[바이트 스트림] 데이터 압축 및 해제 - GZIPOutputStream & GZIPInputStream 사용

데이터 압축

 

package ch12;   import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.util.zip.GZIPOutputStream;   public class GZip {        public static int sChunk = 8192;          public static void main(String[] args) {               if (args.length != 1) {                      System.out.println("Usage: GZip source");                      return;               }               // create output stream               String zipname = args[0] + ".gz";               GZIPOutputStream zipout;               try {                      FileOutputStream out = new FileOutputStream(zipname);                      zipout = new GZIPOutputStream(out);               } catch (IOException e) {                      System.out.println("Couldn't create " + zipname + ".");                      return;               }               byte[] buffer = new byte[sChunk];               // compress the file               try {                      FileInputStream in = new FileInputStream(args[0]);                      int length;                      while ((length = in.read(buffer, 0, sChunk)) != -1)                            zipout.write(buffer, 0, length);                      in.close();               } catch (IOException e) {                      System.out.println("Couldn't compress " + args[0] + ".");               }               try {                      zipout.close();               } catch (IOException e) {               }        } }

 

 

압축 해제

 

package ch12;   import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.util.zip.GZIPInputStream;   public class GUnzip {        public static int sChunk = 8192;          public static void main(String[] args) {               if (args.length != 1) {                      System.out.println("Usage: GUnzip source");                      return;               }               // create input stream               String zipname, source;               if (args[0].endsWith(".gz")) {                      zipname = args[0];                      source = args[0].substring(0, args[0].length() - 3);               } else {                      zipname = args[0] + ".gz";                      source = args[0];               }               GZIPInputStream zipin;               try {                      FileInputStream in = new FileInputStream(zipname);                      zipin = new GZIPInputStream(in);               } catch (IOException e) {                      System.out.println("Couldn't open " + zipname + ".");                      return;               }               byte[] buffer = new byte[sChunk];               // decompress the file               try {                      FileOutputStream out = new FileOutputStream(source);                      int length;                      while ((length = zipin.read(buffer, 0, sChunk)) != -1)                            out.write(buffer, 0, length);                      out.close();               } catch (IOException e) {                      System.out.println("Couldn't decompress " + args[0] + ".");               }               try {                      zipin.close();               } catch (IOException e) {               }        } }