Unit 3: Fundamentals of Java ProgrammingOOP Class Design, NetBeans, JDBC & Exception Handling

// Complete Book.java Class with Encapsulation & Constructors (Pages 115-119)

package javaprograms;

public class Book {

  // Private data members (Encapsulation)

  private String title;

  private String author;

  private String publisher;

  private String genre;

  private double price;

  // Parameterized Constructor

  public Book(String t, String a, String pub, String g, double p) {

    title = t; author = a; publisher = pub; genre = g; price = p;

  }

  // Controlled Getter & Setter methods

  public double getPrice() { return price; }

  public void setPrice(double newprice) {

    if (newprice < 100) {

      System.out.println("Price cannot be set lower than 100!");

    } else {

      price = newprice;

    }

  }

  public void display() {

    System.out.println("Title: " + title + " | Author: " + author + " | Price: " + price);

  }

}

// MySQLDemo.java - Complete JDBC Query Pipeline (Page 136)

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.Statement;

import java.sql.ResultSet;

import java.sql.SQLException;

public class MySQLDemo {

  public static void main(String[] args) {

    String dbURL = "jdbc:mysql://localhost:3306/bookstore";

    String username = "root";

    String password = "password";

    try {

      // 1. Establish connection

      Connection dbCon = DriverManager.getConnection(dbURL, username, password);

      // 2. Create Statement

      Statement stmt = dbCon.createStatement();

      // 3. Execute query

      String query = "SELECT * FROM book";

      ResultSet rs = stmt.executeQuery(query);

      // 4. Iterate over rows

      while (rs.next()) {

        for (int i = 1; i <= 5; i++) {

          System.out.print(rs.getString(i) + " | ");

        }

        System.out.println();

      }

      dbCon.close();

    } catch (SQLException ex) {

      System.out.println("Database Error: " + ex.getMessage());

    }

  }

}