SW 심화과정 D-9

# LinkedList 을 통한 데이터 IO

 

import java.io.*; import java.lang.*; // set/get 함수 // 구현체 class Node<T extends Object>{ T data = null; Node<T> next = null; Node(T i, Node<T> n){ this.data = i; this.next = n; } } class Score{ private String stuNum = null; private String stuName = null; private String score = null; void setStuNum(String stuNum){ this.stuNum = stuNum; } String getStuNum(){ return stuNum; } void setStuName(String stuName){ this.stuName = stuName; } String getStuName(){ return stuName; } void setScore(String score){ this.score = score; } String getScore(){ return score; } } class LinkedList<U extends Object> { Node<U> head = null; Node<U> tail = null; public LinkedList(){ this.head = new Node<U>(null, null); this.tail = this.head; } void push(U i){ tail.next = new Node<U>(i, null); tail = tail.next; } void pop(){ head = head.next; } void print() throws Exception{ for(Node<U> n = head.next; n!=null; n= n.next) { // static으로 선언해서 제너러 타입을 먼저 주면 n.data 가 정의될 수있음 DataUtil.nodePrint(n.data); } } public void save ( String fileName ) throws Exception { ObjectOutputStream out = new ObjectOutputStream (new FileOutputStream(fileName)); // out.WriteInt("데이터 갯수"); for(Node<U> n = head.next; n!=null; n= n.next) { // static으로 선언해서 제너러 타입을 먼저 주면 n.data 가 정의될 수있음 DataUtil.populate( n.data , out ); } // generic 만 주어졌을 뿐이지, 접근이 불가, (타입이 정해지지 않음) out.close(); } /*public void load(String fileName) throws IOException{ ObjectInputStream in = new ObjectInputStream(new FileInputStream(fileName)); Node<U> n = null; LinkedList<Object> ls = DataUtil.fileLoad(n.data, in); in.close(); }*/ } class DataUtil{ public static void populate(Object ob, ObjectOutputStream out) throws Exception{ if( ob instanceof Score ) { Score sc = (Score)ob; out.writeUTF(sc.getStuNum() + ", " + sc.getStuName() + ", " + sc.getScore()); } } public static void nodePrint(Object ob) throws Exception{ if( ob instanceof Score ) { Score sca = (Score)ob; System.out.println("학번 : " + sca.getStuNum() + "이름 : " + sca.getStuName() + "점수 : " + sca.getScore()); } } public static Object fileLoad(Object ob, String fileName) throws Exception{ ObjectInputStream in = new ObjectInputStream(new FileInputStream(fileName)); String a = null; if( ob instanceof Score ) { LinkedList<Object> scoreLS = new LinkedList<Object>(); while(true){ try{ a = in.readUTF(); Score sc = new Score(); // Score sc = (Score) ob; // load에서 ob는 데이터 타입을 바꿔주는 역할, 이걸 새로운 인스턴스로 생성 X String[] array = a.split(","); sc.setStuNum(array[0]); sc.setStuName(array[1]); sc.setScore(array[2]); scoreLS.push(sc); System.out.println(sc.getStuName()); } catch(Exception e){ System.out.println(e); break; } } return scoreLS; } return null; } } public class Test095{ public static void main(String [] args) throws Exception { BufferedReader br = new BufferedReader( new InputStreamReader(System.in)); String l = null; LinkedList<Score> ll = null; while (!("quit".equals(l))) { System.out.println("MENU"); System.out.println("1. 새 자료"); System.out.println("2. 자료 입력"); System.out.println("3. 파일 저장"); System.out.println("4. 파일에서 불러오기"); System.out.println("5. 출력하기"); l = br.readLine(); if( l.equals("1")){ ll = new LinkedList<Score>(); System.out.println("새 자료가 생성되었습니다."); } else if(l.equals("2")){ Score stu = new Score(); System.out.print("학번을 입력해주세요"); l = br.readLine(); stu.setStuNum(l); System.out.print("이름을 입력해주세요"); l = br.readLine(); stu.setStuName(l); System.out.print("점수를 입력해주세요"); l = br.readLine(); stu.setScore(l); ll.push(stu); // 학번, 점수 } else if(l.equals("3")){ // String l = score.dat System.out.println("파일 이름을 입력하세요. > "); l = br.readLine(); ll.save(l); // 파일 이름 받기 } else if(l.equals("4")){ System.out.println("파일 이름을 입력하세요. > "); l = br.readLine(); ll = (LinkedList<Score>)(DataUtil.fileLoad(new Score(), l)); ll.print(); } else if(l.equals("5")){ ll.print(); } } br.close(); } }

 

 

# Socket - Server 측면

 

 

package temp; import java.net.*; import java.io.*; public class Test094S { public static void main( String [] args ) throws Exception{ ServerSocket svr = new ServerSocket(1123); boolean alive = true; while (alive) { Socket skt = svr.accept(); ObjectInputStream in = new ObjectInputStream( skt.getInputStream() ); ObjectOutputStream out = new ObjectOutputStream( skt.getOutputStream() ); String fileName = in.readUTF(); if( fileName.equals("die")){ alive = false; out.writeInt(9); out.flush(); } else { File fle = new File( "C:\\A\\" + fileName ); if( !fle.exists() ){ out.writeInt( 404 ); out.flush(); } else { out.writeInt( 200 ); out.flush(); InputStream fin = new FileInputStream( "C:\\A\\" + fileName); byte[] buf = new byte[8*1024]; int len = 0; while(( len = fin.read( buf ) ) != -1 ){ out.write( buf, 0, len ); out.flush(); } fin.close(); } } out.close(); in.close(); skt.close(); } svr.close(); } }

 

# Socket - Client 측면

 

package temp; import java.net.*; import java.io.*; public class Test094C { public static void main( String [] args ) throws Exception{ Socket skt = new Socket("127.0.0.1", 1123); ObjectOutputStream out = new ObjectOutputStream(skt.getOutputStream()); ObjectInputStream in = new ObjectInputStream(skt.getInputStream()); out.writeUTF(args[0]); out.flush(); int code = in.readInt(); if(code == 404){ System.out.println("파일 없어요.. "); } else if(code == 200){ OutputStream fout = new FileOutputStream(args[0]); byte[] buf = new byte[8*1024]; int len = 0; while((len = in.read(buf)) != -1){ fout.write(buf, 0, len); } fout.close(); System.out.println("다운 완료"); } in.close(); out.close(); skt.close(); } }