너구리의 IT일기

package ch05; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStreamReader; public class InputStreamReaderTest { public static void main(String[] args) { //try(FileInputStream fi = new FileInputStream("assets/input2.txt")){ 읽고 쓰는건 메인기반스트림만 try(InputStreamReader isr = new InputStreamReader(new FileInputStream("assets/input2.txt"))){ //보조는 읽고 쓰기가 안됨 (이렇게쓰면 보조기반을 한꺼번..

package ch04; import java.io.FileWriter; import java.io.IOException; public class FileWriterTest { public static void main(String[] args) { try (FileWriter fw = new FileWriter("write.txt")) { fw.write('A'); char buf[] = {'B','C','D','E','F','G'}; fw.write(buf); fw.write("안녕하세요"); fw.write(buf,1,2); } catch (IOException e) { System.out.println(e); } System.out.println("출력이 완료되었습니다."); } }

package ch03; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; public class FileOutputStreamTest3 { public static void main(String[] args) { try(FileOutputStream fos = new FileOutputStream("output3.txt", false)){ byte[] bs = new byte[26]; byte data = 65; //아스키코드값 for (int i = 0; i < bs.length; i++) { bs[i] = data; data++; } fos.write(bs, 2, 10); ..

package ch03; import java.io.FileNotFoundException; import java.io.FileOutputStream; public class FileOutputStreamTest2 { public static void main(String[] args) throws FileNotFoundException { FileOutputStream fos = new FileOutputStream("output2.txt",false); //java9부터 제공되는 기능 try(fos){ byte[] bs= new byte[26]; byte data =65; for (int i = 0; i < bs.length; i++) { bs[i] = data; data++; } fos.write(..

package ch03; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; public class FileOutputStreamTest1 { public static void main(String[] args) { try(FileOutputStream fos = new FileOutputStream("output.txt",true)){ //false 써야 새롭게 덮어쓰는 것을 막아주는 //true를 쓰면 계속 중복 (덮어쓸수있게 코딩을 할수있게하고싶을때) fos.write(65); fos.write(66); fos.write(67); } catch (FileNotFoundExce..

package ch02; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; public class FileInputStreamTest5 { public static void main(String[] args) { try(FileInputStream fis = new FileInputStream ("assets/input2.txt")){ byte[] bs = new byte[10]; //fis.read(bs, 0, 5); //0부터 5까지만 읽을수있도록 //for (byte b : bs) { //System.out.println((char)b); //} System.out.print..

package ch02; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; public class FileInputStreamTest4 { public static void main(String[] args) { try(FileInputStream fis = new FileInputStream("assets/input2.txt")){ byte[] bs = new byte[10]; //배열이 10개라 10/10/6이지만 10개를 채워서 다읽게된다 //ABCDEFGHIJKLMNOPQRSTUVWXYZ(QRST) int i; while ((i = fis.read(bs))!=-1) { //..

package ch02; import java.io.FileInputStream; public class FileInputStreamTest3 { public static void main(String[] args) { try(FileInputStream fis = new FileInputStream("assets/input.txt")){ int i ; while((i=fis.read())!= -1) { System.out.println((char)i); } }catch (Exception e) { System.out.println(e); }//auto close 기능이 자동으로 탑재 } }

package ch02; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; public class FileInputStreamTest2 { public static void main(String[] args) { FileInputStream fis = null; try { fis = new FileInputStream("assets/input.txt"); int i; while((i= fis.read())!= -1) { //데이터 있을때 까지 읽는데 더이상 반환할게없으면 //-1해서 while문을 멈춘다 System.out.println((char)i); //바이트단위를 문자로 }..

package ch02; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; public class FileInputStreamTest1 { //파일에 있는 소스코드를 읽거나 //인트나 스트링을 파일로 쓰게끔 //여기에적는 맴버변수는 자동으로 null이되지만 public static void main(String[] args) { FileInputStream fis = null; //매서드나 함수안에는 null값을 주어서 초기값을 설정해주어야 오류가 적다 try { fis = new FileInputStream("assets/input.txt"); System.out.println(..