jsp 实现修改和删除功能
main.jsp 实现查询 在此界面快捷方式到修改界面
点击修改 会把数据传递到exit.jsp
修改 edit.jsp
前面数据：
数据库：
/*
Navicat Premium Data Transfer Source Server : c10.87.12.251
Source Server Type : SQL Server
Source Server Version : 11002100
Source Host : 10.87.12.251:1433
Source Catalog : userdb
Source Schema : dbo Target Server Type : SQL Server
Target Server Version : 11002100
File Encoding : 65001 Date: 19/06/2019 22:19:40
*/ -- ----------------------------
-- Table structure for userinfo
-- ----------------------------
IF EXISTS (SELECT * FROM sys.all_objects WHERE object_id = OBJECT_ID(N'[dbo].[userinfo]') AND type IN ('U'))
DROP TABLE [dbo].[userinfo]
GO CREATE TABLE [dbo].[userinfo] (
[id] int IDENTITY(1,1) NOT NULL,
[username] varchar(50) COLLATE Chinese_PRC_CI_AS NULL,
[userpwd] varchar(50) COLLATE Chinese_PRC_CI_AS NULL,
[sex] varchar(50) COLLATE Chinese_PRC_CI_AS NULL,
[age] int NULL,
[address] varchar(50) COLLATE Chinese_PRC_CI_AS NULL
)
GO ALTER TABLE [dbo].[userinfo] SET (LOCK_ESCALATION = TABLE)
GO -- ----------------------------
-- Records of [userinfo]
-- ----------------------------
SET IDENTITY_INSERT [dbo].[userinfo] ON
GO INSERT INTO [dbo].[userinfo] ([id], [username], [userpwd], [sex], [age], [address]) VALUES (N'', N'root', N'', N'', N'', N'')
GO SET IDENTITY_INSERT [dbo].[userinfo] OFF
GO
用户信息数据库代码
（1）db/DbConn.java
package db; import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement; public class DbConn { public static Connection getConn()
{
Connection con =null;
try {
// Class.forName("com.mysql.jdbc.Driver"); // 加载驱动程序
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); } catch (ClassNotFoundException e) {
System.out.println("加载驱动程序错误" + e.getMessage());
} try {
// 创建连接 testdb是数据库名称
con = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;DatabaseName=userdb", "sa", "123456"); } catch (SQLException e) { System.out.println("数据库连接操作出错" + e.getMessage());
}
return con;
}
}
l连接数据库代码
（2） po/User.java
package po;
public class User {
int id;
String username;
String password;
int age;
String sex;
String address;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
交互相关字段
（3） dao/UserDAO.java
//根据id 查找字段 返回给edit表
public User getUser(int id)
{
User u=new User();
try {
// 创建连接 testdb是数据库名称
Connection con =DbConn.getConn();
// 创建声明SQL对象
Statement stm = con.createStatement();
// 执行SQL语句，得到结果集，结果集放到ResultSet对象中
ResultSet rs = stm.executeQuery("select * from userinfo where id="+id);
// 通过循环，从结果集对象中取得数据
while (rs.next()) { String username = rs.getString("username"); // 取得字符类型的字段username的值，
String userpwd = rs.getString("userpwd");
String sex=rs.getString("sex");
int age=rs.getInt("age");
String address=rs.getString("address"); u.setId(id);
u.setUsername(username);
u.setPassword(userpwd);
u.setSex(sex);
u.setAge(age);
u.setAddress(address); }
} catch (SQLException e) { System.out.println("数据库操作出错" + e.getMessage());
}
return u;
}
//插入新数据 根据id
public int edit(User u)
{
int n=0;
try {
// 创建连接 testdb是数据库名称
Connection con = DbConn.getConn(); // 创建声明SQL对象
Statement stm = con.createStatement();
// 执行SQL语句，得到结果集，结果集放到ResultSet对象中
String sql="update userinfo set username='"+u.getUsername()+"',userpwd='"+u.getPassword()+"',sex='"+u.getSex()+"',age="+u.getAge()+",address='"+u.getAddress()+"' " +
"where id="+u.getId()+"";
n=stm.executeUpdate(sql);
} catch (SQLException e) { System.out.println("数据库操作出错" + e.getMessage());
}
return n;
}
根据id 查找字段返回给edit表和插入数据
public List<User> getUserList()
{
List<User> ls=new ArrayList<User>();
try {
// 创建连接 testdb是数据库名称
Connection con =DbConn.getConn();
// 创建声明SQL对象
Statement stm = con.createStatement();
// 执行SQL语句，得到结果集，结果集放到ResultSet对象中
ResultSet rs = stm.executeQuery("select * from userinfo");
// 通过循环，从结果集对象中取得数据
while (rs.next()) {
int id = rs.getInt("id"); // 取得int类型的字段id的值，
String username = rs.getString("username"); // 取得字符类型的字段username的值，
String userpwd = rs.getString("userpwd");
String sex=rs.getString("sex");
int age=rs.getInt("age");
String address=rs.getString("address");
User u=new User();
u.setId(id);
u.setUsername(username);
u.setPassword(userpwd);
u.setSex(sex);
u.setAge(age);
u.setAddress(address);
ls.add(u);
}
} catch (SQLException e) { System.out.println("数据库操作出错" + e.getMessage());
}
return ls;
}
查询所有信息
public boolean login(String username,String userpwd)
{
boolean flag=false;
try {
// 创建连接 testdb是数据库名称
Connection con = DbConn.getConn();
// 创建声明SQL对象
Statement stm = con.createStatement();
// 执行SQL语句，得到结果集，结果集放到ResultSet对象中
ResultSet rs = stm.executeQuery("select * from userinfo where username='"+username+"' and userpwd='"+userpwd+"' ");
// 通过循环，从结果集对象中取得数据
if(rs.next()) {
flag=true;
}
else
{
flag=false;
} } catch (SQLException e) { System.out.println("数据库操作出错" + e.getMessage());
}
return flag;
}
login 验证
（4）servlet
main里面的 <td><a href="servlet/GetUserServlet?userid=<%=u.getId()%>">修改</a></td> 调用 GetUserServlet 调用UserDAO. getUser(int id) 方法
GetUserServlet.java
package servlet; import java.io.IOException;
import java.io.PrintWriter;
import java.util.List; import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession; import po.User;
import dao.UserDAO; public class GetUserServlet extends HttpServlet { /**
* Constructor of the object.
*/
public GetUserServlet() {
super();
} /**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
} /**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
} /**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>"); //根据id 查找到所有字段返回给exit.jsp HttpSession session=request.getSession(true);
String sid=request.getParameter("userid");
int id=Integer.parseInt(sid);
UserDAO udao=new UserDAO();
User u= udao.getUser(id);
//传递给session 对象
session.setAttribute("user", u);
response.sendRedirect("../edit.jsp"); out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
} /**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
} }
根据id 查找到所有字段返回给exit.jsp
edit.jsp 修改好后的传递给
EditServlet.java
package servlet; 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; import po.User;
import dao.UserDAO; public class EditServlet extends HttpServlet { /**
* Constructor of the object.
*/
public EditServlet() {
super();
} /**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
} /**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { doPost(request,response);
} /**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
//获取edit 传递的字段 String userid=request.getParameter("userid");
String username=request.getParameter("username");
String userpwd=request.getParameter("userpwd");
String sex=request.getParameter("sex");
String age=request.getParameter("age");
String address=request.getParameter("address"); User u=new User();
u.setId(Integer.parseInt(userid));
u.setUsername(username);
u.setPassword(userpwd);
u.setSex(sex);
u.setAge(Integer.parseInt(age));
u.setAddress(address); //调用方法
UserDAO udao=new UserDAO(); int n=udao.edit(u);
if(n>0) {
//成功就调用查询方法 看修改完后的
response.sendRedirect("../servlet/GetUsersServlet");
}
else
{
out.println("修改失败");
} out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
} /**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
} }
从edit.jsp获取数据在调用修改函数 给数据库
login.jsp 调用
package servlet; import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*; import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse; import dao.UserDAO;
import db.DbConn; public class LoginServlet extends HttpServlet { /**
* Constructor of the object.
*/
public LoginServlet() {
super();
} /**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
} /**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
} /**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>"); String username=(String)request.getParameter("username");
String userpwd=(String)request.getParameter("password"); UserDAO udao=new UserDAO();
boolean flag= udao.login(username, userpwd); if(flag==true){
out.print("success"); response.sendRedirect("../servlet/GetUsersServlet"); }
else
out.print("false"); out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
} /**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
} }
LoginServlet.java
查询所有GetUsersServlet.java
package servlet; import java.io.IOException;
import java.io.PrintWriter;
import java.util.List; import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession; import po.User; import dao.UserDAO; public class GetUsersServlet extends HttpServlet { /**
* Constructor of the object.
*/
public GetUsersServlet() {
super();
} /**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
} /**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
} /**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
HttpSession session=request.getSession(true); UserDAO udao=new UserDAO();
List<User> ls= udao.getUserList();
session.setAttribute("userlist", ls);
response.sendRedirect("../main.jsp"); out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
} /**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
} }
获取所有数据
DelServlet.java
package servlet; import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*; import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse; import db.DbConn; public class DelServlet extends HttpServlet { /**
* Constructor of the object.
*/
public DelServlet() {
super();
} /**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
} /**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
} /**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>"); String userid=request.getParameter("userid");
out.println(userid); try {
// 创建连接 testdb是数据库名称
Connection con = DbConn.getConn();
// 创建声明SQL对象
Statement stm = con.createStatement();
// 执行SQL语句，得到结果集，结果集放到ResultSet对象中 int n=stm.executeUpdate(sql);
if(n>0) {
response.sendRedirect("../servlet/GetUsersServlet"); }
else
{
out.println("删除失败");
} } catch (SQLException e) { System.out.println("数据库操作出错" + e.getMessage());
} out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
} /**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
} }
删除
1.main.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="po.*" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'main.jsp' starting page</title>
</head> <body>
<table width="502" border="1">
<tr>
<td width="37">序号</td>
<td width="63">姓名</td>
<td width="52">密码</td>
<td width="52">年龄</td>
<td width="61">性别</td>
<td width="197">地址</td>
<td width="80">删除</td>
<td width="80">修改</td>
</tr>
<% List<User> ls=(List<User>)session.getAttribute("userlist");
for(int i=0;i<ls.size();i++)
{
User u=ls.get(i);
%>
<tr>
<td><%=u.getId()%></td>
<td><%=u.getUsername()%></td>
<td><%=u.getPassword()%></td>
<td><%=u.getAge()%></td>
<td><%=u.getSex()%></td>
<td><%=u.getAddress()%></td>
<td><a href="servlet/DelServlet?userid=<%=u.getId()%>">删除</a></td>
<td><a href="servlet/GetUserServlet?userid=<%=u.getId()%>">修改</a></td>
</tr>
<%
}
%>
</table>
<a href="add.jsp">添加</a>
</body>
</html>
查询界面和修改界面
2.修改 edit.jsp
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%@ page import="po.*" %>
<!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=ISO-8859-1">
<title>Insert title here</title>
</head>
<body> <%
User u=(User)session.getAttribute("user");
%>
<p>用户添加</p>
<form name="frm1" action="servlet/EditServlet">
<p>姓名：
<label for="textfield"></label>
<input type="text" name="username" id="textfield" value="<%=u.getUsername() %>"/>
<input type="hidden" name="userid" id="textfield" value="<%=u.getId() %>"/>
</p>
<p>密码：
<input type="text" name="userpwd" id="textfield2" value="<%= u.getPassword()%>"/>
</p>
<p>年龄：
<input type="text" name="age" id="textfield3" value="<%=u.getAge() %>"/>
</p>
<p>性别：
<input type="text" name="sex" id="textfield4" value="<%=u.getSex() %>"/>
</p>
<p>地址：
<input type="text" name="address" id="textfield5" value="<%=u.getAddress() %>"/>
</p>
<p> </p>
<input type="submit" value="确定"/>
</form>
</body>
</html>
edit.jsp
3.Login
<%@ page language="java" import="java.util.*" pageEncoding="GB2312"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>"> <title>My JSP 'Login.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
--> </head> <body>
<div align="center" >
<form method="get" action="servlet/LoginServlet">
用户名:<input type="text" name="username"><br>
密码：<input type="password" name="password"><br>
<input type="submit" name="button1" value="登录">
</form>
</div>
</body>
</html>
Login.jsp 它调用LoginServle至main.jspt
运行过程
修改的运行过程： Login.jsp--->LoginServlet-->main.jsp-->GetUserServlet->exit.jsp->EditServlet ->main.jsp
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