public class Main {
static int i = 0;
public static void main(String[] args) {
//启动线程
new mThread().start();
new mThread().start();
//主线程中循环
for (; i < 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
}
}
}
class mThread extends Thread {
int i = 0;
@Override
public void run() {
super.run();
for (; i < 100; i++) {
System.out.println(getName() + "->" + i);
}
}
}
public class Main {
static int i = 0;
public static void main(String[] args) {
//启动线程
mThread mThread = new mThread();
new Thread(mThread).start();
new Thread(mThread).start();
//主线程中循环
for (; i < 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
}
}
}
class mThread implements Runnable {
int i = 0;
@Override
public void run() {
for (; i < 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
}
}
}
注意: 上面代码中的Thread 公用的一个Runnable Target 所以变量i只有一份 打印的时候 两个线程公用的是一个变量i,两个线程 不共用一个线程方法就是 创建两个Runnable Target 这样就会创建两个变量i线程和线程之间就没有联系了
public class Main {
static int i = 0;
public static void main(String[] args) {
//启动线程
new Thread(new mThread()).start();
new Thread(new mThread()).start();
//主线程中循环
for (; i < 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
}
}
}
class mThread implements Runnable {
int i = 0;
@Override
public void run() {
for (; i < 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
}
}
}
public class Main {
public static void main(String[] args) throws InterruptedException, ExecutionException {
Main main = new Main();
// 创建线程,创建带返回值的Callable线程
FutureTask<Integer> task = new FutureTask<>((Callable<Integer>) () -> {
int i = 0;
for (; i < 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
}
return i;
});
// 启动线程
new Thread(task).start();
// 主线程
for (int i = 0; i < 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
}
System.out.println("子线程的返回值为:"+task.get());
}
}
public class Main {
public static void main(String[] args) throws InterruptedException, ExecutionException {
// 创建线程,创建带返回值的Callable线程
FutureTask<Integer> task = new FutureTask<>((Callable<Integer>) () -> {
int i = 0;
for (; i < 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
}
return i;
});
// 创建线程空间
Thread thread = new Thread(task);
// 主线程
for (int i = 0; i < 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
if(i == 20){
//启动线程
thread.start();
//让当前线程等待
thread.join();
}
}
System.out.println("子线程的返回值为:"+task.get());
}
}
public class Main {
public static void main(String[] args) throws InterruptedException {
for(int i = 0;i <=100;i++){
System.out.println(Thread.currentThread().getName() + "->" + i);
if(i==20){
mThread thread = new mThread();
mThread thread1 = new mThread();
thread.start();
thread1.start();
thread.join();
}
}
}
}
class mThread extends Thread {
int i = 0;
@Override
public void run() {
super.run();
for (; i < 100; i++) {
System.out.println(getName() + "->" + i);
}
}
}
小结:如果在主线程中创建两个线程(thread ,thread 1)然后在主线程执行thread的join方法,会让主线程等待thread执行完成后才会获得调度。期间 thread和thread1会共同执行。
public class Main {
public static void main(String[] args) throws InterruptedException {
for(int i = 0;i <=100;i++){
System.out.println(Thread.currentThread().getName() + "->" + i);
if(i == 20){
mThread thread = new mThread();
//设置为守护线程,主线程执行完成后 不需要等待子线程执行完就可以退出虚拟机
thread.setDaemon(true);
thread.start();}}}}
class mThread extends Thread {
int i = 0;
@Override
public void run() {
super.run();
for (; i < 800; i++) {
System.out.println(getName() + "->" + i);}}}
public class Main {
public static void main(String[] args) throws InterruptedException {
for (int i = 0; i <= 100; i++) {
System.out.println(Thread.currentThread().getName() + "->" + i);
if (i == 20) {
mThread thread = new mThread();
thread.start();
}
if(i == 50){
Thread.sleep(5000);
}
}
}
}
class mThread extends Thread {
int i = 0;
@Override
public void run() {
super.run();
for (; i < 1000; i++) {
try {sleep(1);} catch (InterruptedException e) {}
System.out.println(getName() + "->" + i);}}}
public class Main {
public static void main(String[] args) throws InterruptedException {
mThread thread = new mThread();
mThread thread1 = new mThread();
thread.setPriority(Thread.MAX_PRIORITY);
thread1.setPriority(Thread.MIN_PRIORITY);
thread.start();
thread1.start();
}
}
class mThread extends Thread {
int i = 0;
@Override
public void run() {
super.run();
for (; i < 100; i++) {
try {
sleep(1);
} catch (InterruptedException e) {
}
System.out.println(getName() + "->" + i);
// 线程让步
if (i == 20) {
yield();
}
}
}
}
先看代码
public class Main {
public static void main(String[] args) throws InterruptedException {
mThread thread = new mThread();
mThread thread1 = new mThread();
mThread thread2 = new mThread();
mThread thread3 = new mThread();
thread.start();
thread1.start();
thread2.start();
thread3.start();
}
}
class mThread extends Thread {
static int i = 100;
@Override
public void run() {
super.run();
try {
sleep(10);
} catch (InterruptedException e) {
}
for (; i > 0;--i) {
System.out.println(getName() + "->" + i);
}
}
}
上面代码正常来说只会出现一个100 可是大多数会出现多个100,这显然是不是我们想要的。
public class Main {
public static void main(String[] args) throws InterruptedException {
new mThread().start();
new mThread().start();
new mThread().start();
new mThread().start();
new mThread().start();
new mThread().start();
new mThread().start();
new mThread().start();
new mThread().start();
new mThread().start();
new mThread().start();
}
}
class mThread extends Thread {
static Integer i = 1000;
@Override
public void run() {
super.run();
try {
sleep(10);
} catch (InterruptedException e) {
}
synchronized(java.util.Calendar.getInstance()){
for (; i > 0;--i) {
System.out.println(getName() + "->" + i);
}
}
}
}
同步方法: