[JAVA] Thread-1 (Thread, Runnable)

Thread

동작하고 있는 프로그램을 Process라고 함.
보통은 한 개의 Process가 하나의 업무을 처리하고 종료하지만 Thread를 이용하면 하나의 Process에서 여러개의 업무를 동시(병렬)에 처리 할 수 있다.

1. Thread 상속

ThreadExam01.java

public class ThreadExam01 extends Thread {
	int seq;
	
	public ThreadExam01(int seq){
		this.seq = seq;
	}
	
	@Override
	public void run() {
		System.out.println(this.seq + " thread START");
		
		try{
			Thread.sleep(2000);
		}catch(Exception ex){
			ex.printStackTrace();
		}
		
		System.out.println(this.seq + " thread END");
	}
}

ThreadMain01.java

public class ThreadMain01 {

	public static void main(String[] args) {
		try{
			for(int i=0; i<10; i++){
				Thread thread = new ThreadExam01(i);
				thread.start();
			}
		}catch(Exception ex){
			ex.printStackTrace();
		}			
		
		System.out.println("ThreadMain01 END...");
	}
}

결과

0 thread START
3 thread START
2 thread START
1 thread START
5 thread START
4 thread START
6 thread START
ThreadMain01 END...
7 thread START
9 thread START
8 thread START
4 thread END
8 thread END
7 thread END
9 thread END
2 thread END
3 thread END
6 thread END
1 thread END
5 thread END
0 thread END

2. Runnable 인터페이스 구현

ThreadExam02.java

public class ThreadExam02 implements Runnable {
	int seq;
	
	public ThreadExam02(int seq) {
		this.seq = seq;
	}
	
	@Override
	public void run() {
		System.out.println(this.seq + " thread START");
		
		try{
			Thread.sleep(2000);
		}catch(Exception ex){
			ex.printStackTrace();
		}
		
		System.out.println(this.seq + " thread END");
	}
}

ThreadMain02.java

public class ThreadMain02 {

	public static void main(String[] args) {
		try{
			
			for(int i=0; i<10; i++){
				Thread thread = new Thread(new ThreadExam02(i));
				thread.start();
			}
			
			System.out.println("ThreadMain02 END");
		}catch(Exception ex){
			ex.printStackTrace();
		}
	}
}

결과

0 thread START
4 thread START
2 thread START
1 thread START
5 thread START
3 thread START
ThreadMain02 END
7 thread START
6 thread START
9 thread START
8 thread START
4 thread END
1 thread END
2 thread END
0 thread END
5 thread END
7 thread END
6 thread END
3 thread END
9 thread END
8 thread END