자바 – 페이지 4 – Lecture Note

05번째 프로그램(생성자 Constructor)

S005_ContactsConstruct 소스 코드 : 생성자 사용 예 추가

package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S005_ContactsConstruct {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Member p = new Member();
		p.Input();

		Member q = new Member();
		q.Input();

		Member r = new Member("홍길동");
		Member s = new Member("길동이", "010-1111-1111");
		Member t = new Member("길동삼", "010-2222-2222", 5);

		System.out.println("입력된 인원수 : " + Member.cnt);
		p.Print();
		q.Print();
		r.Print();
		s.Print();
		t.Print();
	}

}

class Member{
	static final String univ = "Jeonju Univ.";
	static int cnt = 0;
	String name;
	String phone;
	int speed_dial;

	public Member() {							// 1
		cnt++;
	}

	public Member(String name) { 				// 2
		this();
		this.name = name;
	}

	//매개변수 (String phone)과 위의 (String name)과 구분이 안되기에 오류
/*	public Member(String phone) {
		this();
		this.phone = phone;
	}*/

	public Member(String name, String phone) {	// 3
		this(name);
		this.phone = phone;
	}


	public Member(String name, String phone, int speed_dial) { // 4
		this.name = name;
		this.phone = phone;
		this.speed_dial = speed_dial;
	}

	public void Input() {
		Scanner scan = new Scanner(System.in);

		System.out.print("이름 : ");
		this.name = scan.next();

		System.out.print("휴대폰 : ");
		this.phone = scan.next();
	}

	public void Print() {
		System.out.println(
				"학교 : " + this.univ
				+ " 이름 : " + this.name
				+ " 휴대폰 : " + this.phone
				);
	}
}

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package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S005_ContactsConstruct {

public static void main(String[] args) {

// TODO Auto-generated method stub

Member p = new Member();

p.Input();

Member q = new Member();

q.Input();

Member r = new Member("홍길동");

Member s = new Member("길동이", "010-1111-1111");

Member t = new Member("길동삼", "010-2222-2222", 5);

System.out.println("입력된 인원수 : " + Member.cnt);

p.Print();

q.Print();

r.Print();

s.Print();

t.Print();

}

class Member{

static final String univ = "Jeonju Univ.";

static int cnt = 0;

String name;

String phone;

int speed_dial;

public Member() { // 1

cnt++;

}

public Member(String name) { // 2

this();

this.name = name;

}

//매개변수 (String phone)과 위의 (String name)과 구분이 안되기에 오류

/* public Member(String phone) {

this();

this.phone = phone;

}*/

public Member(String name, String phone) { // 3

this(name);

this.phone = phone;

}

public Member(String name, String phone, int speed_dial) { // 4

this.name = name;

this.phone = phone;

this.speed_dial = speed_dial;

}

public void Input() {

Scanner scan = new Scanner(System.in);

System.out.print("이름 : ");

this.name = scan.next();

System.out.print("휴대폰 : ");

this.phone = scan.next();

}

public void Print() {

System.out.println(

"학교 : " + this.univ

+ " 이름 : " + this.name

+ " 휴대폰 : " + this.phone

);

}

04번째 프로그램(static과 final)

S004_ContactsStaticFinal 소스 코드 : static과 final의 사용 예 추가

package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S004_ContactsStaticFinal {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Student p = new Student();
		p.Input();

		Student q = new Student();
		q.Input();

		System.out.println("입력된 인원수 : " + Student.cnt);
		p.Print();
		q.Print();
	}

}

class Student{
	static final String univ = "Jeonju Univ.";
	static int cnt = 0;
	String name;
	String phone;
	int speed_dial;

	public Student() {
		cnt++;
	}

	public void Input() {
		Scanner scan = new Scanner(System.in);

		System.out.print("이름 : ");
		this.name = scan.next();

		System.out.print("휴대폰 : ");
		this.phone = scan.next();
	}

	public void Print() {
		System.out.println(
				"학교 : " + this.univ
				+ " 이름 : " + this.name
				+ " 휴대폰 : " + this.phone
				);
	}
}

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package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S004_ContactsStaticFinal {

public static void main(String[] args) {

// TODO Auto-generated method stub

Student p = new Student();

p.Input();

Student q = new Student();

q.Input();

System.out.println("입력된 인원수 : " + Student.cnt);

p.Print();

q.Print();

}

class Student{

static final String univ = "Jeonju Univ.";

static int cnt = 0;

String name;

String phone;

int speed_dial;

public Student() {

cnt++;

}

public void Input() {

Scanner scan = new Scanner(System.in);

System.out.print("이름 : ");

this.name = scan.next();

System.out.print("휴대폰 : ");

this.phone = scan.next();

}

public void Print() {

System.out.println(

"학교 : " + this.univ

+ " 이름 : " + this.name

+ " 휴대폰 : " + this.phone

);

}

03번째 프로그램(Class 개념)

스마트폰의 연락처(전화번호부)에 저장된 정보는 무엇이 있나? 이름(name) : String 휴대폰(phone) : 단축번호(speed_dial) : . . S003_Contacts 소스 코드 : 위 연락처 정보를 활용한 코드(Class 사용 없음)

package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S003_Contacts {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan = new Scanner(System.in);

		System.out.print("이름 : ");
		String name = scan.next();

		System.out.print("휴대폰 : ");
		String phone = scan.next();

		//...

		System.out.println(
				"이름 : " + name
				+ " 휴대폰 : " + phone
				);
	}

}

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package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S003_Contacts {

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner scan = new Scanner(System.in);

System.out.print("이름 : ");

String name = scan.next();

System.out.print("휴대폰 : ");

String phone = scan.next();

//...

System.out.println(

"이름 : " + name

+ " 휴대폰 : " + phone

);

}

S003_ContactsClass1 소스 코드 : S003_Contacts를 Class 사용 코드로 변환1

package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S003_ContactsClass1 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan = new Scanner(System.in);
		Person p = new Person();

		System.out.print("이름 : ");
		p.name = scan.next();

		System.out.print("휴대폰 : ");
		p.phone = scan.next();

		//...

		System.out.println(
				"이름 : " + p.name
				+ " 휴대폰 : " + p.phone
				);

	}

}

class Person{
	String name;
	String phone;
	int speed_dial;
}

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package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S003_ContactsClass1 {

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner scan = new Scanner(System.in);

Person p = new Person();

System.out.print("이름 : ");

p.name = scan.next();

System.out.print("휴대폰 : ");

p.phone = scan.next();

//...

System.out.println(

"이름 : " + p.name

+ " 휴대폰 : " + p.phone

);

}

class Person{

String name;

String phone;

int speed_dial;

}

S003_ContactsClass2 소스 코드 : S003_Contacts를 Class 사용 코드로 변환2

package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S003_ContactsClass2 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Friend p = new Friend();

		p.Input();
		p.Print();
	}

}

class Friend{
	String name;
	String phone;
	int speed_dial;

	public void Input() {
		Scanner scan = new Scanner(System.in);

		System.out.print("이름 : ");
		this.name = scan.next();

		System.out.print("휴대폰 : ");
		this.phone = scan.next();
	}

	public void Print() {
		System.out.println(
				"이름 : " + this.name
				+ " 휴대폰 : " + this.phone
				);
	}
}

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package kr.ac.jj.java201812345;

import java.util.Scanner;

public class S003_ContactsClass2 {

public static void main(String[] args) {

// TODO Auto-generated method stub

Friend p = new Friend();

p.Input();

p.Print();

}

class Friend{

String name;

String phone;

int speed_dial;

public void Input() {

Scanner scan = new Scanner(System.in);

System.out.print("이름 : ");

this.name = scan.next();

System.out.print("휴대폰 : ");

this.phone = scan.next();

}

public void Print() {

System.out.println(

"이름 : " + this.name

+ " 휴대폰 : " + this.phone

);

}

위 S003_ContactsClass2 소스 코드에 도서 목록(Book)… Continue Reading 03번째 프로그램(Class 개념)

글꼴 크기 변경 Window – Preferences General – Appearance – Colors and Fonts Java – Java Editor Text Font – Edit Debug – Console font – Edit File – New – Java Project Project Name : Java201812345 (201812345를 본인 학번으로) src 에서 마우스 오른쪽 버튼 – New – Class Package… Continue Reading 02번째 프로그램(Scanner)

자바에서 SQLite 데이터베이스 사용하기

DB Browser for Sqlite 다운로드 : https://sqlitebrowser.org/ DB 생성 및 테이블 생성 DB 명 : D:\address.db Table 명 : taddr Field 5개 과정 JDBC 드라이버 설치 sqlite-jdbc 다운로드 : 링크 다운로드 후 압축해지 1회만 더이상 연결안됨 : https://bitbucket.org/xerial/sqlite-jdbc/downloads/ OpenJDK 사용시 sqlite-jdbc-XXX.jar 파일을 아무 위치로든 옮긴다. 이클립스 -> Project -> Properties -> Java… Continue Reading 자바에서 SQLite 데이터베이스 사용하기

우분투(ubuntu) 리눅스에 자바개발환경 설치

자바 설치 여부 확인 sudo apt-get update java -version

whan@HappyLinux:~/c$ java -version

Command 'java' not found, but can be installed with:

sudo apt install default-jre
sudo apt install openjdk-11-jre-headless
sudo apt install openjdk-8-jre-headless

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whan@HappyLinux:~/c$ java -version

Command 'java' not found, but can be installed with:

sudo apt install default-jre

sudo apt install openjdk-11-jre-headless

sudo apt install openjdk-8-jre-headless

OpenJDK 제거 sudo apt-get purge openjdk* apt-get 이용 설치 Repository에 자바 추가 sudo add-apt-repository ppa:webupd8team/java 자바 설치 sudo apt-get install oracle-java8-installer : Java 8 설치 sudo apt-get install oracle-java7-installer : Java 7 설치 sudo apt-get install oracle-java6-installer : Java 6… Continue Reading 우분투(ubuntu) 리눅스에 자바개발환경 설치

스윙 콤포넌트 추가 방법 1 : 기본 콤포넌트

추가사항 2019-05-09 : JTable 콤포넌트 추가 방법 JFrame을 상속받아 MainUI 클래스 만들기

public class MainUI extends JFrame{
	public MainUI(){
		this.setTitle("201712345 홍길동");
		this.setSize(120, 200);
		this.setLayout(null);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		// 콤포넌트 추가는 이곳에

		this.setVisible(true);
	}

	public static void main(String[] args) {
		new MainUI();
	}
}

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public class MainUI extends JFrame{

public MainUI(){

this.setTitle("201712345 홍길동");

this.setSize(120, 200);

this.setLayout(null);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

// 콤포넌트 추가는 이곳에

this.setVisible(true);

}

public static void main(String[] args) {

new MainUI();

}

콤포넌트 예제 JButton 콤포넌트 1개 추가하기

public class MainUI extends JFrame{
	public MainUI(){
		this.setTitle("201712345 홍길동");
		this.setSize(120, 200);
		this.setLayout(null);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		JButton btnAddr = new JButton("주소록");
		btnAddr.setBounds(10, 10, 100, 25);
		this.add(btnAddr);

		this.setVisible(true);
	}
}

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public class MainUI extends JFrame{

public MainUI(){

this.setTitle("201712345 홍길동");

this.setSize(120, 200);

this.setLayout(null);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JButton btnAddr = new JButton("주소록");

btnAddr.setBounds(10, 10, 100, 25);

this.add(btnAddr);

this.setVisible(true);

}

JButton에 ActionListener 추가하기 #1 : 버튼에 ActionListener 추가하기 1) btnAddr.addActionListener(new Ac 까지 입력하고 Ctrl+Spacebar를 클릭하여 추가

public class MainUI extends JFrame{
	public MainUI(){
		this.setTitle("201712345 홍길동");
		this.setSize(120, 200);
		this.setLayout(null);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		JButton btnAddr = new JButton("주소록");
		btnAddr.setBounds(10, 10, 100, 25);
		this.add(btnAddr);
		btnAddr.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				//new AddressUI();
			}
		});

		this.setVisible(true);
	}
}

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public class MainUI extends JFrame{

public MainUI(){

this.setTitle("201712345 홍길동");

this.setSize(120, 200);

this.setLayout(null);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JButton btnAddr = new JButton("주소록");

btnAddr.setBounds(10, 10, 100, 25);

this.add(btnAddr);

btnAddr.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

//new AddressUI();

}

});

this.setVisible(true);

}

JButton에 ActionListener 추가하기 #2 : MainUI에 ActionListener 인터페이스 추가하기 1) JFrame 뒤에 implements ActionListener를… Continue Reading 스윙 콤포넌트 추가 방법 1 : 기본 콤포넌트

Eclipse의 기능 설명

글꼴 크기 설정 Windows -> Preferences 메뉴 선택 General -> Appearance -> Colors and Fonts 선택 Java -> Java Editor Text Font 를 선택하고 Edit 버튼 클릭하여 글꼴 설정 이클립스의 F3 키의 기능 JDK에서 제공되는 클래스(예 : JFrame) 선택 후 F3을 누르면 JFrame클래스의 소스 코드가 보임 다음 그림과 같이 소스코드가… Continue Reading Eclipse의 기능 설명

자바 GUI 스윙(Swing) 예제

JFrame을 생성하여 사용

public class BasicOperand1 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		JFrame f = new JFrame();
		f.setTitle("연산자");
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		f.setSize(300, 600);

		f.setLayout(null);

		JTextField txtNum1 = new JTextField(20);
		txtNum1.setBounds(10, 10, 200, 25);
		f.add(txtNum1);

		JTextField txtNum2 = new JTextField(20);
		txtNum2.setBounds(10, 50, 200, 25);
		f.add(txtNum2);

		JLabel lblResult = new JLabel("결과출력");
		lblResult.setBounds(10, 90, 200, 25);
		f.add(lblResult);

		JButton btnAdd = new JButton("더하기");
		btnAdd.setBounds(10, 130, 200, 25);
		f.add(btnAdd);
		btnAdd.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				double n1 = Double.parseDouble(txtNum1.getText().toString());
				double n2 = Double.parseDouble(txtNum2.getText().toString());
				double n = n1 + n2;
				lblResult.setText(n + "");
			}
		});


		f.setVisible(true);
	}
}

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public class BasicOperand1 {

public static void main(String[] args) {

// TODO Auto-generated method stub

JFrame f = new JFrame();

f.setTitle("연산자");

f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

f.setSize(300, 600);

f.setLayout(null);

JTextField txtNum1 = new JTextField(20);

txtNum1.setBounds(10, 10, 200, 25);

f.add(txtNum1);

JTextField txtNum2 = new JTextField(20);

txtNum2.setBounds(10, 50, 200, 25);

f.add(txtNum2);

JLabel lblResult = new JLabel("결과출력");

lblResult.setBounds(10, 90, 200, 25);

f.add(lblResult);

JButton btnAdd = new JButton("더하기");

btnAdd.setBounds(10, 130, 200, 25);

f.add(btnAdd);

btnAdd.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

double n1 = Double.parseDouble(txtNum1.getText().toString());

double n2 = Double.parseDouble(txtNum2.getText().toString());

double n = n1 + n2;

lblResult.setText(n + "");

}

});

f.setVisible(true);

}

JFrame을 상속받아 사용

public class BasicOperand2 extends JFrame {

	public BasicOperand2() {
		this.setTitle("연산자");
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setSize(300, 600);

		this.setLayout(null);

		JTextField txtNum1 = new JTextField(20);
		txtNum1.setBounds(10, 10, 200, 25);
		this.add(txtNum1);

		JTextField txtNum2 = new JTextField(20);
		txtNum2.setBounds(10, 50, 200, 25);
		this.add(txtNum2);

		JLabel lblResult = new JLabel("결과출력");
		lblResult.setBounds(10, 90, 200, 25);
		this.add(lblResult);

		JButton btnAdd = new JButton("더하기");
		btnAdd.setBounds(10, 130, 200, 25);
		this.add(btnAdd);
		btnAdd.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				double n1 = Double.parseDouble(txtNum1.getText().toString());
				double n2 = Double.parseDouble(txtNum2.getText().toString());
				double n = n1 + n2;
				lblResult.setText(n + "");
			}
		});

		this.setVisible(true);
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		new BasicOperand2();
	}
}

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public class BasicOperand2 extends JFrame {

public BasicOperand2() {

this.setTitle("연산자");

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.setSize(300, 600);

this.setLayout(null);

JTextField txtNum1 = new JTextField(20);

txtNum1.setBounds(10, 10, 200, 25);

this.add(txtNum1);

JTextField txtNum2 = new JTextField(20);

txtNum2.setBounds(10, 50, 200, 25);

this.add(txtNum2);

JLabel lblResult = new JLabel("결과출력");

lblResult.setBounds(10, 90, 200, 25);

this.add(lblResult);

JButton btnAdd = new JButton("더하기");

btnAdd.setBounds(10, 130, 200, 25);

this.add(btnAdd);

btnAdd.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

double n1 = Double.parseDouble(txtNum1.getText().toString());

double n2 = Double.parseDouble(txtNum2.getText().toString());

double n = n1 + n2;

lblResult.setText(n + "");

}

});

this.setVisible(true);

}

public static void main(String[] args) {

// TODO Auto-generated method stub

new BasicOperand2();

}

ActionListener를 별도로 만들어 사용

public class BasicOperand3 extends JFrame {
	JTextField txtNum1;
	JTextField txtNum2;
	JLabel lblResult;

	ActionListener actionListener = new ActionListener() {

		@Override
		public void actionPerformed(ActionEvent e) {
			// TODO Auto-generated method stub

			double n1 = Double.parseDouble(txtNum1.getText().toString());
			double n2 = Double.parseDouble(txtNum2.getText().toString());
			double n = 0;

			System.out.println(e.getActionCommand());
			switch(e.getActionCommand()) {
			case "더하기" :
				n = n1 + n2;
				break;
			}
			lblResult.setText(n + "");

		}
	};

	public BasicOperand3() {
		this.setTitle("연산자");
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setSize(300, 600);

		this.setLayout(null);

		txtNum1 = new JTextField(20);
		txtNum1.setBounds(10, 10, 200, 25);
		this.add(txtNum1);

		txtNum2 = new JTextField(20);
		txtNum2.setBounds(10, 50, 200, 25);
		this.add(txtNum2);

		lblResult = new JLabel("결과출력");
		lblResult.setBounds(10, 90, 200, 25);
		this.add(lblResult);

		JButton btnAdd = new JButton("더하기");
		btnAdd.setBounds(10, 130, 200, 25);
		this.add(btnAdd);
		btnAdd.addActionListener(actionListener);

		this.setVisible(true);
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		new BasicOperand3();
	}
}

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public class BasicOperand3 extends JFrame {

JTextField txtNum1;

JTextField txtNum2;

JLabel lblResult;

ActionListener actionListener = new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

double n1 = Double.parseDouble(txtNum1.getText().toString());

double n2 = Double.parseDouble(txtNum2.getText().toString());

double n = 0;

System.out.println(e.getActionCommand());

switch(e.getActionCommand()) {

case "더하기" :

n = n1 + n2;

break;

}

lblResult.setText(n + "");

}

};

public BasicOperand3() {

this.setTitle("연산자");

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.setSize(300, 600);

this.setLayout(null);

txtNum1 = new JTextField(20);

txtNum1.setBounds(10, 10, 200, 25);

this.add(txtNum1);

txtNum2 = new JTextField(20);

txtNum2.setBounds(10, 50, 200, 25);

this.add(txtNum2);

lblResult = new JLabel("결과출력");

lblResult.setBounds(10, 90, 200, 25);

this.add(lblResult);

JButton btnAdd = new JButton("더하기");

btnAdd.setBounds(10, 130, 200, 25);

this.add(btnAdd);

btnAdd.addActionListener(actionListener);

this.setVisible(true);

}

public static void main(String[] args) {

// TODO Auto-generated method stub

new BasicOperand3();

}

ActionListener를 상속받아 사용

public class BasicOperand4 extends JFrame implements ActionListener{
	JTextField txtNum1;
	JTextField txtNum2;
	JLabel lblResult;

	public BasicOperand4() {
		this.setTitle("연산자");
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setSize(300, 600);

		this.setLayout(null);

		txtNum1 = new JTextField(20);
		txtNum1.setBounds(10, 10, 200, 25);
		this.add(txtNum1);

		txtNum2 = new JTextField(20);
		txtNum2.setBounds(10, 50, 200, 25);
		this.add(txtNum2);

		lblResult = new JLabel("결과출력");
		lblResult.setBounds(10, 90, 200, 25);
		this.add(lblResult);

		JButton btnAdd = new JButton("더하기");
		btnAdd.setBounds(10, 130, 200, 25);
		this.add(btnAdd);
		btnAdd.addActionListener(this);

		this.setVisible(true);
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		new BasicOperand4();
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		// TODO Auto-generated method stub

		double n1 = Double.parseDouble(txtNum1.getText().toString());
		double n2 = Double.parseDouble(txtNum2.getText().toString());
		double n = 0;

		System.out.println(e.getActionCommand());
		switch(e.getActionCommand()) {
		case "더하기" :
			n = n1 + n2;
			break;
		}
		lblResult.setText(n + "");
	}
}

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public class BasicOperand4 extends JFrame implements ActionListener{

JTextField txtNum1;

JTextField txtNum2;

JLabel lblResult;

public BasicOperand4() {

this.setTitle("연산자");

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.setSize(300, 600);

this.setLayout(null);

txtNum1 = new JTextField(20);

txtNum1.setBounds(10, 10, 200, 25);

this.add(txtNum1);

txtNum2 = new JTextField(20);

txtNum2.setBounds(10, 50, 200, 25);

this.add(txtNum2);

lblResult = new JLabel("결과출력");

lblResult.setBounds(10, 90, 200, 25);

this.add(lblResult);

JButton btnAdd = new JButton("더하기");

btnAdd.setBounds(10, 130, 200, 25);

this.add(btnAdd);

btnAdd.addActionListener(this);

this.setVisible(true);

}

public static void main(String[] args) {

// TODO Auto-generated method stub

new BasicOperand4();

}

@Override

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

double n1 = Double.parseDouble(txtNum1.getText().toString());

double n2 = Double.parseDouble(txtNum2.getText().toString());

double n = 0;

System.out.println(e.getActionCommand());

switch(e.getActionCommand()) {

case "더하기" :

n = n1 + n2;

break;

}

lblResult.setText(n + "");

}

반복문 사용해서 버튼 생성 코드 줄이기

public class BasicOperand5 extends JFrame {

	JTextField t1;
	JTextField t2;
	JLabel L1;

	String[] op = new String[] { "+", "-", "*", "/", "%", ">>", "<<", ">>>", "&", "|", "^", "~"};

	ActionListener actionListener = new ActionListener() {

		@Override
		public void actionPerformed(ActionEvent e) {
			int a = Integer.parseInt(t1.getText());
			int b = Integer.parseInt(t2.getText());
			int c = 0;

			switch (e.getActionCommand()) {
			case "+":
				c = a + b;
				break;
			case "-":
				c = a - b;
				break;
			case "*":
				c = a * b;
				break;
			case "/":
				c = a / b;
				break;
			case "%":
				c = a % b;
				break;
			case ">>":
				c = a >> b;
				break;
			case "<<":
				c = a << b;
				break;
			case ">>>":
				c = a >>> b;
				break;
			case "&":
				c = a & b;
				break;
			case "|":
				c = a | b;
				break;
			case "^":
				c = a ^ b;
				break;
			case "~":
				c = ~a;
				break;
			}

			L1.setText("" + c);
		}
	};

	public BasicOperand5() {
		this.setTitle("연산자");
		this.setSize(300, 600);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		this.setLayout(null);

		t1 = new JTextField(20);
		t1.setBounds(10, 10, 200, 25);
		this.add(t1);

		t2 = new JTextField(20);
		t2.setBounds(10, 40, 200, 25);
		this.add(t2);

		L1 = new JLabel("0");
		L1.setBounds(10, 70, 200, 25);
		this.add(L1);

		JButton btns[] = new JButton[op.length];
		for (int i = 0; i < op.length; i++) {
			btns[i] = new JButton();
			btns[i].setBounds(10, i*30 + 100, 200, 25);
			btns[i].setText(op[i]);
			this.add(btns[i]);
			btns[i].addActionListener(actionListener);
		}

		this.setVisible(true);
	}

	public static void main(String[] args) {
		new BasicOperand5();
	}
}

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public class BasicOperand5 extends JFrame {

JTextField t1;

JTextField t2;

JLabel L1;

String[] op = new String[] { "+", "-", "*", "/", "%", ">>", "<<", ">>>", "&", "|", "^", "~"};

ActionListener actionListener = new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

int a = Integer.parseInt(t1.getText());

int b = Integer.parseInt(t2.getText());

int c = 0;

switch (e.getActionCommand()) {

case "+":

c = a + b;

break;

case "-":

c = a - b;

break;

case "*":

c = a * b;

break;

case "/":

c = a / b;

break;

case "%":

c = a % b;

break;

case ">>":

c = a >> b;

break;

case "<<":

c = a << b;

break;

case ">>>":

c = a >>> b;

break;

case "&":

c = a & b;

break;

case "|":

c = a | b;

break;

case "^":

c = a ^ b;

break;

case "~":

c = ~a;

break;

}

L1.setText("" + c);

}

};

public BasicOperand5() {

this.setTitle("연산자");

this.setSize(300, 600);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.setLayout(null);

t1 = new JTextField(20);

t1.setBounds(10, 10, 200, 25);

this.add(t1);

t2 = new JTextField(20);

t2.setBounds(10, 40, 200, 25);

this.add(t2);

L1 = new JLabel("0");

L1.setBounds(10, 70, 200, 25);

this.add(L1);

JButton btns[] = new JButton[op.length];

for (int i = 0; i < op.length; i++) {

btns[i] = new JButton();

btns[i].setBounds(10, i*30 + 100, 200, 25);

btns[i].setText(op[i]);

this.add(btns[i]);

btns[i].addActionListener(actionListener);

}

this.setVisible(true);

}

public static void main(String[] args) {

new BasicOperand5();

}

자바 샘플소스코드 01

프로그램 1

package kr.ac.jj.s201712345;

import java.util.Scanner;

public class S01_Address1 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan = new Scanner(System.in);

		System.out.print("이름 : ");
		String name = scan.next();
		System.out.print("전화 : ");
		String phone = scan.next();
		System.out.print("나이 : ");
		int age = scan.nextInt();

		System.out.println("이름은 " + name + "이고 \n"
				+ "전화는 " + phone + "이고 \n"
				+ "나이는 " + age + "이다. \n"
				);
	}
}

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package kr.ac.jj.s201712345;

import java.util.Scanner;

public class S01_Address1 {

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner scan = new Scanner(System.in);

System.out.print("이름 : ");

String name = scan.next();

System.out.print("전화 : ");

String phone = scan.next();

System.out.print("나이 : ");

int age = scan.nextInt();

System.out.println("이름은 " + name + "이고 \n"

+ "전화는 " + phone + "이고 \n"

+ "나이는 " + age + "이다. \n"

);

}

프로그램2

package kr.ac.jj.s201712345;

import java.util.Scanner;

public class S01_Address2 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Person p1 = new Person();
		Person p2 = new Person();

		p1.f_scan();
		p2.f_scan();

		p1.f_print();
		p2.f_print();
	}
}

class Person{
	String name;
	String phone;
	int age;

	public Person() {	}

	public void f_scan() {
		Scanner scan = new Scanner(System.in);

		System.out.print("이름 : ");
		name = scan.next();
		System.out.print("전화 : ");
		phone = scan.next();
		System.out.print("나이 : ");
		age = scan.nextInt();
	}

	public void f_print() {
		System.out.println("이름은 " + name + "이고 \n"
				+ "전화는 " + phone + "이고 \n"
				+ "나이는 " + age + "이다. \n"
				);
	}
}

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package kr.ac.jj.s201712345;

import java.util.Scanner;

public class S01_Address2 {

public static void main(String[] args) {

// TODO Auto-generated method stub

Person p1 = new Person();

Person p2 = new Person();

p1.f_scan();

p2.f_scan();

p1.f_print();

p2.f_print();

}

class Person{

String name;

String phone;

int age;

public Person() { }

public void f_scan() {

Scanner scan = new Scanner(System.in);

System.out.print("이름 : ");

name = scan.next();

System.out.print("전화 : ");

phone = scan.next();

System.out.print("나이 : ");

age = scan.nextInt();

}

public void f_print() {

System.out.println("이름은 " + name + "이고 \n"

+ "전화는 " + phone + "이고 \n"

+ "나이는 " + age + "이다. \n"

);

}

다음 용어에 해당하는 부분은? 클래스 주석문 변수/필드 메소드 사용된 자료형 사용된 연산자