[Java] Thread 예제

package Thread;

class ThreadDemo extends Thread{ //실제 작업, 스레드를 상속받아서 스레드가 된다.

//private String name;

// public ThreadDemo(String name) {

// this.name = name;

// super(name);

// }

@Override

public void run() { // 자식 스레드가 해야할 일을 적어주는 곳

int sum = 0;

for(int i=0; i<5; i++) {

try {

sleep(500); //오버라이드 규칙으로 인해 throws말고 try/catch를 사용해야함

//시분할 작업, 프로그램 속도 제어

} catch (InterruptedException e) {

e.printStackTrace();

}

sum += i;

System.out.println(getName()+":"+sum);

}

} 

}

public class ThreadTest1 {

public static void main(String[] args) { //메인스레드

//ThreadDemo demo1 = new ThreadDemo("first"); 

  // 위에서 스레드를 상속받았으니 인스턴스가 스레드가 된다.

 //ThreadDemo demo2 = new ThreadDemo("second"); // 자식스레드

ThreadDemo demo1 = new ThreadDemo(); 

ThreadDemo demo2 = new ThreadDemo(); 

demo1.start();

demo2.start();

}

}

---

package Thread;

class ThreadDemo1 implements Runnable{

@Override

public void run() { //call back 메소드, Thread만 호출 가능

int sum = 0;

for(int i=0; i<5; i++) { 

try {

Thread.sleep(500); //document로 찾았을때 static은 인스턴스 없이 사용가능

} catch (InterruptedException e) {

e.printStackTrace();

}

sum += i;

System.out.println(Thread.currentThread().getName()+":"+sum);

}

}

}

public class ThreadTest2 {

public static void main(String[] args) {

ThreadDemo1 demo1 = new ThreadDemo1();

ThreadDemo1 demo2 = new ThreadDemo1();

Thread t1 = new Thread(demo1); //인터페이스인 Runnable->Thread로 포장

Thread t2 = new Thread(demo2);

t1.start();

t2.start();

}

}

---

package Thread;

class ThreadDemo2 extends Thread{

String name;

public ThreadDemo2(String name) {

super(name);

}

@Override

public void run() {

System.out.println(getName()+"자식 스레드 시작");

int cnt = 0;

do {

try {

sleep(200);

} catch (InterruptedException e) {

e.printStackTrace();

}

cnt++;

System.out.println(getName()+":"+cnt);

}while(cnt<10);

System.out.println("자식 스레드 종료");

}

}

public class ThreadTest3 {

public static void main(String[] args) {

System.out.println("메인 스레드 시작");

ThreadDemo2 demo1 = new ThreadDemo2("first");

ThreadDemo2 demo2 = new ThreadDemo2("second");

demo1.start();

demo2.start();

int cnt = 0;

do {

try {

Thread.sleep(200);

}catch(InterruptedException e) {

e.printStackTrace();

}

cnt++;

System.out.println(".");

}while(cnt<10);

System.out.println("메인 스레드 종료");

}

}

---

package Thread;

//ThreadTest3을  Thread -> Runnable로 바꾸기

class ThreadDemo3 implements Runnable{

String name;

ThreadDemo3(String name){

this.name = name;

}

@Override

public void run() {

System.out.println(name+"자식 스레드 시작");

int cnt = 0;

do {

try {

Thread.sleep(200);

} catch (InterruptedException e) {

e.printStackTrace();

}

cnt++;

System.out.println(name+":"+cnt);

}while(cnt<10);

System.out.println("자식 스레드 종료");

}

}

public class ThreadTest4{

public static void main(String[] args) {

System.out.println("메인 스레드 시작");

ThreadDemo2 demo1 = new ThreadDemo2("first");

ThreadDemo2 demo2 = new ThreadDemo2("second");

Thread t1 = new Thread(demo1);

Thread t2 = new Thread(demo2);

t1.start();

t2.start();

int cnt = 0;

do {

try {

Thread.sleep(200);

}catch(InterruptedException e) {

e.printStackTrace();

}

cnt++;

System.out.println(".");

}while(cnt<10);

System.out.println("메인 스레드 종료");

}

}

---

package Thread;

class ThreadDemo4 implements Runnable{

String name;

// Thread t;

ThreadDemo4(String n){

name=n;

// t = new Thread(this);

// t.start();

new Thread(this).start();

}

@Override

public void run() {

for(int i=0; i<5;i++) {

System.out.println(name+":"+i);

}

}

}

public class ThreadTest5 {

public static void main(String[] args) {

ThreadDemo4 d1 = new ThreadDemo4("스레드1");

ThreadDemo4 d2 = new ThreadDemo4("스레드2");

ThreadDemo4 d3 = new ThreadDemo4("스레드3");

}

}

---

<Syncronized 예제>

package Thread;

class Toilet{

public synchronized static void openDoor(String name) {

System.out.println(name + "입장");

for(int i=0; i<100000; i++) {

if(i == 5000) {

System.out.println(name+"끄응~~~!!");

}

}

System.out.println(name+"퇴장");

}

}

 class Family extends Thread{

Toilet toilet;

String who;

Family(Toilet t, String w){

toilet = t;

who = w;

}

@Override

public void run() {

toilet.openDoor(who);

}

}

public class SyncTest1 {

public static void main(String[] args) {

Toilet t = new Toilet();

Family father = new Family(t, "아버지");

Family mother = new Family(t, "어머니");

Family brother = new Family(t, "형");

Family sister = new Family(t, "누나");

Family me = new Family(t, "나");

mother.start();

brother.start();

sister.start();

me.start();

}

}

---

package Thread;

import java.util.Stack;

//자판기 예제

class AutoMachine{ //자판기

Stack store = new Stack();  // Stack -> 넣을때는 : Push() 꺼내올때는 : POP()

synchronized void putDrink(String drink) {

store.push(drink);

notify(); //wait()로 쉬게한 Thread를 실행시키는 메소드

}

synchronized String getDrink() {

while(store.isEmpty()) //저장소가 비어있는 동안 기다리기

try {

wait();

} catch (InterruptedException e) {

e.printStackTrace();

}

return store.pop().toString();

}

}

class Producer implements Runnable{ //공급자

private AutoMachine auto;

Producer(AutoMachine a){

auto=a;

}

@Override

public void run() {

for(int i=0; i<10; i++) {

System.out.println(Thread.currentThread().getName()+": 음료수 No."+ i + "채워 넣음");

auto.putDrink("음료수 No."+i);

try {

Thread.sleep(100);

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}

}

class Consumer implements Runnable{ //고객

private AutoMachine auto;

Consumer(AutoMachine a){

auto = a;

}

@Override

public void run() {

for(int i=0;i<10;i++) {

System.out.println(Thread.currentThread().getName()+auto.getDrink()+"꺼내 먹음");

try {

Thread.sleep(500);

} catch (InterruptedException e) {

e.printStackTrace();

}

  }

   }

}

public class SyncTest2 {

public static void main(String[] args) {

AutoMachine auto = new AutoMachine();

Producer hong = new Producer(auto);

Consumer kim = new Consumer(auto);

Thread h = new Thread(hong, "홍길동");

Thread k = new Thread(kim, "김유신");

h.start();

k.start();

}

}