20201104_28 thread

#스레드 사용 방법

Thread

-상속

Runnable

-람다

-구현체는 thread생성자에 넘기는 방법

 

• 스레드클래스

package java;

import java.awt.Toolkit;

public class BeepThread extends Thread {

	@Override
	public void run() {
		Toolkit tk = Toolkit.getDefaultToolkit();
		
		while(true) {
			tk.beep();
			try {
				System.out.printf("[%s] thread is running\n ", Thread.currentThread().getName());
				Thread.sleep(5000);
			} catch (InterruptedException e) {
				// TODO: handle exception
				e.printStackTrace();
			}
		}
	}

}

• Application

package java;

import java.util.Scanner;

public class Application {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		final BeepThread thread = new BeepThread();
		thread.start();
		
		Scanner in = new Scanner(System.in);
		while(true) {
			int valueFromKeyboard = in.nextInt();
			System.out.println("main " + valueFromKeyboard);
		}
	}

}

 

#기존실행흐름

main ----->블로킹

 

 

#스레드 실행흐름

main ----->블로킹

thread --------------->

 

#웹서버 스레드(씽글)

main -----> 접속대기 --->접속(socket) --->응답해줌 --->접속대기

 

 

 

 

 

• runnable

import java.io.*;
import java.net.Socket;

public class RequestHandler implements Runnable {

    private Socket client;

    public RequestHandler(Socket client) {
        this.client = client;
    }

    @Override
    public void run() {
        System.out.println("사용자가 들어왔음.");
        try (
                InputStream in = client.getInputStream();
                OutputStream out = client.getOutputStream();
        ) {
            final BufferedReader br = new BufferedReader(new InputStreamReader(in));
            final DataOutputStream dos = new DataOutputStream(out);
            String readLine;
            while (!(readLine = br.readLine()).equals("")) {
                System.out.println(readLine);
            }
            System.out.println("v");
            final byte[] bytes = "message".getBytes();
            response200Header(dos, bytes.length);
            responseBody(dos, bytes);
            Thread.sleep(10000);
            System.out.println(Thread.currentThread().getName() + " 뭔가 다하고 끝냄");
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }

    private void response200Header(DataOutputStream dos, int lengthOfBodyContent) {
        try {
            dos.writeBytes("HTTP/1.1 200 OK \r\n");
            dos.writeBytes("Content-Type: text/html;charset=utf-8\r\n");
            dos.writeBytes("Content-Length: " + lengthOfBodyContent + "\r\n");
            dos.writeBytes("\r\n");
        } catch (IOException e) {
        }
    }

    private void responseBody(DataOutputStream dos, byte[] body) {
        try {
            dos.write(body, 0, body.length);
            dos.flush();
        } catch (IOException e) {
        }
    }
}

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class Application {

    public static void main(String[] args) {
        try (ServerSocket serverSocket = new ServerSocket(1905)) {
            Socket client;
            System.out.println("while 바깥");
            while ((client = serverSocket.accept()) != null) {
                System.out.println("사용자 옴");
                final RequestHandler handler = new RequestHandler(client);  // runnable
                final Thread thread = new Thread(handler);
                thread.start();
                System.out.println("스레드에게 위임");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


}

 

 

 

 

#InputStream

 

-int read(byte[] buf)

파마리터 : 읽을 값을 저장하는 공간

반환값 : 읽은 바이트 수

void close() : 자원 반납 및 입력 스트림 종류(필수)

 

#OutputStream(프로그램이출발지)

-void write(byte[byte[] buf])

파라미터 : 출력 스트림으로 buf를 보냄

-void flush();

-void close() : 자원 반납 및 츨력스트림 종류(필수)

 

 

2.문자기반 스트림

Reader(입력, 도착지)

-int read(char[] cbuf)

파라미터 : cbuf에 문자열을 담음

반환: 읽은 문자개수

Writer(출력, 출발지)

-void write(char[] cbuf)

파라미터 : cbuf에 있는 내용을 출력으로 보냄

void write(String str)

파라미터 : 출력으로 보낼 문자열

flush()

close()

 

 

 

 

• RequestHandlingTask

import java.io.*;
import java.net.Socket;

public class RequestHandlingTask implements Runnable {

    private final Socket socket;

    public RequestHandlingTask(Socket socket) {
        this.socket = socket;
    }

    @Override
    public void run() {
        try (
                final InputStream in = socket.getInputStream();     // from client
                final OutputStream out = socket.getOutputStream();  // to client
        ) {
            // input
            final BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String readLine;
            while (!(readLine = br.readLine()).equals("")) {
                System.out.println(readLine);
            }

            // output
            final String body = "한국말도 돼요?";
            final byte[] raw = body.getBytes();
            final DataOutputStream dos = new DataOutputStream(out);
            // 헤더 쓰는 부분
            dos.writeBytes("HTTP/1.1 200 OK \r\n");
            dos.writeBytes("Content-Type: text/html;charset=utf-8\r\n");
            dos.writeBytes("Content-Length: " + raw.length + "\r\n");
            dos.writeBytes("\r\n");
            // 바디 쓰는 부분
            dos.write(raw, 0, raw.length);
            dos.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}