[JavaEE] MVC

1. Tạo project DemoMVC
2. Add web.xml > mở lên vào tab Pages > điền vào Welcome files: ControllerServlet
3. Tạo Servlet ControllerServlet trong package vn.aptech.controller
	Thêm đoạn sau:
	String action = request.getParameter("aciton");
	BookDal dal = new BookDal();
	if (action == null) {
		request.setAttribute("books", dal.getBooks());
		request.getRequestDispatcher("index.jsp").forward(request, response);
	}
4. tạo Class Book trong vn.aptech.entity
	tạo hàm dựng không tham số
	Thêm: int bookID, price; String title;
	Và refactor
5. Add JAR vào libraries driver loại 4 MSSQL
6. Tạo Class BookDal trong vn.aptech.dal thêm hàm dựng kg tham số và thêm đoạn sau:
	private Connection getConnection() throws ClassNotFoundException, SQLException{
        Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
        String url = "jdbc:sqlserver://localhost:1433;databaseName=Demo";
        return DriverManager.getConnection(url,"sa","password123");
    }

	public List<Book> getBooks() {
        List<Book> result = new ArrayList<>();
        try {
            Connection con = getConnection();
            String q = "SELECT * FROM Books";
            PreparedStatement stm = con.prepareStatement(q);
            ResultSet rs = stm.executeQuery();
            while (rs.next()) {
                Book b = new Book();
                b.setBookID(rs.getInt(1));
                b.setTitle(rs.getString(2));
                b.setPrice(rs.getInt(3));
                result.add(b);
            }
            rs.close();
            stm.close();
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    public Book getBook(int id) {
        Book b = null;
        try {
            Connection con = getConnection();
            String q = "SELECT * FROM Books WHERE BookID=?";
            PreparedStatement stm = con.prepareStatement(q);
            stm.setInt(1, id);
            ResultSet rs = stm.executeQuery();
            if (rs.next()) {
                b.setBookID(rs.getInt(1));
                b.setTitle(rs.getString(2));
                b.setPrice(rs.getInt(3));
            }

            rs.close();
            stm.close();
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return b;
    }

    public boolean add(Book b) {
        try {
            Connection con = getConnection();
            String q = "INSERT INTO Books (BookID, Title, Price) VALUES (?, ?, ?)";
            PreparedStatement stm = con.prepareStatement(q);
            stm.setInt(1, b.getBookID());
            stm.setString(2, b.getTitle());
            stm.setInt(3, b.getPrice());
            int rs = stm.executeUpdate();
            if (rs > 0) {
                stm.close();
                con.close();
                return true;
            } else {
                stm.close();
                con.close();
                return false;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }

    public boolean update(Book b) {
        try {
            Connection con = getConnection();
            String q = "UPDATE Books SET Title = ?, Price = ? WHERE BookID = ?";
            PreparedStatement stm = con.prepareStatement(q);
            stm.setString(1, b.getTitle());
            stm.setInt(2, b.getPrice());
            stm.setInt(3, b.getBookID());
            int rs = stm.executeUpdate();
            if (rs > 0) {
                stm.close();
                con.close();
                return true;
            } else {
                stm.close();
                con.close();
                return false;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }

    public boolean delete(int id) {
        try {
            Connection con = getConnection();
            String q = "DELETE FROM Books WHERE BookID = ?";
            PreparedStatement stm = con.prepareStatement(q);
            stm.setInt(1, id);
            int rs = stm.executeUpdate();
            if (rs > 0) {
                stm.close();
                con.close();
                return true;
            } else {
                stm.close();
                con.close();
                return false;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }
7. Tạo index.jsp và thêm đoạn sau:
	<h1>Book Index</h1>
	<div><a href="ControllerServlet?action=add">Add new Book</a></div>
	<br/>
	<table border="1" style="margin-top: 5px">
		<thead>
			<tr>
				<th>ID</th>
				<th>Tittle</th>
				<th>Price</th>
				<th colspan="2">Action</th>
			</tr>
		</thead>
		<tbody>
		<%
			List<Book> list = (List<Book>)request.getAttribute("books");
			for (Book b : list) {
		%>
			<tr>
				<td><%= b.getBookID() %></td>
				<td><%= b.getTitle()%></td>
				<td><%= b.getPrice()%></td>
				<td><a href="ControllerServlet?action=update&BookID=<%=b.getBookID()%>">Update</a></td>
				<td><a href="ControllerServlet?action=delete&BookID=<%=b.getBookID()%>" onclick="return confirm('Are you sure to delete this?')">Delete</a></td>
			</tr>
		<%
			}
		%>
		</tbody>
	</table>