标签：zone ram resultset tco 老师 复制 url btn dtd
本案例页面如下：
这是index.jsp页面（包含模糊查询）
<%@ 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>首页</title> </head> <body> <% //取查询的名字 String selectName = request.getParameter("txtSelect"); %> <form action="index.jsp"> <h3 align=‘center‘> 请输入要查询的的名字：<input type="text" name="txtSelect" value="<%=selectName==null?"":selectName%>"> <input type="submit" name="btnSelect" value="开始查询"> </h3> </form> <table border="1" width="80%" align=‘center‘> <tr> <td></td> <td>序号</td> <td>姓名</td> <td>性别</td> <td>出生日期</td> <td>操作</td> </tr> <% //连接数据库的五大参数 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"; //读取JDBC Class.forName(driverClass); //链接数据库 Connection con = DriverManager.getConnection(jdbcUrl,userName,pwd); //如果为空，代表当前的状态不是查询，而是查询所有的内容 PreparedStatement ps ; if(selectName == null){ //判断查询文本框里面是否有内容，如果没有则执行查询全部信息 ps = con.prepareStatement(sql); }else{ //如果有，则根据文本框的里面的内容在数据库根据姓名查询 ps = con.prepareStatement("select * from test3 where user_name like ?"); ps.setString(1,‘%‘+selectName+‘%‘); } //ResultSet是一个指向数据库的变量，本质上是不保存任何数据的，执行查询 ResultSet rs = ps.executeQuery(); //boolean flag = rs.next(); //判断返回指针是否还能继续往下移动 //显示序号 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")%> ">编辑</a> <a href="delete_action.jsp?id=<%=rs.getString("id")%>">删除</a> </td> </tr> <% } %> </table> <h1 align="center">共计<%=i-1%>条记录</h1> <% ps.close(); con.close(); %> </body> </html>
这是删除逻辑页面：delete_action.jsp（后台运行，不显示）
<%@ 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>删除的业务逻辑执行页面</title> </head> <body> <% //获取参数 String id = request.getParameter("id"); //连接数据库的五大参数 String driverClass = "com.mysql.cj.jdbc.Driver"; String serverIp = "localhost"; String databaseName ="test3"; String user = "root"; String pwd = "123456"; //拼凑成一个完整的Url地址 String jdbcUrl ="jdbc.mysql://"+serverIp+":3306/"+databaseName+"?serverTimezone=Asia/Shanghai%useSSL=true"; //创建对象 Connection con = DriverManager.getConnection(jdbcUrl,user,pwd); String sql = "delete from test3 where id = ?"; PreparedStatement ps = con.prepareStatement(sql); //对应sql语句的问号跟上面从页面获取的参数相对应 ps.setObject(1,id); //执行删除 ps.executeUpdate(); //关闭连接 ps.close(); con.close(); //完成删除后跳转回index页面 response.sendRedirect("index.jsp"); %> </body> </html>
这是用于添加的业务逻辑的运算：index_action.jsp（不显示，后台运算）
<%@ 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> <% //获取参数 String name = request.getParameter("txtName"); String sex = request.getParameter("txtSex"); String birt = request.getParameter("txtBirthday"); //连接数据库的五大参数 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>
这是添加的显示页面：index.jsp（用户客户端） <%@ 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"> 学号：<input type="text" name="txtId" ><br> 姓名：<input type="text" name="txtName"><br> 性别：<input type="text" name="txtSex"><br> 出生年月日：<input type="text" name="txtBirthday"><br> <input type="submit" value="确认添加"> </form> </body> </html>
修改的业务逻辑运算界面：update_action.jsp（不显示，后台执行）
<%@ 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>编辑业务逻辑页面</title> </head> <body> <% //获取参数 String id = request.getParameter("txtId"); String name = request.getParameter("txtUser"); String sex = request.getParameter("selSex"); String birt = request.getParameter("txtBirthday"); //连接数据库的五大参数 String driverClass = "com.mysql.cj.jdbc.Driver"; String serverIp = "localhost"; String databaseName = "test3"; String userName = "root"; String pwd = "123456"; //整合连接地址 String jdbcUrl = "jdbc:mysql://"+serverIp+":3306/"+databaseName+"?serverTimezone=Asia/Shanghai&useSSL=true"; Class.forName(driverClass); Connection con = DriverManager.getConnection(jdbcUrl,userName,pwd); //要执行的SQL语句 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); //执行修改 ps.execute(); ps.close(); con.close(); response.sendRedirect("index.jsp"); %> </body> </html>
修改的显示界面：editView（由客户端进行操作的显示页面）
<%@ 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>老师讲解的修改</title> </head> <body> <% //获取参数 String id = request.getParameter("id"); //连接数据库的五大参数 String driverClass = "com.mysql.jdbc.Driver"; String databaseName = "test3"; String serverIP = "localhost"; String user = "root"; String pwd = "123456"; //拼凑成一个完整的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 = ?"; //创建对象 PreparedStatement ps = con.prepareStatement(sql); //将字符串的id转换成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> 性别： <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="确认更新" name="btnsub"> </form> <% }else{ response.sendRedirect("error.jsp"); } rs.close(); ps.close(); con.close(); %> </body> </html>
最后选择整个项目，右键选择Run As --> Run on Server 运行整个项目，然后将地址栏复制，在浏览器的地址栏粘贴，加上/index.jsp运行
标签：zone ram resultset tco 老师 复制 url btn dtd
原文地址：https://www.cnblogs.com/liaoyuanping-24/p/9197577.html
