicInteger.get()<max){
if(atomicInteger.get()%5==mark){
System.out.println("线程Thread"+(mark+1)+"打印："+(atomicInteger.get()*5+1)+" "
+(atomicInteger.get()*5+2)+" "+(atomicInteger.get()*5+3)+" "
+(atomicInteger.get()*5+4)+" "+(atomicInteger.get()*5+5));
atomicInteger.getAndIncrement();
}
}
}
}

3.通过ReentrantLock对象和Condition对象实现线程之间的同步

private  int state = 1;
private  int n = 1;
private ReentrantLock lock=new ReentrantLock();
private Condition condition1=lock.newCondition();
private Condition condition2=lock.newCondition();
private Condition condition3=lock.newCondition();
@Override
public void run(){
new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
for (int i = 0; i < 5; i++) {
try {
lock.lock();
while(state!=1)
try{
condition1.await();
}
catch (InterruptedException e) {
// TODO: handle exception
e.printStackTrace();
}
System.out.print(Thread.currentThread().getName()+": ");
for (int j = 0; j < 5; j++) {
System.out.print(n+++" ");
}
System.out.println();
state=2;
condition2.signal();
} finally{
lock.unlock();
}
}
}
},"线程1").start();

new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
for (int i = 0; i < 5; i++) {
try{
lock.lock();
while(state!=2)
try {
condition2.await();
} catch (InterruptedException e) {
// TODO: handle exception
e.printStackTrace();
}
System.out.print(Thread.currentThread().getName()+": ");
for (int j = 0; j < 5; j++) {
System.out.print(n+++" ");
}
System.out.println();
state=3;
condition3.signal();
}
finally{
lock.unlock();
}
}
}
},"线程2").start();

new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
for (int i = 0; i < 5; i++) {
try{
lock.lock();
while(state!=3)
try {
condition3.await();
} catch (InterruptedException e) {
// TODO: handle exception
e.printStackTrace();
}
System.out.print(Thread.currentThread().getName()+": ");
for (int j = 0; j < 5; j++) {
System.out.print(n+++" ");
}
System.out.println();
state=1;
condition1.signal();
}finally{
lock.unlock();
}
}
}
},"线程3").start();
}