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JAVA

221221_Interface,상속

by 경 훈 2022. 12. 21.

자바에서 자료를 입력하는 방법

1.직접대입

2.세터를 이용 --> 스캐너를 이용해서 키보드 입력

3.파일처리 ->세터를 이용

 

* 파일 생성

단점 : 길이가 동일(레코드)해야됨

 

자료표현

bit -> 8bit(=byte) -> word -> record(처리단위)

-> file -> data base -> data bank

 

자바에서 상속(inheritence) 은 중요

:어떤 클래스를 상속 받으면 그 클래스의 필드명과 메소드를 그냥 사용가능

 

인터페이스는 두개 이상 상속 받아도 상관없다.

클래스는 오직 하나만 상속가능

 

**정렬

DTO 클래스에 implements Comparable 인터페이스 상속후

예제 )

수정렬

if(avg>o.avg)return -1;

else
return 1;

이름정렬

return name.compareTo(o.name);

 

출력 out 쪽에

Collections.sort(list); 입력 후 결과확인

 

package day13_file;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class File_Test {

	public static void main(String[] args) throws IOException {
		FileReader fr = new FileReader("c:/data/1221.txt");
		BufferedReader br = new BufferedReader(fr);
		System.out.println("반\t이름\t국어\t영어\t수학");
		System.out.println("=================================");
		while(true) {
			String str = br.readLine();
			if(str == null) break;
			int ban = Integer.parseInt(str.substring(0, 1));
			String name = str.substring(1, 4);
			int kor = Integer.parseInt(str.substring(4, 7));
			int eng = Integer.parseInt(str.substring(7, 10));
			int math = Integer.parseInt(str.substring(10, 13));
		
			System.out.println(ban+"\t"+name+"\t"+kor+"\t"+eng+"\t"+math);
			
		}
	}
}
package day13_file;
//반 오름차순 정렬후 출력
public class ScoreDTO implements Comparable<ScoreDTO>{
	int ban;
	String name;
	int kor,eng,math,tot;
	double avg;
	char hak;
	//
	
	//
	public ScoreDTO() {}
	public ScoreDTO(int ban, String name, int kor, int eng, int math) {
		super();
		this.ban = ban;
		this.name = name;
		this.kor = kor;
		this.eng = eng;
		this.math = math;
	}
	public int getBan() {
		return ban;
	}
	public void setBan(int ban) {
		this.ban = ban;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getKor() {
		return kor;
	}
	public void setKor(int kor) {
		this.kor = kor;
	}
	public int getEng() {
		return eng;
	}
	public void setEng(int eng) {
		this.eng = eng;
	}
	public int getMath() {
		return math;
	}
	public void setMath(int math) {
		this.math = math;
	}
	public int getTot() {
		return tot;
	}
	public void setTot(int tot) {
		this.tot = tot;
	}
	public double getAvg() {
		return avg;
	}
	public void setAvg(double avg) {
		this.avg = avg;
	}
	public char getHak() {
		return hak;
	}
	public void setHak(char hak) {
		this.hak = hak;
	}
	@Override
	public int compareTo(ScoreDTO o) {
//		if(o.ban>ban) return -1;
//		else
//		return 1;
		return name.compareTo(o.name);
	}
}

 

package day13_file;

import java.io.IOException;
import java.util.Scanner;

public class ScoreMenu {

	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		ScoreDAO dao = new ScoreDAO();
		while(true) {
			System.out.println("1.자료입력");
			System.out.println("2.자료출력");
			System.out.println("3.자료삭제");
			System.out.println("0.작업종료");
			System.out.print("원하는 작업번호를 입력하시오");
			int n = sc.nextInt();
			switch(n) {
			case 0:System.exit(0);break;
			case 1:dao.insert();break;
			case 2:dao.out();break;
			case 3:dao.delete();break;
			}
		}
	}
}

 

package day13_file;

public class Total {
	public int tot(int kor, int eng, int math) {//총점을 구할려면
		return kor+eng+math; 
	}
}

 

package day13_file;

public class Average {
	public double avg(int tot) {
		return (double)tot/3;
	}
}

 

package day13_file;

public class Grade {
	public char grade(double avg) {
		char grade;
		switch ((int)avg/10) {
		case 10:
		case 9:grade='A';break;
		case 8:grade='B';break;
		case 7:grade='C';break;
		case 6:grade='D';break;
		default:grade='F';break;
		}
		return grade;
	}
}

 

package day13_file;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Collections;

public class ScoreDAO {//db에 접근하는 기능들을 모아놓은 클래스
	ArrayList<ScoreDTO> list = new ArrayList<ScoreDTO>();
	public void insert() throws IOException {//DTO클래스 set함수에 값을 넣는
		FileReader fr = new FileReader("c:/data/1221.txt");
		BufferedReader br = new BufferedReader(fr);
		while(true) {
			String str = br.readLine();
			if(str == null)break;
			int ban = Integer.parseInt(str.substring(0, 1));
			String name = str.substring(1, 4);
			int kor = Integer.parseInt(str.substring(4, 7));
			int eng = Integer.parseInt(str.substring(7, 10));
			int math = Integer.parseInt(str.substring(10, 13));
//			int tot = kor+eng+math;
//			double avg = (double)tot/3;
			ScoreDTO dto = new ScoreDTO();
			dto.setBan(ban);
			dto.setName(name);
			dto.setKor(kor);
			dto.setEng(eng);
			dto.setMath(math);
			//각각의 클래스와 메소드 생성후 총점,평균,학점을 구하는
			Total tt = new Total();
			dto.setTot(tt.tot(dto.getKor(),dto.getEng(),dto.getMath()));
//			dto.setTot(tot);
			Average av = new Average();
			dto.setAvg(av.avg(dto.getTot()));
//			dto.setAvg(avg);
			Grade gr = new Grade();
			dto.setHak(gr.grade(dto.getAvg()));
//			char hak;
//			if(avg>=90)hak='A';
//			else if(avg>=80) hak='B';
//			else if(avg>=70) hak='C';
//			else if(avg>=60) hak='D';
//			else hak='F';
//			dto.setHak(hak);
			list.add(dto);
		}
	}
	public void out() {
		System.out.println("반\t이름\t국어\t영어\t수학\t총점\t평균\t학점");
		System.out.println("===========================================================");
		DecimalFormat df = new DecimalFormat("#,#00.0");
		Collections.sort(list);
		for(ScoreDTO a:list) {
			System.out.print(a.getBan()+"\t");
			System.out.print(a.getName()+"\t");
			System.out.print(a.getKor()+"\t");
			System.out.print(a.getEng()+"\t");
			System.out.print(a.getMath()+"\t");
			System.out.print(a.getTot()+"\t");
			System.out.print(df.format(a.getAvg())+"\t");
			System.out.println(a.getHak());
		}
	}
	public void delete() {
		
	}
}
package day13_inher;
class Father{
	String name;
	int age;
	public void out() {
		System.out.println("이름 : "+name);
		System.out.println("나이 : "+age);
	}
}
class Son extends Father {
	
}
public class Inheri_test {

	public static void main(String[] args) {
		Father ff = new Father();
		ff.name="홍길동";
		ff.age=33;
		ff.out();
		Son ss = new Son();
		ss.name="한라산";
		ss.age=23;
		ss.out();
	}
}
package day13_inher;
class One {
	int a,b;
}
interface Twosu {
	public void out();
}
class Hap extends One implements Twosu{
	@Override
	public void out() {
		System.out.println(a+"+"+b+"="+(a+b));
	}
}
class Gop extends One implements Twosu{
	@Override
	public void out() {
		System.out.println(a+"*"+b+"="+(a*b));
	}
}
class Cha extends One implements Twosu{
	@Override
	public void out() {
		System.out.println(a+"-"+b+"="+(a-b));
	}
}
public class Inheri_test {

	public static void main(String[] args) {
		Hap hh = new Hap();
		hh.a=62;
		hh.b=34;
		hh.out();
		Gop gg= new Gop();
		gg.a=62;
		gg.b=34;
		gg.out();
		Cha cc = new Cha();
		cc.a=62;
		cc.b=34;
		cc.out();
	}
}
package day_inher2;
class Animal {
	String name,food;
	int age;
	boolean fly;
	String bigo;
	String per;
}
class Rabbit extends Animal{
	public void out() {
		System.out.println("이름 : "+name);
		System.out.println("나이 : "+age);
		System.out.println("음식 : "+food);
		if(fly==true) {
			bigo="O 날수있다";
		}
		else {
			bigo="X 날수없다";
		}
		System.out.println("날개 : "+bigo);
		if(food.equals("육류")) {
			per="난폭하다";
		}
		else {
			per="온순하다";
		}
		System.out.println("성격 : "+per);
		System.out.println("============");
	}
}
class Tiger extends Animal{
	public void out() {
		System.out.println("이름 : "+name);
		System.out.println("나이 : "+age);
		System.out.println("음식 : "+food);
		if(fly==true) {
			bigo="O 날수있다";
		}
		else {
			bigo="X 날수없다";
		}
		System.out.println("날개 : "+bigo);
		if(food.equals("육류")) {
			per="난폭하다";
		}
		else {
			per="온순하다";
		}
		System.out.println("성격 : "+per);
		System.out.println("============");
	}
}
class Eagle extends Animal{
	public void out() {
		System.out.println("이름 : "+name);
		System.out.println("나이 : "+age);
		System.out.println("음식 : "+food);
		if(fly==true) {
			bigo="O 날수있다";
		}
		else {
			bigo="X 날수없다";
		}
		System.out.println("날개 : "+bigo);
		if(food.equals("육류")) {
			per="난폭하다";
		}
		else {
			per="온순하다";
		}
		System.out.println("성격 : "+per);
		System.out.println("============");
	}
}

public class Her_Test {
	public static void main(String[] args) {
		Rabbit rr = new Rabbit();
		rr.age=2;
		rr.name="토끼";
		rr.food="채소";
		rr.fly=false;
		rr.out();
		
		Tiger tt = new Tiger();
		tt.age=4;
		tt.name="호랑이";
		tt.food="육류";
		tt.fly=false;
		tt.out();
		
		Eagle ee = new Eagle();
		ee.age=12;
		ee.name="독수리";
		ee.food="육류";
		ee.fly=true;
		ee.out();
	}
	
	
}
package day13_Classinher;

public class ScoreDTO extends Hakwon implements Comparable<ScoreDTO>{
	int kor,eng,mat;
	int tot;
	double avg;
	char hak;
	
	public int getKor() {
		return kor;
	}
	public void setKor(int kor) {
		this.kor = kor;
	}
	public int getEng() {
		return eng;
	}
	public void setEng(int eng) {
		this.eng = eng;
	}
	public int getMat() {
		return mat;
	}
	public void setMat(int mat) {
		this.mat = mat;
	}
	public int getTot() {
		return tot;
	}
	public void setTot(int tot) {
		this.tot = tot;
	}
	public double getAvg() {
		return avg;
	}
	public void setAvg(double avg) {
		this.avg = avg;
	}
	public char getHak() {
		return hak;
	}
	public void setHak(char hak) {
		this.hak = hak;
	}
	@Override
	public int compareTo(ScoreDTO o) {
		if(avg>o.avg)return -1;
		else
		return 1;
	}
}

 

package day13_Classinher;

public class Hakwon {
	String name,junum;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getJunum() {
		return junum;
	}
	public void setJunum(String junum) {
		this.junum = junum;
	}
}

 

package day13_Classinher;

public class Process {
	public int tot(int kor,int eng,int mat) {
		return kor+eng+mat;
	}
	public double avg(int tot) {
		return (double)tot/3;
	}
	public char hak(double avg) {
		char hak;
		switch ((int)avg/10) {
		case 10:
		case 9:hak = 'A';break;
		case 8:hak = 'B';break;
		case 7:hak = 'C';break;
		case 6:hak = 'D';break;
		default:hak = 'F';break;
		}
		return hak;
	}
}

 

package day13_Classinher;

import java.io.IOException;
import java.util.Scanner;

public class ScoreMain {

	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		ScoreDAO dao = new ScoreDAO();
		while(true) {
			System.out.print("0:기능중지"+"\t");
			System.out.print("1:입력"+"\t");
			System.out.println("2:출력"+"\t");
			System.out.print("3:삭제"+"\t");
			System.out.print("4:검색"+"\t");
			System.out.println("5:수정");
			System.out.print("원하는 번호 입력");
			int n = sc.nextInt();
			switch (n) {
			case 0:System.exit(0);break;
			case 1:dao.insert();break;
			case 2:dao.out();break;
			case 3:dao.delete();break;
			case 4:dao.search();break;
			case 5:dao.update();break;
			}
		}
	}
}

 

package day13_Classinher;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class ScoreDAO {
	ArrayList<ScoreDTO> list = new ArrayList<ScoreDTO>();
	DecimalFormat df = new DecimalFormat("#,#00.00");
	public void insert() throws IOException {//입력
		//홍길동901230-1234567099100100
		FileReader fr = new FileReader("c:/data/12212.txt");
		BufferedReader br = new BufferedReader(fr);
		while(true) {
			ScoreDTO dto = new ScoreDTO();
			String str = br.readLine();
			if(str==null)break;
			String name = str.substring(0, 3);
			String junum = str.substring(3, 17);
			int kor = Integer.parseInt(str.substring(17, 20));
			int eng = Integer.parseInt(str.substring(20, 23));
			int mat = Integer.parseInt(str.substring(23, 26));
			dto.setName(name);
			dto.setJunum(junum);
			dto.setKor(kor);
			dto.setEng(eng);
			dto.setMat(mat);
			Process pc = new Process();
			dto.setTot(pc.tot(dto.getKor(), dto.getEng(), dto.getMat()));
			dto.setAvg(pc.avg(dto.getTot()));
			dto.setHak(pc.hak(dto.getAvg()));
			list.add(dto);
		}
	}
	public void out() {//출력
		System.out.println("이름\t주민번호\t\t국어\t영어\t수학\t합계\t평균\t학점");
		System.out.println("====================================================");
		Collections.sort(list);
		for(ScoreDTO a:list) {
			System.out.print(a.getName()+"\t");
			System.out.print(a.getJunum()+"\t");
			System.out.print(a.getKor()+"\t");
			System.out.print(a.getEng()+"\t");
			System.out.print(a.getMat()+"\t");
			System.out.print(a.getTot()+"\t");
			System.out.print(df.format(a.getAvg())+"\t");
			System.out.println(a.getHak());
		}
	}
	public void delete() {//삭제
		Scanner sc = new Scanner(System.in);
		int po = -1;
		System.out.println("검색할 이름을 입력하시오");
		String dname = sc.next();
		for(int i=0;i<list.size();i++) {
			if(list.get(i).getName().equals(dname)) {
				po=i;
				break;
			}
		}
		if(po==-1) {
			System.out.println(dname+"은 없는 이름입니다.");
		}
		else {
			System.out.println("이름 : "+list.get(po).getName());
			System.out.println("주민 : "+list.get(po).getJunum());
			System.out.println("국어 : "+list.get(po).getKor());
			System.out.println("영어 : "+list.get(po).getEng());
			System.out.println("수학 : "+list.get(po).getMat());
			System.out.println("위 데이터를 삭제 할까요?");
			String qq = sc.next();
			if(qq.equals("Y")||qq.equals("y")||qq.equals("ㅛ")) 
			{
				list.remove(po);
				System.out.println("삭제했습니다");
			}
			else {
				System.out.println("삭제보류");
			}
		}
	}
	public void search() {//검색
		Scanner sc =new Scanner(System.in);
		int po = -1;
		System.out.println("검색할 이름을 입력하시오");
		String sname = sc.next();
		for(int i=0;i<list.size();i++) {
			if(list.get(i).getName().equals(sname)) {
				po=i;
				break;
			}
		}
		if(po==-1) {
			System.out.println(sname+"은 없는 이름입니다.");
		}
		else {
			System.out.println("이름 : "+list.get(po).getName());
			System.out.println("주민 : "+list.get(po).getJunum());
			System.out.println("국어 : "+list.get(po).getKor());
			System.out.println("영어 : "+list.get(po).getEng());
			System.out.println("수학 : "+list.get(po).getMat());
			System.out.println("총점 : "+list.get(po).getTot());
			System.out.println("평균 : "+df.format(list.get(po).getAvg()));
			System.out.println("학점 : "+list.get(po).getHak());
			System.out.println("위 데이터는 검색한 데이터입니다.");
			System.out.println("");
		}
	}
	public void update() {//수정
		
	}
}
package day4_jsp3;

public class ScoreDTO implements Comparable<ScoreDTO>{
	String name;
	int kor,eng,mat;
	int tot;
	public ScoreDTO() {}
	public ScoreDTO(String name, int kor, int eng, int mat, int tot) {
		super();
		this.name = name;
		this.kor = kor;
		this.eng = eng;
		this.mat = mat;
		this.tot = tot;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getKor() {
		return kor;
	}
	public void setKor(int kor) {
		this.kor = kor;
	}
	public int getEng() {
		return eng;
	}
	public void setEng(int eng) {
		this.eng = eng;
	}
	public int getMat() {
		return mat;
	}
	public void setMat(int mat) {
		this.mat = mat;
	}
	public int getTot() {
		return tot;
	}
	public void setTot(int tot) {
		this.tot = tot;
	}
	@Override
	public int compareTo(ScoreDTO o) {
		if(tot<o.tot) return 1;
		else return -1;
//		return name.compareTo(o.name);
	}
}

 

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<style type="text/css">
table {
	border-collapse:collapse;
	border-color: orange;
	text-align: center;
}
th,td {
	background-color: #dddddd;
	text-align: center;
}
input {
	background-color: #eeeeee;
}
</style>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<form action="scoresave.jsp" method="post">
		<table border="2" align="center">
			<caption>회원정보입력</caption>
			<tr>
				<th>이름</th>
				<td><input type="text" name="name"></td>
			</tr>
			<tr>
				<th>국어</th>
				<td><input type="text" name="kor"></td>
			</tr>
			<tr>
				<th>영어</th>
				<td><input type="text" name="eng"></td>
			</tr>
			<tr>
				<th>수학</th>
				<td><input type="text" name="mat"></td>
			</tr>
			<tr>
				<td colspan="2" align="center">
				<input type="submit" value="전송">
				<input type="reset" value="초기화">
				</td>
			</tr>
		</table>
	</form>
</body>
</html>

 

<%@page import="java.util.Collections"%>
<%@page import="day4_jsp3.ScoreDTO"%>
<%@page import="java.util.ArrayList"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<style type="text/css">
table {
	border-collapse:collapse;
	border-color: orange;
	text-align: center;
}
th,td {
	background-color: #eeeeee;
	text-align: center;
}
</style>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<%!
	String name;
	int kor,eng,mat,tot;
	ArrayList<ScoreDTO> list = new ArrayList<ScoreDTO>();
	%>
	<%
	request.setCharacterEncoding("utf-8");
	name=request.getParameter("name");
	kor=Integer.parseInt(request.getParameter("kor"));
	eng=Integer.parseInt(request.getParameter("eng"));
	mat=Integer.parseInt(request.getParameter("mat"));
	tot=kor+eng+mat;
	int grade = 0;
	ScoreDTO dto = new ScoreDTO();
	list.add(new ScoreDTO(name,kor,eng,mat,tot));
	%>
	<table border="1" align="center">
		<tr>
			<th>이름</th><th>국어</th><th>영어</th><th>수학</th><th>총점</th><th>순위</th>
		</tr>
		<%
		Collections.sort(list); 
		for(ScoreDTO a:list) {
			name=a.getName();
			kor=a.getKor();
			eng=a.getEng();
			mat=a.getMat();
			tot=a.getTot();
			grade++;
			%>
		<tr>
			<td><%=name%></td>
			<td><%=kor%></td>
			<td><%=eng%></td>
			<td><%=mat%></td>
			<td><%=tot%></td>
			<td><%=grade%></td>
		<tr>
		<%
		}
		%>
	</table>
	<br>
	<div align="center">
	<a href="scoreForm.jsp"><input type="button" value="입력으로"></a>
	</div>
</body>
</html>

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