import ToolKit.Contact;
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;
/**
* (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]
* <p>
* Created by Luiz Arantes Sa on 10/5/14.
*/
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;
}
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Java is a very popular general-purpose programming language, it is class-based and object-oriented. Java was developed by James Gosling at Sun Microsystems ( later acquired by Oracle) the initial release of Java was in 1995. Java 17 is the latest long-term supported version (LTS). As of today, Java is the world's number one server programming language with a 12 million developer community, 5 million students studying worldwide and it's #1 choice for the cloud development.
short x = 999; // -32768 to 32767
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When ever you want to perform a set of operations based on a condition If-Else is used.
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For loop is used to iterate a set of statements based on a condition. Usually for loop is preferred when number of iterations is known in advance.
for(Initialization; Condition; Increment/decrement){
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While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
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Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
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Class is the blueprint of an object, which is also referred as user-defined data type with variables and functions. Object is a basic unit in OOP, and is an instance of the class.
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class Mobile {
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public class Greeting {
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Collection is a group of objects which can be represented as a single unit. Collections are introduced to bring a unified common interface to all the objects.
Collection Framework was introduced since JDK 1.2 which is used to represent and manage Collections and it contains:
This framework also defines map interfaces and several classes in addition to Collections.
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|---|---|
| Set | Set is a collection of elements which can not contain duplicate values. Set is implemented in HashSets, LinkedHashSets, TreeSet etc |
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| Queue | FIFO approach, while instantiating Queue interface you can either choose LinkedList or PriorityQueue. |
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| Map | Map contains key-values pairs which don't have any duplicates. Map is implemented in HashMap, TreeMap etc. |