import java.io.*;
import java.util.*;

class Record implements Serializable {
    private int id;
    private String name;
        
    public Record(int id, String name) { setID(id); setName(name); }
    public void setID(int id) { this.id= id; }
    public void setName(String name) {
        if (name == null) this.name = "";
        else this.name = name;
    }
    public int getID() { return id; }
    public String getName() { return name; }
    public String toString() { return id + ": " + name; }
}

class Seq3Exception extends Exception {
    public Seq3Exception() {}
    public Seq3Exception(String msg) { super(msg); }
}

class Seq3 {
    private ObjectOutputStream out = null;
    public Seq3(String filename) throws Seq3Exception {
        try {
            out = new ObjectOutputStream(new FileOutputStream(filename));
        } catch (SecurityException e1) {
            throw new Seq3Exception("Write access to file denied");
        } catch (FileNotFoundException e2) {
            throw new Seq3Exception("File not found");
        } catch (IOException e3) {
            throw new Seq3Exception("I/O Exception");
        }
    }
    
    public void close() {
        if (out != null)  {
            try {
                out.close();
            } catch (IOException e) {}
        }
    }
    
    public void addRecord(Record r) {
        try {
            out.writeObject(r);
        } catch (Exception e) {
            System.err.println("Error: " + e.getMessage());
        }
    }
}

public class TestSeq3 {
    public static void main(String[] args) {
        try {
            Seq3 outfile = new Seq3("records3.txt");
            Scanner in = new Scanner(System.in);
inloop:
            while (true) {
                try {
                    int id = -1;
                    while (id <= 0) {
                        System.out.print("Enter record ID# (^z to exit on Windows, ^d on Mac/UNIX): ");
                        if (!in.hasNext()) break inloop;
                        try {
                            id = Integer.parseInt(in.nextLine());
                            if (id <= 0) System.out.println("ID# must be greater than 0");
                        } catch (NumberFormatException e3) {
                            System.out.println("ID must be a positive integer");
                            id = -1;
                            continue;
                        }
                    }
                    System.out.print("Enter name: ");
                    String name = in.nextLine();
                    outfile.addRecord(new Record(id, name));
                } catch (NoSuchElementException e2) {
                    System.err.println("Invalid input. Try again.");
                    in.nextLine();
                }
            }
            outfile.close();
        } catch (Seq3Exception e1) {
            System.err.println("Error: " + e1.getMessage());
        }
    }
}