簡單的登陸連接數據庫進行JavaScript 驗證）
方法與步驟：
1.建立一個與數據庫相對應的實體類（pojo）User
2.建立一個與數據庫相連的DAO類DataBaseDAO
3.建立一個從數據庫管理數據庫數據的類UserDAO
4.實體類是一個包，與數據庫相關的是一個包
①．建立登陸頁面
<html>
<head>
<title>登錄界面</title>
</head>
<body>
<form action="checklogin.jsp" method="post" onsubmit="return validate()">
<table align="center" border="1">
<tr>
<td align="right">用戶名：</td>
<td><input type="text" name="username" id="username" value=""/>
</td>
</tr>
<tr>
<td align="right">密碼：</td>
<td><input type="password" name="password" id="password" value=""/></td>
</tr>
<tr>
<td colspan="2" align="center">
<input type="submit" value="登錄"/>
<a href="zhuce.jsp"><input type="button" value="註冊"/></a>
</td>
</tr>
</table>
</form>
</body>
</html>
②．建立檢查用戶和密碼的頁面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="com.anbo.test.dao.*,com.anbo.test.pojo.*"%>
<%
String name = request.getParameter("username");
name = new String(name.getBytes("iso-8859-1"),"utf-8");
String pwd = request.getParameter("password");
UserDAO ud = new UserDAO();
User u = ud.getUser(name,pwd);
if(u!=null){
response.sendRedirect("success.jsp");
}else{
out.println("<script>alert('用戶名或者密碼不正確，請登錄或者註冊');location.href='login.jsp';</script>");
}
%>
③．建立註冊頁面
<body>
<form action="checkzhuce.jsp" method="post" onsubmit="return validate()">
<table align="center" border="1">
<tr>
<td align="right">用戶名：</td>
<td><input type="text" name="username" id="username" value="" />
</td>
</tr>
<tr>
<td align="right">密碼：</td>
<td><input type="password" name="password" id="password" value=""/></td>
</tr>
<tr>
<td align="right">確認密碼：</td>
<td><input type="password" name="newpwd" id="newpwd" value=""/></td>
</tr>
<tr>
<td colspan="2" align="center">
<input type="submit" value="註冊"/>
<input type="reset" value="重置"/>
</td>
</tr>
</table>
</form>
</body>
④．建立檢查註冊頁面，並把數據添加到數據庫
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="com.anbo.test.dao.*,com.anbo.test.pojo.*"%>
<%
String name = request.getParameter("username");
name = new String(name.getBytes("iso-8859-1"),"utf-8");
String pwd = request.getParameter("password");
String newpwd = request.getParameter("newpwd");
UserDAO ud = new UserDAO();
if(ud.addUser(name,pwd)){
out.println("<script>alert('註冊成功！');location.href='success.jsp';</script>");
}else{
out.println("<script>alert('註冊失敗！');location.href='zhuce.jsp';</script>");
}
%>
⑤．登陸成功頁面
成功登陸！
注：客戶端驗證（javaScript）
1.檢查註冊
<script type="text/javascript">
function validatename(){
var text=document.getElementById('username').value;
//if(text==null||text==''){
//不爲空和輸入的不是空格
if(text==null||text.replace(/^\s+,""/).replace(/^\s+$/,"")==''){
alert('用戶名不能爲空！');
//重新獲得焦點
document.getElementById('username').focus();
return false;
}
return true;
}
function validatepwd(){
var pwd=document.getElementById("password").value;
var newpwd=document.getElementById("newpwd").value;
if(pwd==""||pwd.replace(/^\s+,""/).replace(/^\s+$/,"")==''){
alert('密碼不能爲空！');
document.getElementById("password").focus();
return false;
}
if(newpwd==""||newpwd.replace(/^\s+,""/).replace(/^\s+$/,"")==''){
alert('密碼不能爲空！');
document.getElementById("newpwd").focus();
return false;
}
if(pwd!=newpwd){
alert('密碼不相等！請重新錄入');
return false;
}
return true;
}
function validate(){
//注意他的邏輯關係當輸入的爲數字是返回的是false
var flag=validatename();
if(flag==false){
return false;
}
var flag=validatepwd();
if(flag==false){
return false;
}
return true;
}
</script>
2.檢查登陸用戶名和密碼不能爲空
<script type="text/javascript">
function validatename(){
var text=document.getElementById('username').value;
//if(text==null||text==''){
//不爲空和輸入的不是空格
if(text==null||text.replace(/^\s+,""/).replace(/^\s+$/,"")==''){
alert('用戶名不能爲空！');
//重新獲得焦點
document.getElementById('username').focus();
return false;
}
return true;
}
function validatepwd(){
var pwd=document.getElementById("userpwd").value;
if(pwd==""||pwd.replace(/^\s+,""/).replace(/^\s+$/,"")==''){
alert('密碼不能爲空！');
document.getElementById("userpwd").focus();
return false;
}
return true;
}
function validate(){
//注意他的邏輯關係當輸入的爲數字是返回的是false
var flag=validatename();
if(flag==false){
return false;
}
var flag=validatepwd();
if(flag==false){
return false;
}
return true;
}
</script>
⑥．連接數據庫的DAO類DataBaseDAO
package com.anbo.test.dao;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class DataBaseDAO {
private String driver="com.mysql.jdbc.Driver";
private String url="jdbc:mysql://localhost:3306/myuser";
private String name = "root";
private String pwd="root";
Connection conn=null;
//建立與數據庫的連接
public DataBaseDAO(){
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, name,pwd);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//關閉與數據庫的連接
public void CloseConn(){
try {
if(conn!=null){
conn.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//建立執行sql語句的對象並返回影響的行數
public int executeUpdate(String sql){
Statement stmt;
try {
stmt = this.conn.createStatement();
int rows = stmt.executeUpdate(sql);
return rows;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return 0;
}
//創建返回結果集的對象
public ResultSet executeQuery(String sql){
ResultSet rs;
Statement stmt;
try {
stmt = this.conn.createStatement();
rs = stmt.executeQuery(sql);
return rs;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
//將數據插入到數據庫
public int executeUpdate(String sql,Object[] p){
PreparedStatement pstmt;
try {
pstmt = this.conn.prepareStatement(sql);
int i=1;
for(Object o:p){
pstmt.setObject(i, o);
i++;
}
int rows = pstmt.executeUpdate();
return rows;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return 0;
}
}
⑦．創建管理數據庫的UserDAO類
package com.anbo.test.dao;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.anbo.test.pojo.User;
public class UserDAO {
//根據輸入的數據從庫總查詢值，可以沒有這個方法
public boolean checkuser(String name,String pwd){
String sql="select * from login where uname='"+name+"'and upwd='"+pwd+"'";
DataBaseDAO db = new DataBaseDAO();
ResultSet rs;
rs = db.executeQuery(sql);
try {
while(rs.next()){
return true;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally{
db.CloseConn();
}
return false;
}
//判斷用戶是存在
public User getUser(String name,String pwd){
String sql="select * from login where uname='"+name+"'and upwd='"+pwd+"'";
DataBaseDAO db = new DataBaseDAO();
ResultSet rs=null;
User user=null;
rs = db.executeQuery(sql);
try {
while(rs.next()){
int id =rs.getInt(1);
String uname = rs.getString(2);
String upwd = rs.getString(3);
user = new User(id,uname,upwd);
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally{
db.CloseConn();
}
return user;
}
//添加用戶信息
public boolean addUser(String name,String pwd){
String sql="insert into login(uname,upwd) values(?,?)";
DataBaseDAO db = new DataBaseDAO();
Object[] pram={name,pwd};
int rows = db.executeUpdate(sql,pram);
if(rows>0){
return true;
}else{
return false;
}
}
}
⑧．創建User實體類
package com.anbo.test.pojo;
public class User {
private int id;
private String username;
private String password;
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 User(int id, String username, String password) {
super();
this.id = id;
this.username = username;
this.password = password;
}
public User() {
super();
}
}