생활코딩 자바 리뉴얼 5. 실습 영상으로 자바 파악하기

https://www.youtube.com/watch?v=bZuoyW26zW4&list=PLuHgQVnccGMAIluRRVsC1e79ri-dwnBmR&index=11 

 

• 데스크톱 앱

import javax.swing.*;   
import java.awt.Dimension;
import java.awt.Toolkit;
public class HelloWorldGUIApp{
    public static void main(String[] args){
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new JFrame("HelloWorld GUI");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setPreferredSize(new Dimension(800, 300));
                JLabel label = new JLabel("Hello World!!", SwingConstants.RIGHT);
                frame.getContentPane().add(label);
                Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
                frame.setLocation(dim.width/2-400/2, dim.height/2-300/2);

                frame.pack();
                frame.setVisible(true);
            }
        });
    }
}

 

• IOT 전구로 모스부호 표현 

 

import com.pi4j.io.gpio.GpioController;
import com.pi4j.io.gpio.GpioFactory;
import com.pi4j.io.gpio.GpioPinDigitalOutput;
import com.pi4j.io.gpio.PinState;
import com.pi4j.io.gpio.RaspiPin;

public class HelloWorldRaspberryPi {

public static void main(String[] args) throws InterruptedException {

final GpioController gpio = GpioFactory.getInstance();
final GpioPinDigitalOutput pin = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_01, "PinLED", PinState.LOW);
final int SHORT_INTERVAL = 200;
final int LONG_INTERVAL = SHORT_INTERVAL * 3;
final int LETTER_INTERVAL = SHORT_INTERVAL * 7;

while (true) {
// H
pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(SHORT_INTERVAL);
pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(SHORT_INTERVAL);
pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(SHORT_INTERVAL);
pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(LETTER_INTERVAL);

// e
pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(LETTER_INTERVAL);

// l
pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(SHORT_INTERVAL);

pin.high();
Thread.sleep(LONG_INTERVAL);
pin.low();
Thread.sleep(SHORT_INTERVAL);

pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(SHORT_INTERVAL);
pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(LONG_INTERVAL);

// l
pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(SHORT_INTERVAL);

pin.high();
Thread.sleep(LONG_INTERVAL);
pin.low();
Thread.sleep(SHORT_INTERVAL);

pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(SHORT_INTERVAL);
pin.high();
Thread.sleep(SHORT_INTERVAL);
pin.low();
Thread.sleep(LONG_INTERVAL);
}
}
}

 

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
GpioController cannot be resolved to a type
GpioFactory cannot be resolved
GpioPinDigitalOutput cannot be resolved to a type
RaspiPin cannot be resolved to a variable
PinState cannot be resolved to a variable

at HelloWorldRaspberryPi.main(HelloWorldRaspberryPi.java:11)

 

하 저번영상 부터 계속 불러오기 하는데 에러가 뜬다.... 뭐지 ant 관련돼서 오류도 있다 ㅎ 난 일단 자바 불러오기 하는 법 부터 배워야겠다.. new project new file 헷갈림

 

 

• 안드로이드 스튜디오 통한 모바일앱

 

package com.example.myjavaworld;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);   =>아래 xml 디자인 파일 실행
    }
}

 

------activity_main.xml---------------

 

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>