Compress Java objects : Zip Unzip « File « Java Tutorial

1. Java Tutorial
2. File
3. Zip Unzip

import java.io.File;
import java.io.FileOutputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.zip.GZIPOutputStream;

public class Main {
  public static void main(String[] args) throws Exception {
    User admin = new User();
    admin.setId(new Long(1));
    User foo = new User();
    foo.setId(new Long(2));
    
    ObjectOutputStream oos = new ObjectOutputStream(new GZIPOutputStream(new FileOutputStream(new File("user.dat"))));
    oos.writeObject(admin);
    oos.writeObject(foo);
    oos.flush();
    oos.close();
  }
}

class User implements Serializable {
  private Long id;

  public User() {
  }

  public Long getId() {
    return id;
  }

  public void setId(Long id) {
    this.id = id;
  }

  @Override
  public String toString() {
    StringBuilder sb = new StringBuilder();
    sb.append("id=").append(id);
    return sb.toString();
  }
}