Chapter 17 Exercise 9, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

17.9 (Address book)
Write a program that stores, retrieves, adds, and
updates addresses as shown in Figure 17.20. Use a
fixed-length string for storing each attribute in the address.
Use random access file for reading and writing an address. Assume
that the size of name, street, city, state, and zip is 32,
32, 20, 2, 5 bytes, respectively. [91]

public class Contact {

    String fullName;
    String street;
    String city;
    String state;
    String zip;

    public Contact(String fullName) {
        this.fullName = fullName;
    }

    public Contact(String fullName, String street, String city, String state, String zip) {
        this(fullName);
        this.street = street;
        this.city = city;
        this.state = state;
        this.zip = zip;
    }

    public String getFullName() {
        return fullName;
    }

    public void setFullName(String fullName) {
        this.fullName = fullName;
    }

    public String getStreet() {
        return street;
    }

    public void setStreet(String street) {
        this.street = street;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

    public String getZip() {
        return zip;
    }

    public void setZip(String zip) {
        this.zip = zip;
    }

    @Override
    public String toString() {
        return "Full Name: " + fullName + " | Street: " + street +
                " | City: " + city + " | State: " + state + " | Zip: " + zip;
    }

}

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.*;
import javafx.stage.Stage;

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

public class Exercise_09 extends Application {

    public static void main(String[] args) {
        Application.launch(args);
    }

    @Override
    public void start(Stage primaryStage) throws Exception {

        AddressBook addrPane = new AddressBook("/Users/Kernel/Desktop/");
        primaryStage.setScene(new Scene(addrPane));
        primaryStage.setTitle("Address Book");
        primaryStage.show();

    }

}

class BasicAddressPane extends GridPane {

    // Labels
    Label lblName;
    Label lblStreet;
    Label lblCity;
    Label lblState;
    Label lblZip;


    // TextFields
    TextField tfName;
    TextField tfStreet;
    TextField tfCity;
    TextField tfState;
    TextField tfZip;

    BasicAddressPane() {

        // Grid pane settings
        this.setPadding(new Insets(10));
        this.setHgap(10);
        this.setVgap(10);

        // Create Labels with Textfield
        lblName = createComponent("Name:", 0, tfName = new TextField(), 0);
        lblStreet = createComponent("Street:", 0, tfStreet = new TextField(), 0);
        lblCity = createComponent("City:", 140, tfCity = new TextField(), 100);
        lblState = createComponent("State:", 90, tfState = new TextField(), 40);
        lblZip = createComponent("Zip:", 130, tfZip = new TextField(), 100);

        // add name on first row
        this.add(lblName, 0, 0, 5, 1);
        tfName.setPrefColumnCount(25);

        // add street on second row
        this.add(lblStreet, 0, 1, 5, 1);
        tfStreet.setPrefColumnCount(25);

        // add city, state, zip on third row
        HBox hBox = new HBox();
        hBox.getChildren().addAll(lblCity, lblState, lblZip);
        hBox.setMaxWidth(410);
        hBox.setSpacing(5);
        this.add(hBox, 0, 2, 5, 1);

    }

    /**
     * @param name      - Name of Label
     * @param lblWidth  - Label max width: 0 = default
     * @param textField - TextField to be attached with label
     * @param tfWidth   - TextField max width: 0 = default
     * @return Label
     */
    private Label createComponent(String name, double lblWidth, TextField textField, double tfWidth) {
        Label label = new Label(name, textField);
        label.setContentDisplay(ContentDisplay.RIGHT);

        // set textfield and label custom min width if needed
        if (lblWidth > 0) {
            label.setMaxWidth(lblWidth);
        }
        if (tfWidth > 0) {
            textField.setMaxWidth(tfWidth);
        }
        return label;
    }

    protected void setTextFields(String name, String street, String city, String state, String zip) {
        tfName.setText(name);
        tfStreet.setText(street);
        tfCity.setText(city);
        tfState.setText(state);
        tfZip.setText(zip);
    }

}

class AddressBook extends BasicAddressPane {


    ArrayList<Contact> contacts;
    int index = 0;

    // Buttons
    Button btnAdd;
    Button btnFirst;
    Button btnNext;
    Button btnPrev;
    Button btnLast;
    Button btnUpdate;

    boolean isNewFile;

    String fileName = "AddressBook.dat";


    File file;

    AddressBook() {
        this(System.getProperty("user.dir")); // default path is current working directory
    }

    AddressBook(String path) {

        btnAdd = new Button("Add");
        btnFirst = new Button("First");
        btnNext = new Button("Next");
        btnPrev = new Button("Prev");
        btnLast = new Button("Last");
        btnUpdate = new Button("Update");

        // Init buttons and create bottom button panel
        HBox hBox = new HBox(15, btnAdd, btnFirst, btnPrev, btnNext, btnLast, btnUpdate);
        hBox.setAlignment(Pos.CENTER);
        this.add(hBox, 0, 3, 5, 1);

        // create listeners
        btnAdd.setOnAction(e -> addContact());
        btnUpdate.setOnAction(e -> updateContact());

        btnFirst.setOnAction(e -> {
            index = 0;
            refresh();
        });
        btnLast.setOnAction(e -> {
            index = contacts.size() - 1;
            refresh();
        });

        btnNext.setOnAction(e -> next());
        btnPrev.setOnAction(e -> previous());

        // Get address book file
        file = new File(path + fileName);
        // if file doesn't exist, create it
        try {
            isNewFile = file.createNewFile();
        } catch (IOException e) {
            e.printStackTrace();
        }
        if (!isNewFile) {
            syncContacts();
        } else {
            contacts = new ArrayList<>();

        }

        refresh();
    }

    private void previous() {
        if (index > 0) {
            index--;
            refresh();
        }
    }

    private void next() {
        if (index != contacts.size() - 1) {
            index++;
            refresh();
        }
    }

    private void refresh() {

        if (contacts.isEmpty()) return;

        Contact c = contacts.get(index);
        setTextFields(
                c.getFullName(),
                c.getStreet(),
                c.getCity(),
                c.getState(),
                c.getZip()
        );

    }

    public void addContact() {
        contacts.add(getCurrentContact());
        index = contacts.size() - 1;
        refresh();
        saveContacts();
    }

    public void updateContact() {
        contacts.remove(index);
        contacts.add(index, getCurrentContact());
        saveContacts();
    }

    public Contact getCurrentContact() {
        return new Contact(
                tfName.getText(),
                tfStreet.getText(),
                tfCity.getText(),
                tfState.getText(),
                tfZip.getText()
        );
    }

    /**
     * Reads address book and saves contacts to ArrayList
     */
    private void syncContacts() {

        // Init new buffer array
        contacts = new ArrayList<>();

        // Byte array for each field
        byte[] name = new byte[32];
        byte[] street = new byte[32];
        byte[] city = new byte[20];
        byte[] state = new byte[2];
        byte[] zip = new byte[5];

        try (FileInputStream input = new FileInputStream(file)) {

            while (input.available() >= 91 && -1 != input.read(name)) {

                input.read(street);
                input.read(city);
                input.read(state);
                input.read(zip);
                contacts.add(new Contact(
                        new String(name, "UTF-8"),
                        new String(street, "UTF-8"),
                        new String(city, "UTF-8"),
                        new String(state, "UTF-8"),
                        new String(zip, "UTF-8")
                ));

            }

        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    private void saveContacts() {

        try (FileOutputStream out = new FileOutputStream(file)) {

            for (Contact c : contacts) {
                out.write(getFixedSizeByteArray(c.getFullName(), 32));
                out.write(getFixedSizeByteArray(c.getStreet(), 32));
                out.write(getFixedSizeByteArray(c.getCity(), 20));
                out.write(getFixedSizeByteArray(c.getState(), 2));
                out.write(getFixedSizeByteArray(c.getZip(), 5));
            }

        } catch (IOException e) {
            e.printStackTrace();
        }

    }


    private byte[] getFixedSizeByteArray(String string, int fixedSize) {

        byte[] src = string.getBytes();
        byte[] fixedArray = new byte[fixedSize];
        System.arraycopy(src, 0, fixedArray, 0, Math.min(src.length, fixedSize));

        return fixedArray;
    }


}