java-two threads to take turns printing a number problem

Implement two threads and print out the numbers in turn, as follows:

Bthread---10aThread---9bThread---8aThread---- -3bThread-2aThread-1

Implemented with the lock class in Java:

Package Com.yjq.thread_demo;import Java.util.concurrent.locks.lock;import Java.util.concurrent.locks.reentrantlock;public class Twothreadprinter {private Lock Threadlock = new Reentrantlock (); Private Boolean flag = false;int count = 10; Thread athread = new Thread (new Runnable () {public void run () {while (true) {//Lock threadlock.lock (); try {if (Count < 1 ) {return;} if (flag) {//Athread task System.out.println ("Athread--" + (count--)); flag =!flag;}} catch (Exception e) {//Todo:handle Exception} finally {//release lock Threadlock.unlock ();}}}); Thread bthread = new Thread (new Runnable () {public void run () {while (true) {//Lock threadlock.lock (); try {if (Count < 1 ) {return;} if (!flag) {//Athread task System.out.println ("Bthread-to" + (count--)); flag =!flag;}} catch (Exception e) {//Todo:handle Exception} finally {//release lock Threadlock.unlock ();}}}); public void Starttwothread () {Athread.start (); Bthread.start ();} public static void Main (string[] args) {Twothreadprinter Twothreadprinter = nEW Twothreadprinter (); Twothreadprinter.starttwothread ();}} 

Implemented with synchronized:

Package Com.yjq.thread_demo;public class TwoThreadPrinter2 {Private Object threadlock = new object (); int count = 10; Thread athread = new Thread (new Runnable () {public void run () {while (true) {//Lock synchronized (Threadlock) {if (Count &l T 1) {return;} Athread task System.out.println ("Athread--" + (count--)); Threadlock.notify (); try {threadlock.wait ();} catch (Exception e) {//Todo:handle Exception}}}); Thread bthread = new Thread (new Runnable () {public void run () {while (true) {//Lock synchronized (Threadlock) {if (Count &l T 1) {return;} Athread task System.out.println ("Bthread--" + (count--)); Threadlock.notify (); try {threadlock.wait ();} catch (Exception e) {//Todo:handle Exception}}}});p ublic void Starttwothread () {Athread.start (); Bthread.start ();} public static void Main (string[] args) {Twothreadprinter twothreadprinter = new Twothreadprinter (); Twothreadprinter.starttwothread ();}}

The lock class method is relatively easy to understand, the block before lock () and Unlock () is locked

The Synchronize method uses less flag to flag which thread to print, because the thread lock's notifity () method releases the lock and wakes other threads, and the Wait () method of the lock locks the lock and sleeps the current thread

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

java-two threads to take turns printing a number problem