後臺系統的所有界面圖以及之前的準備工作歡迎看我之前的博文>3<
具體的代碼未來將傳到csdn下載或github下載~
有任何問題歡迎下方評論=W=
一、圖片效果
①項目目錄圖1與圖2
②登錄模塊圖
③註冊模塊圖
二、設置字符集過濾器
①Java Resources的src-->建立package,命名爲filter-->創建一個DoFilter的java文件,具體代碼如下
(PS.這個過濾器我也是仿照csdn一個老哥的做的,在此感謝這位老哥>3<)
DoFilter.java文件:
package filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class DoFilter implements Filter {
public DoFilter(){
System.out.println("過濾器構造");
}
public void destroy() {
System.out.println("過濾器銷燬");
}
public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {
request.setCharacterEncoding("utf-8"); //將編碼改爲utf-8
response.setContentType("text/html;charset=utf-8");
chain.doFilter(request, response);
}
public void init(FilterConfig arg0) throws ServletException {
System.out.println("過濾器初始化");
}
}
②在WebContent-->WEB-INF-->web.xml中,設置如下內容
web.xml文件:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
<display-name>MyBlog</display-name>
<filter>
<filter-name>Dofilter</filter-name>
<filter-class>filter.DoFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>Dofilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- 歡迎頁,即進入項目的第一個界面 -->
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
</web-app>
三、EL與JSTL表達式
①先載入JSTL的Jar包,在項目右鍵BuildPath-->Configure Build Path的Libraries裏-->Add Jars-->選擇目標Jar包
②爲確保載入Jar包成功,應該在WebContent-->WEB-INF-->lib的文件夾中查看是否有如下內容,這次用的便是有jstl前綴的jar包
③在WebContent-->新建一個jsp文件,取名爲base.jsp-->寫入如下內容
(關於layui、bootstrap等框架資源百度即可,按照目錄結構放入其中)
base.jsp文件:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<c:set var="ctx" value="${pageContext.request.contextPath}"></c:set>
<link rel="stylesheet" href="${ctx }/js/layui/css/layui.css">
<script src="${ctx }/js/jquery-3.2.1.min.js"></script>
<script src="${ctx }/js/layui/layui.js"></script>
<script src="${ctx}/js/bootstrap/js/bootstrap.min.js"></script>
四、登錄模塊
①邏輯分析(以下爲我畫的管理員登錄業務流程圖)
②詳細的數據庫之前的博文已經寫了,爲了更好閱讀這裏再寫一次
建數據庫,命名爲blog-->建表,命名爲dai_adm,設計表的字段如下
屬性名 |
類型 |
長度 |
允許空 |
是否主鍵 |
說明 |
adm_id |
tinyint |
4 |
NOT NULL |
主鍵 |
管理員id、自增 |
adm_name |
varchar |
20 |
NOT NULL |
|
管理員名稱 |
adm_password |
varchar |
20 |
NOT NULL |
|
管理員密碼 |
③既然是登錄,自然要與數據庫進行對接,這裏我使用的是mysql數據庫,要求要加載好mysql的jar包,步驟同之前JSTL的Jar包設置步驟
3.1 在Java Resources的src下-->新建package,命名爲util-->新建一個config.properties文件,內容如下
(由於我mysql是接入3306端口,數據庫連接時使用的用戶名是root,沒有設置密碼,所以這麼設置,如果你有密碼,pwd=你的密碼)
config.properties文件:
driverClass=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/blog?useUnicode=true&characterEncoding=utf-8&useSSL=false
#mysql username
user=root
#mysql password
pwd=
3.2 在Java Resources的src下-->util包中-->新建一個class文件,命名爲DBUtil,代碼如下
DBUtil.java文件:
package util;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
public class DBUtil {
private static String driverClass;
private static String url;
private static String user;
private static String pwd;
//static block靜態塊
static{
//產生properties類的實例
Properties prop = new Properties();
//轉換成文件流
InputStream is = DBUtil.class.getClassLoader().getResourceAsStream("util/config.properties");
try {
prop.load(is);
driverClass = prop.getProperty("driverClass").trim();
url = prop.getProperty("url").trim();
user = prop.getProperty("user").trim();
pwd = prop.getProperty("pwd").trim();
Class.forName(driverClass);
//當前類的位置
System.out.println(DBUtil.class.getResource(""));
//當前類的根目錄的位置
System.out.println(DBUtil.class.getClassLoader().getResource(""));
} catch (Exception e) {
e.printStackTrace();
}
}
public static Connection getConnection(){
// 數據庫的連接
Connection conn = null;
try {
conn = DriverManager.getConnection(url, user,pwd);
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
public static void closeConnection(Connection conn) throws SQLException {
conn.close();
}
}
④這個項目使用了MVC結構,登錄模塊也就是對管理員進行操作,這裏先寫pojo層,再寫dao層
4.1 在src中-->新建一個package,命名爲pojo-->新建一個class文件,命名爲Adm,內容如下
Adm.java文件:
package pojo;
public class Adm{
private Integer adm_id;
private String adm_name;
private String adm_password;
public Integer getAdm_id() {
return adm_id;
}
public void setAdm_id(Integer adm_id) {
this.adm_id = adm_id;
}
public String getAdm_name() {
return adm_name;
}
public void setAdm_name(String adm_name) {
this.adm_name = adm_name;
}
public String getAdm_passward() {
return adm_password;
}
public void setAdm_passward(String adm_password) {
this.adm_password = adm_password;
}
}
4.2 由於後來要做分頁功能,所以還要封裝一個類-->pojo包中-->新建一個class,命名爲ChangePage,內容如下
ChangePage.java文件:
package pojo;
public class ChangePage {
private int page; //默認第一頁
private int limit; //默認一頁10條數據
private int startRow = (page-1)*limit;//mysql里語句隨之發生改變
private String sort;//排序字段
private String order;//排序關鍵字
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public int getLimit() {
return limit;
}
public void setLimit(int limit) {
this.limit = limit;
}
public int getStartRow() {
return (page-1)*limit;
}
public void setStartRow(int startRow) {
this.startRow = startRow;
}
public String getSort() {
return sort;
}
public void setSort(String sort) {
this.sort = sort;
}
public String getOrder() {
return order;
}
public void setOrder(String order) {
this.order = order;
}
}
4.3 在src中-->新建一個package,命名爲dao-->新建一個interface文件,命名爲AdmDao,內容如下
AdmDao.java文件:
package dao;
import java.util.ArrayList;
import pojo.Adm;
public interface AdmDao {
//1.查詢管理員,返回一個管理員類型 這是login裏頭的方法
public Adm getAdm(String username,String password);
//2查詢所有的管理員
public ArrayList<Adm> getAllAdm();
//3.添加管理員
public boolean insertAdm(String username,String pwd);
//4.根據id刪除管理員
public boolean deleteAdm(int id);
//5.修改管理員信息
public boolean updateAdm(Adm a);
//6.根據adm_name查詢是否存在該用戶,即id唯一,用戶名唯一
public boolean queryIsExist(String username);
//7.根據id,查詢一個管理員
public Adm getOneAdm(int adm_id);
//8 分頁查詢所有的管理員
public ArrayList<Adm> getPageAdm(int page,int limit);
}
4.4 寫AdmDao的實現類,本應該放在不同的包裏,我當時爲了簡便,依然放在了dao包
dao包-->新建class文件,命名爲AdmDaoImpl-->實現AdmDao接口,代碼如下
AdmDaoImpl.java文件:
package dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import pojo.Adm;
import pojo.ChangePage;
import util.DBUtil;
public class AdmDaoImpl implements AdmDao {
// 分頁方法
@Override
public ArrayList<Adm> getPageAdm(int page, int limit) {
ArrayList<Adm> adm = new ArrayList<Adm>();
Connection conn = DBUtil.getConnection();
ChangePage cp = new ChangePage();
cp.setLimit(limit);
cp.setPage(page);
int startRow = cp.getStartRow();
String sql = "select * from dai_adm limit " + startRow + "," + limit + "";
// 預編譯
try {
PreparedStatement prep = conn.prepareStatement(sql);
ResultSet rst = prep.executeQuery();
while (rst.next()) {
Adm ad = new Adm();
ad.setAdm_id(rst.getInt(1));
ad.setAdm_name(rst.getString("adm_name"));
ad.setAdm_passward(rst.getString("adm_password"));
adm.add(ad);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closeConnection(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
return adm;
}
// 查詢所有的管理員
@Override
public ArrayList<Adm> getAllAdm() {
ArrayList<Adm> adm = new ArrayList<Adm>();
Connection conn = DBUtil.getConnection();
// 在數據庫中添加記錄
String sql = "select * from dai_adm";
// 預編譯
try {
PreparedStatement prep = conn.prepareStatement(sql);
ResultSet rst = prep.executeQuery();
while (rst.next()) {
Adm ad = new Adm();
ad.setAdm_id(rst.getInt(1));
ad.setAdm_name(rst.getString("adm_name"));
ad.setAdm_passward(rst.getString("adm_password"));
adm.add(ad);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closeConnection(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
return adm;
}
@Override
public Adm getAdm(String username, String password) {
Adm a = null;
Connection conn = DBUtil.getConnection();
String sql = "select * from dai_adm where adm_name = ? and adm_password = ?";
// 預編譯
PreparedStatement prep;
try {
prep = conn.prepareStatement(sql);
prep.setString(1, username);
prep.setString(2, password);
ResultSet rst = prep.executeQuery();
if (rst.next()) {
System.out.println("啊啊啊,我是servlet,我已經查到信息了!!!");
a = new Adm();
a.setAdm_id(rst.getInt("adm_id"));
a.setAdm_name(rst.getString("adm_name"));
a.setAdm_passward(rst.getString("adm_password"));
return a;
} else {
// System.out.println(username+","+password);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
DBUtil.closeConnection(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
return a;
}
// 3.添加管理員
@Override
public boolean insertAdm(String username, String pwd) {
Connection conn = DBUtil.getConnection();
// 在數據庫中添加記錄
String sql = "insert into dai_adm(adm_name,adm_password) values(?,?)";
// 預編譯
PreparedStatement prep;
try {
prep = conn.prepareStatement(sql);
prep.setString(1, username);
prep.setString(2, pwd);
prep.executeUpdate();
return true;
} catch (SQLException e) {
e.printStackTrace();
return false;
} finally {
try {
DBUtil.closeConnection(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
@Override
public boolean deleteAdm(int adm_id) {
Connection conn = DBUtil.getConnection();
// 在數據庫中刪除記錄
String sql = "delete from dai_adm where adm_id = ?";
// 預編譯
PreparedStatement prep;
try {
prep = conn.prepareStatement(sql);
prep.setInt(1, adm_id);
prep.executeUpdate();
return true;
} catch (SQLException e) {
e.printStackTrace();
return false;
} finally {
try {
DBUtil.closeConnection(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
@Override
public boolean updateAdm(Adm a) {
Connection conn = DBUtil.getConnection();
// 在數據庫中修改記錄
String sql = "update dai_adm set adm_name = ?,adm_password = ? where adm_id=?";
// 預編譯
PreparedStatement prep;
try {
prep = conn.prepareStatement(sql);
prep.setString(1, a.getAdm_name());
prep.setString(2, a.getAdm_passward());
prep.setInt(3, a.getAdm_id());
prep.executeUpdate();
return true;
} catch (SQLException e) {
e.printStackTrace();
return false;
} finally {
try {
DBUtil.closeConnection(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
@Override
public boolean queryIsExist(String username) {
Connection conn = DBUtil.getConnection();
// 在數據庫中查詢記錄
String sql = "select * from dai_adm where adm_name = ?";
// 預編譯
PreparedStatement prep;
try {
prep = conn.prepareStatement(sql);
prep.setString(1, username);
ResultSet rst = prep.executeQuery();
if (rst.next()) {
return true;
} else {
return false;
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
DBUtil.closeConnection(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
return false;
}
@Override
public Adm getOneAdm(int adm_id) {
Adm a = null;
Connection conn = DBUtil.getConnection();
// 在數據庫中修改記錄
String sql = "select * from dai_adm where adm_id = ?";
// 預編譯
PreparedStatement prep;
try {
prep = conn.prepareStatement(sql);
prep.setInt(1, adm_id);
ResultSet rst = prep.executeQuery();
a = new Adm();
if (rst.next()) {
a.setAdm_id(rst.getInt(1));
a.setAdm_name(rst.getString("adm_name"));
a.setAdm_passward(rst.getString("adm_password"));
return a;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
DBUtil.closeConnection(conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
return a;
}
}
PS:這裏有一個方法叫做getAllAdm(),還有一個方法叫做getPageAdm()。
前者我是用來獲得總共有多少條管理員信息,後者我是用來獲得分頁信息與分頁數據的,前者本來不需要在數據庫上走那麼多步驟。
因爲ResultSet創建的對象可以使用last()方法跳到最後一條數據,然後再使用getRow()方法獲得總數,這裏建議大家按照這種方法。
⑤Service層:src-->新建package包,命名爲servlet-->新建一個Servlet文件,命名爲LoginServlet-->在URL mappings中改名爲/login-->鍵入代碼,如下
LoginServlet.java文件:
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import dao.AdmDao;
import dao.AdmDaoImpl;
import pojo.Adm;
/**
* Servlet implementation class LoginServlet
WebServlet裏的/login就是剛剛改的URL Mappings的內容
*/
@WebServlet("/login")
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public LoginServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
* void getSession()方法相當於得到一個session對象,而void setAttribute()和String Attribute分別是對屬性賦值和得到屬性值的方法。
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//response.getWriter().append("Served at: ").append(request.getContextPath());
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
String name = request.getParameter("username");
String pwd = request.getParameter("pwd");
AdmDao a = new AdmDaoImpl();
Adm adm = a.getAdm(name , pwd);
System.out.println(a.toString());
if(adm!=null) {
request.getSession().setAttribute("admin",adm);
//重定向到成功頁面
response.sendRedirect("index.jsp");
}else {
//out.println("啊啊啊,我應該轉發到失敗的界面了");
request.setAttribute("errMsg", "賬號或密碼錯誤,請重新輸入信息!");
//轉發到login界面
request.getRequestDispatcher("login.jsp").forward(request, response);
return;
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
⑥WebContent-->新建jsp文件,命名爲login.jsp-->鍵入代碼,如下(使用了bootstrap和layui框架)
login.jsp文件:
<%@ 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">
<link rel="stylesheet" href="./js/bootstrap/css/bootstrap.min.css">
<link rel="stylesheet" href="./css/b_register.css">
<%@include file="base.jsp"%>
<title>登錄</title>
</head>
<body>
<%
String errorMsg = (String) request.getAttribute("errMsg");
if (errorMsg == null) {
errorMsg = "";
}
%>
<div id="box">
<!-- action="${ctx}/login" -->
<form id="myform" method="post" action="${ctx}/login">
<div class="form-group">
<label for="username">用戶名</label> <input type="text"
class="form-control" id="username" name="username"
placeholder="請輸入用戶名:"> <span id="tip"
style="color: red; margin-top: 20px;"><%=errorMsg%></span>
</div>
<div class="form-group">
<label for="pwd">密碼</label> <input type="password"
class="form-control" id="pwd" name="pwd" placeholder="請輸入密碼:">
</div>
<button type="submit" class="btn btn-default btn_" id="btn">確定</button>
<span style="margin-left: 250px;"></span> <a href="register.jsp"><button
type="button" class="btn btn-default btn_">註冊</button></a>
</form>
</div>
<script type="text/javascript">
layui.use([ 'layer' ], function() {
layui.use([ 'form' ], function() {
var form = layui.form;
});
// 點擊提交執行的內容
$('#username').blur(function() {
//或者取長度
if ($("#username").val() == "") {
layer.msg("用戶名不能輸入爲空哦!", {
icon : 2
});
return;
}
});
//點擊提交,表單驗證
$('#btn').click(function() {
if ($("#pwd").val() === "") {
layer.msg("密碼不能輸入爲空哦!", {
icon : 2
});
return;
}
});
});
</script>
</body>
</html>
5.1 這裏CSS目錄如下(CSS並不重要,可以自己調整)
5.2 b_register的css樣式如下
b_register.css文件:
@CHARSET "UTF-8";
*{
margin:0;
padding:0;
}
body{
background:url("./image/19.jpg") no-repeat;
}
#box{
width:520px;
height:400px;
margin:200px auto;
border-radius:20px;
background-color: rgba(0, 0, 0, 0.3);
box-shadow:1px 2px 5px black;
padding: 1px;
position:relative;
background-image: url(./image/18.gif);
opacity: 0.8;
}
#myform{
margin:30px;
}
span{
margin-left:100px;
}
.btn_{
color:tomato;
margin-top:30px;
}
5.3 base的css樣式如下
base.css文件:
@charset "UTF-8";
body {
width: 100%;
height: 100%;
background: url('../css/image/18.gif');
overflow: hidden;
}
#box {
height:550px;
display:flex;
align-items:center;
justify-content:center;
align-content:center;
}
⑤當輸入用戶名或密碼錯誤時,應該有的提示
⑥當輸入密碼正確時,應進入後臺主界面,這裏大家在WebContent裏新建一個jsp文件,取名爲index即可,這裏放一張後臺圖,具體的下篇博文再更
五、註冊模塊
①邏輯分析(以下爲我畫的管理員註冊業務流程圖,註冊成功即自動跳轉登錄頁面)
②Service層:這裏主要就是首先判斷你是否輸入用戶名,用戶名輸入過後判斷是否這個用戶名已經存在(用戶名和id都是唯一的),然後再驗證你兩次密碼是否相同,最後再進入註冊。
所以說前臺可以判斷1是是否輸入2是密碼兩次是否一致;
後臺連接數據庫後應該是進行了兩個操作1是判斷用戶名是否存在2是進行往數據庫裏增加數據
2.1 src-->在servlet包裏-->新建一個Servlet文件,命名爲RegisterServlet-->在URL mappings中改名爲/register-->鍵入代碼,如下
RegisterServlet.java文件:
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import dao.AdmDao;
import dao.AdmDaoImpl;
/**
* Servlet implementation class RegisterServlet
WebServlet裏的/register就是剛剛改的URL Mappings的內容
*/
@WebServlet("/register")
public class RegisterServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public RegisterServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String result = "false";
PrintWriter writer = null;
try {
PrintWriter out = response.getWriter();
//1.接收參數
String username = request.getParameter("username");
String pwd = request.getParameter("pwd");
AdmDao a = new AdmDaoImpl();
boolean flag= a.insertAdm(username,pwd);
if(flag){
result = "true";
}
writer = response.getWriter();
writer.write(result);
}catch(Exception e) {
e.printStackTrace();
}finally {
writer.flush();
writer.close();
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
2.2 src-->在servlet包裏-->新建一個Servlet文件,命名爲QueryAdmIsExist-->在URL mappings中改名爲/isExist-->鍵入代碼,如下
QueryAdmIsExist.java文件:
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import dao.AdmDao;
import dao.AdmDaoImpl;
/**
* Servlet implementation class QueryAdmIsExist
*/
@WebServlet("/isExist")
public class QueryAdmIsExist extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public QueryAdmIsExist() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse resp) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
resp.setCharacterEncoding("utf-8");
resp.setContentType("text/html;charset=utf-8");
//根據姓名查詢用戶是否存在 改的更完善了一點
String result = "false";
PrintWriter writer = null;
try {
String username = request.getParameter("username");
AdmDao a = new AdmDaoImpl();
boolean flag = a.queryIsExist(username);
if(flag==true) {
result = "true";
}
writer = resp.getWriter();
writer.write(result);
} catch (Exception e) {
e.printStackTrace();
}finally {
writer.flush();
writer.close();
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
③在WebContent下-->新建jsp文件,命名爲register.jsp-->鍵入代碼,如下(這裏使用的是ajax,和上面登錄模塊不一樣,注意區別)
register.jsp文件:
<%@ 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">
<link rel="stylesheet" href="./js/bootstrap/css/bootstrap.min.css">
<link rel="stylesheet" href="./css/b_register.css">
<%@include file="base.jsp"%>
<title>註冊</title>
</head>
<body>
<div id="box">
<form id="myform" method="post">
<div class="form-group">
<label for="username">用戶名</label>
<input type="text" class="form-control" id="username" name="username" placeholder="請輸入用戶名:">
<span id="tip" style="color:red;margin-top:20px;"></span>
</div>
<div class="form-group">
<label for="pwd">密碼</label>
<input type="password" class="form-control" id="pwd" name="pwd" placeholder="請輸入密碼:">
</div>
<div class="form-group">
<label for="conFirmPwd">確認密碼</label>
<input type="password" class="form-control" id="conFirmPwd" name="conFirmPwd" placeholder="請再次輸入密碼:">
</div>
<button type="button" class="btn btn-default btn_" id = "btn">提交</button>
<span style="margin-left:250px;"></span>
<a href="login.jsp"><button type="button" class="btn btn-default btn_">返回</button></a>
</form>
</div>
</body>
<script>
layui.use([ 'layer' ], function() {
/* alert(0); */
layui.use([ 'form' ], function() {
var form = layui.form;
});
var isOk = false;
// 點擊提交執行的內容
$('#username').blur(function() {
//或者取長度
if ($("#username").val() == "") {
layer.msg("不能輸入爲空哦!", {
icon : 2
});
return;
}else {
$.post('isExist',
{
username : $('#username').val()
},
function(result) {
//alert(typeof result);
if(result=="true"){
//alert(1);
isOk = false;
//利用jquery對元素設置樣式
$('#username').css("border", "1px solid red");
//html() 設置標籤之間的 內容
$('#tip').html('該用戶已存在');
$('#tip').css("color", "red");
return;
}else{
//alert(2);
isOk = true;
//利用jquery對元素設置樣式
$('#username').css("border", "1px solid gray");
//html() 設置標籤之間的 內容
$('#tip').html('該用戶名可用');
$('#tip').css("color", "green");
}
}, "text");
}
});
//點擊提交,表單驗證
$('#btn').click(function() {
if (!isOk) {
return;
}
if($("#pwd").val() !== $("#conFirmPwd").val()){
layer.msg("兩次密碼輸入不同!",{
icon : 2
});
return;
}
//提交表單
$.post("register",//後臺地址
{
username: $("#username").val(),
pwd:$("#pwd").val(),
},//需要提交到後臺的數據
function(result){
//alert(typeof result);
//alert(result);
if (result) {
//添加成功
layer.msg("註冊成功", {
icon : 1
});
window.location.href = "login.jsp";
}else{
layer.msg("註冊失敗",{
icon : 2
});
// 這裏使用JQuery實現會有問題
document.getElementById("myform").reset();
$('#tip').html("");
}
},
"json");
//清空表單
});
});
</script>
</html>
④註冊時用戶名存在或可用的區別圖片如下