OnJava8-Examples/compression/GZIPcompress.java

// compression/GZIPcompress.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// {java GZIPcompress GZIPcompress.java}
// {ValidateByHand}
import java.util.zip.*;
import java.io.*;

public class GZIPcompress {
  public static void
  main(String[] args) throws IOException {
    if(args.length == 0) {
      System.out.println(
        "Usage: \nGZIPcompress file\n" +
        "\tUses GZIP compression to compress " +
        "the file to test.gz");
      System.exit(1);
    }
    try(
      InputStream in = new BufferedInputStream(
        new FileInputStream(args[0]));
      BufferedOutputStream out =
        new BufferedOutputStream(
          new GZIPOutputStream(
            new FileOutputStream("test.gz")))
    ) {
      System.out.println("Writing file");
      int c;
      while((c = in.read()) != -1)
        out.write(c);
    }
    System.out.println("Reading file");
    try(
      BufferedReader in2 = new BufferedReader(
        new InputStreamReader(new GZIPInputStream(
          new FileInputStream("test.gz"))))
    ) {
      String s;
      while((s = in2.readLine()) != null)
        System.out.println(s);
    }
  }
}