JavaBean 是普通的Java类，也被称为POJO（Plain Ordinary Java Object） JavaBean要求必须是一个公共类（public），必须有一个公共的，无参的构造方法，属性必须是私有的，只能通过共有的方法进行操作
查询图书功能 查询页面：
<form action="bookSelect" method="post"> 书名:<input type="text" name="bookName"/><br/> <input type="submit" value="查询"/> </form>servlet页面
import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class BookSelectServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //设置编码 request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); response.setContentType("text/html"); //获取参数 String bookName = request.getParameter("bookName"); //响应 Book book = BookSelect.book(bookName); request.setAttribute("book", book); request.getRequestDispatcher("bookInfo.jsp").forward(request, response); } }查询页面
import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; public class BookSelect { /** * @param args */ public static Book book(String bookName) { Connection conn = DBUtil.getConn(); String sql = "select * from books where book_name = ?"; Book book = null; try { PreparedStatement ps = conn.prepareStatement(sql); ps.setString(1, bookName); ResultSet rs = ps.executeQuery(); while (rs.next()) { int id = rs.getInt("id"); String name = rs.getString("book_name"); String writer = rs.getString("writer"); float price = rs.getFloat("price"); int code = rs.getInt("code"); book = new Book(id, name, writer, price, code); } } catch (SQLException e) { e.printStackTrace(); } return book; } }返回页面
<% request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); Book book = (Book) request.getAttribute("book"); %> <tr><td>序号</td> <td>书名</td> <td>作者</td> <td>条码</td> <td>价格</td> </tr> <tr> <td><%=book.getId()%></td> <td><%=book.getBookName()%></td> <td><%=book.getWriter()%></td> <td><%=book.getCode()%></td> <td><%=book.getPrice()%></td> </tr>图书查询功能先通过查询页面 获取到参数然后传递给servlet页面，然后在servlet中调用查询，然后查询页中查到的数据返回到servlet中，servlet再传递给展示页面。 jsp标准动作 jsp:useBean</jsp:useBean>
<jsp:useBean id="book2" class="ink.yanglinchao.model.Book" scope="request"></jsp:useBean> <td><jsp:getProperty property="id" name = book /></td><br/> <td><jsp:getProperty property="bookName" name = book /></td><br/> <td><jsp:getProperty property="writer" name = book /></td><br/> <td><jsp:getProperty property="code" name = book /></td><br/> <td><jsp:getProperty property="price" name = book /></td><br/><jsp:include page=“top.jsp”></jsp:include> 页面链接使用
<jsp:forwoad page = “login,jsp”> <jsp:parm value="" name = “”/> <jsp:parm value="" name = “”/> </jsp:forwoad> 相当于转发
