本案例頁面如下：
這是index.jsp頁面（包含模糊查詢）
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ page import=" java.sql.* "%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>首頁</title> </head> <body> <% //取查詢的名字 String selectName = request.getParameter("txtSelect"); %> <form action="index.jsp"> <h3 align='center'> 請輸入要查詢的的名字：<input type="text" name="txtSelect" value="<%=selectName==null?"":selectName%>"> <input type="submit" name="btnSelect" value="開始查詢"> </h3> </form> <table border="1" width="80%" align='center'> <tr> <td></td> <td>序號</td> <td>姓名</td> <td>性別</td> <td>出生日期</td> <td>操作</td> </tr> <% //連接數據庫的五大參數 String driverClass = "com.mysql.cj.jdbc.Driver"; String serverIp = "localhost"; String databaseName = "test3"; String userName = "root"; String pwd = "123456"; String jdbcUrl = "jdbc:mysql://"+serverIp+":3306/"+databaseName+"?serverTimezone=Asia/Shanghai&useSSL=true"; String sql = "select * from test3"; //讀取JDBC Class.forName(driverClass); //鏈接數據庫 Connection con = DriverManager.getConnection(jdbcUrl,userName,pwd); //如果為空，代表當前的狀態不是查詢，而是查詢所有的內容 PreparedStatement ps ; if(selectName == null){ //判斷查詢文本框里面是否有內容，如果沒有則執行查詢全部信息 ps = con.prepareStatement(sql); }else{ //如果有，則根據文本框的里面的內容在數據庫根據姓名查詢 ps = con.prepareStatement("select * from test3 where user_name like ?"); ps.setString(1,'%'+selectName+'%'); } //ResultSet是一個指向數據庫的變量，本質上是不保存任何數據的，執行查詢 ResultSet rs = ps.executeQuery(); //boolean flag = rs.next(); //判斷返回指針是否還能繼續往下移動 //顯示序號 int i = 1; while( rs.next()){ %> <tr> <td><%out.print(i++);%></td> <td><%=rs.getString("id") %></td> <td><%=rs.getString("user_name")%></td> <td><%=rs.getString("sex")%></td> <td><%=rs.getString("birt") %></td> <td> <a href="insert_Jsp.jsp">添加</a> <a href="editView.jsp?id=<%=rs.getString("id")%> ">編輯</a> <a href="delete_action.jsp?id=<%=rs.getString("id")%>">刪除</a> </td> </tr> <% } %> </table> <h1 align="center">共計<%=i-1%>條記錄</h1> <% ps.close(); con.close(); %> </body> </html>
這是刪除邏輯頁面：delete_action.jsp（后台運行，不顯示）
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@page import="java.sql.*" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>刪除的業務邏輯執行頁面</title> </head> <body> <% //獲取參數 String id = request.getParameter("id"); //連接數據庫的五大參數 String driverClass = "com.mysql.cj.jdbc.Driver"; String serverIp = "localhost"; String databaseName ="test3"; String user = "root"; String pwd = "123456"; //拼湊成一個完整的Url地址 String jdbcUrl ="jdbc.mysql://"+serverIp+":3306/"+databaseName+"?serverTimezone=Asia/Shanghai%useSSL=true"; //創建對象 Connection con = DriverManager.getConnection(jdbcUrl,user,pwd); String sql = "delete from test3 where id = ?"; PreparedStatement ps = con.prepareStatement(sql); //對應sql語句的問號跟上面從頁面獲取的參數相對應 ps.setObject(1,id); //執行刪除 ps.executeUpdate(); //關閉連接 ps.close(); con.close(); //完成刪除后跳轉回index頁面 response.sendRedirect("index.jsp"); %> </body> </html>
這是用於添加的業務邏輯的運算：index_action.jsp（不顯示，后台運算）
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@page import = "java.sql.*" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>添加</title> </head> <body> <% //獲取參數 String name = request.getParameter("txtName"); String sex = request.getParameter("txtSex"); String birt = request.getParameter("txtBirthday"); //連接數據庫的五大參數 String driverClass = "com.mysql.cj.jdbc.Driver"; String serverIp = "localhost"; String databaseName = "test3"; String userName = "root"; String pwd = "123456"; String jdbcUrl = "jdbc:mysql://"+serverIp+":3306/"+databaseName+"?serverTimezone=Asia/Shanghai&useSSL=true"; Class.forName(driverClass); Connection con = DriverManager.getConnection(jdbcUrl,userName,pwd); String sql ="insert into test3(user_name,sex,birt) values(?,?,?)"; PreparedStatement ps = con.prepareStatement(sql); ps.setString(1,name); ps.setString(2,sex); ps.setString(3,birt); ps.executeUpdate(); con.close(); response.sendRedirect("index.jsp"); %> </body> </html>
這是添加的顯示頁面：index.jsp（用戶客戶端） <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>添加信息</title> </head> <body> <% %> <form action="insert.jsp"> 學號：<input type="text" name="txtId" ><br> 姓名：<input type="text" name="txtName"><br> 性別：<input type="text" name="txtSex"><br> 出生年月日：<input type="text" name="txtBirthday"><br> <input type="submit" value="確認添加"> </form> </body> </html>
修改的業務邏輯運算界面：update_action.jsp（不顯示，后台執行）
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ page import="java.sql.*" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>編輯業務邏輯頁面</title> </head> <body> <% //獲取參數 String id = request.getParameter("txtId"); String name = request.getParameter("txtUser"); String sex = request.getParameter("selSex"); String birt = request.getParameter("txtBirthday"); //連接數據庫的五大參數 String driverClass = "com.mysql.cj.jdbc.Driver"; String serverIp = "localhost"; String databaseName = "test3"; String userName = "root"; String pwd = "123456"; //整合連接地址 String jdbcUrl = "jdbc:mysql://"+serverIp+":3306/"+databaseName+"?serverTimezone=Asia/Shanghai&useSSL=true"; Class.forName(driverClass); Connection con = DriverManager.getConnection(jdbcUrl,userName,pwd); //要執行的SQL語句 String sql ="update test3 set user_name=?,sex=?,birt=? where id=?"; PreparedStatement ps = con.prepareStatement(sql); ps.setString(1,name); ps.setString(2,sex); ps.setString(3,birt); ps.setObject(4,id); //執行修改 ps.execute(); ps.close(); con.close(); response.sendRedirect("index.jsp"); %> </body> </html>
修改的顯示界面：editView（由客戶端進行操作的顯示頁面）
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ page import="java.sql.*" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>老師講解的修改</title> </head> <body> <% //獲取參數 String id = request.getParameter("id"); //連接數據庫的五大參數 String driverClass = "com.mysql.jdbc.Driver"; String databaseName = "test3"; String serverIP = "localhost"; String user = "root"; String pwd = "123456"; //拼湊成一個完整的Url地址 String jdbcUrl = "jdbc:mysql://"+serverIP+":3306/"+databaseName+"?serverTimezone=Asia/Shanghai&useSSL=true"; Class.forName(driverClass); Connection con = DriverManager.getConnection(jdbcUrl,user,pwd); String sql = "select * from test3 where id = ?"; //創建對象 PreparedStatement ps = con.prepareStatement(sql); //將字符串的id轉換成int型的id ps.setObject(1, id); ResultSet rs= ps.executeQuery(); if(rs.next()){ %> <form action="update_action.jsp" > <input type="hidden" name="txtId" value="<%=rs.getString("id") %>"> 姓名：<input type ="text" name="txtUser" value="<%=rs.getString("user_name")%>"><br> 性別： <select name="selSex"> <option value="男" <%if(rs.getString("sex").equals("男")){out.print("selected");} %> >男</option> <option value="女" <%if(rs.getString("sex").equals("女")){out.print("selected");} %>>女</option> <option value="其他" <%if(rs.getString("sex").equals("其他")){out.print("selected");} %>>其他</option> </select><br> 出生日期：<input type ="text" name="txtBirthday" value="<%=rs.getString("birt") %>"><br> <input type="submit" value="確認更新" name="btnsub"> </form> <% }else{ response.sendRedirect("error.jsp"); } rs.close(); ps.close(); con.close(); %> </body> </html>
最后選擇整個項目，右鍵選擇Run As --> Run on Server 運行整個項目，然后將地址欄復制，在瀏覽器的地址欄粘貼，加上/index.jsp運行
