分享第二十四篇励志语句
对自己狠一点，逼自己努力，再过五年你将会感谢今天发狠的自己，恨透今天懒惰自卑的自己，既然认准了一条路，那就坚持走下去，命运不会辜负每一个认真而努力的人。
目录
在MySQL中新建一个servletdatabase数据库，专门用来学习servlet操作数据库
1 案例需求
实现登录功能，登录成功后显示所有管理员信息，登录失败给出“账号或密码错误，无法登录”提示信息
2 创建表admin并添加数据
-
#创建表admin
-
CREATE
TABLE IF
NOT
EXISTS `admin`(
-
`username`
VARCHAR(
20)
PRIMARY KEY,
-
`password`
VARCHAR(
20)
NOT
NULL,
-
`phone`
VARCHAR(
11)
UNIQUE
NOT
NULL,
-
`address`
VARCHAR(
20)
NOT
NULL
-
);
-
-
#向admin表中插入数据
-
INSERT
INTO `admin`(`username`,`password`,`phone`,`address`)
-
VALUES(
'张三',
'123456',
'13112345678',
'安徽合肥蜀山区');
-
-
INSERT
INTO `admin`(`username`,`password`,`phone`,`address`)
-
VALUES(
'李四',
'123456',
'13822334455',
'安徽合肥高新区');
3 创建Web项目
创建Web项目adminProject01，在项目下创建包目录结构如下，并导入相关jar包及配置文件
-
com.cxyzxc.www.dao包：数据访问层接口
-
com.cxyzxc.www.dao.impl包：数据访问层接口实现类
-
com.cxyzxc.www.entity包：实体类
-
com.cxyzxc.www.service包：业务逻辑层接口
-
com.cxyzxc.www.service.impl包：业务逻辑层接口实现类
-
com.cxyzxc.www.servlet包：Servlet类
-
com.cxyzxc.www.utils包：工具类
-
database.properties:数据库连接及连接池配置文件
4 database.properties文件
5 DBUtile类代码
-
package com.cxyzxc.www.utils;
-
-
import java.io.IOException;
-
import java.io.InputStream;
-
import java.util.Properties;
-
import javax.sql.DataSource;
-
import com.alibaba.druid.pool.DruidDataSource;
-
import com.alibaba.druid.pool.DruidDataSourceFactory;
-
-
public
class
DBUtils {
-
-
// 声明一个连接池对象
-
private
static DruidDataSource druidDataSource;
-
-
static {
-
// 实例化配置文件对象
-
Properties
properties
=
new
Properties();
-
-
try {
-
// 加载配置文件内容
-
InputStream
is
= DBUtils.class
-
.getResourceAsStream(
"/database.properties");
-
properties.load(is);
-
// 创建连接池
-
druidDataSource = (DruidDataSource) DruidDataSourceFactory
-
.createDataSource(properties);
-
}
catch (IOException e) {
-
e.printStackTrace();
-
}
catch (Exception e) {
-
e.printStackTrace();
-
}
-
}
-
-
//返回一个数据源
-
public
static DataSource
getDataSource
(){
-
return druidDataSource;
-
}
-
-
}
6 Admin实体类
-
package com.cxyzxc.www.entity;
-
-
public
class
Admin {
-
-
private String username;
-
private String password;
-
private String phone;
-
private String address;
-
-
public
Admin
() {
-
}
-
-
public
Admin
(String username, String password, String phone, String address) {
-
this.username = username;
-
this.password = password;
-
this.phone = phone;
-
this.address = address;
-
}
-
-
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 String
getPhone
() {
-
return phone;
-
}
-
-
public
void
setPhone
(String phone) {
-
this.phone = phone;
-
}
-
-
public String
getAddress
() {
-
return address;
-
}
-
-
public
void
setAddress
(String address) {
-
this.address = address;
-
}
-
-
@Override
-
public String
toString
() {
-
return
"Admin{" +
-
"username='" + username +
'\'' +
-
", password='" + password +
'\'' +
-
", phone='" + phone +
'\'' +
-
", address='" + address +
'\'' +
-
'}';
-
}
-
}
7 AdminDao接口
-
package com.cxyzxc.www.dao;
-
-
import com.cxyzxc.www.entity.Admin;
-
-
import java.util.List;
-
-
public
interface
AdminDao {
-
-
//查询用户（查询单个）
-
Admin
selectOneByUsernameAndPassword
(String username, String password);
-
-
//查询所有用户
-
List<Admin>
selectAll
();
-
}
8 AdminDaoImpl实现类
-
package com.cxyzxc.www.dao.impl;
-
-
import com.cxyzxc.www.dao.AdminDao;
-
import com.cxyzxc.www.entity.Admin;
-
import com.cxyzxc.www.utils.DBUtils;
-
import org.apache.commons.dbutils.QueryRunner;
-
import org.apache.commons.dbutils.handlers.BeanHandler;
-
import org.apache.commons.dbutils.handlers.BeanListHandler;
-
-
import java.sql.SQLException;
-
import java.util.List;
-
-
public
class
AdminDaoImpl
implements
AdminDao {
-
// 创建QueryRunner对象，并传递一个数据源对象
-
private
final
QueryRunner
QUERYRUNNER
=
new
QueryRunner(DBUtils.getDataSource());
-
-
@Override
-
public Admin
selectOneByUsernameAndPassword
(String username, String password) {
-
String
sql
=
"SELECT * FROM `admin` WHERE `username` = ? AND `PASSWORD`=?;";
-
Object[] args = {username, password};
-
try {
-
return QUERYRUNNER.query(sql,
new
BeanHandler<Admin>(Admin.class), args);
-
}
catch (SQLException e) {
-
e.printStackTrace();
-
-
}
-
-
return
null;
-
}
-
-
-
@Override
-
public List<Admin>
selectAll
() {
-
String
sql
=
"SELECT * FROM `admin`;";
-
try {
-
return QUERYRUNNER.query(sql,
new
BeanListHandler<Admin>(Admin.class));
-
}
catch (SQLException e) {
-
e.printStackTrace();
-
}
-
-
return
null;
-
}
-
-
}
9 AdminService接口
-
package com.cxyzxc.www.service;
-
-
import com.cxyzxc.www.entity.Admin;
-
-
import java.util.List;
-
-
public
interface
AdminService {
-
-
Admin
login
(String username, String password);
-
-
List<Admin>
selectAllAdmin
();
-
}
10 AdminServiceImpl实现类
-
package com.cxyzxc.www.service.impl;
-
-
import com.cxyzxc.www.service.AdminService;
-
import com.cxyzxc.www.dao.AdminDao;
-
import com.cxyzxc.www.dao.impl.AdminDaoImpl;
-
import com.cxyzxc.www.entity.Admin;
-
-
import java.util.List;
-
-
public
class
AdminServiceImpl
implements
AdminService {
-
private
final
AdminDao
ADMINDAO
=
new
AdminDaoImpl();
-
-
@Override
-
public Admin
login
(String username, String password) {
-
return ADMINDAO.selectOneByUsernameAndPassword(username, password);
-
}
-
-
@Override
-
public List<Admin>
selectAllAdmin
() {
-
return ADMINDAO.selectAll();
-
}
-
}
11 HTML页面
11.1 login.html页面
-
<!DOCTYPE html>
-
<html lang="en">
-
<head>
-
<meta charset="UTF-8">
-
<title>登录页面
</title>
-
<link type="text/css" rel="stylesheet" href="css/login.css"/>
-
</head>
-
-
<body>
-
<div>
-
<form action="LoginServlet" method="post">
-
<p>
-
账号：
<input type="text" name="username"/>
-
</p>
-
<p>
-
密码：
<input type="password" name="password"/>
-
</p>
-
<p>
-
<input type="submit" value="登录"/>
-
</p>
-
</form>
-
</div>
-
</body>
-
</html>
11.2 login.css
-
* {
-
margin:
0;
-
padding:
0;
-
}
-
-
div {
-
width:
400px;
-
height:
100px;
-
background-color:
#ccc;
-
margin:
30px auto;
-
padding-top:
30px;
-
text-align: center;
-
}
-
-
p {
-
margin-top:
10px;
-
}
-
-
input {
-
outline: none;
-
}
11.3 table.css
-
*{
-
margin:
0;
-
padding:
0;
-
}
-
-
table{
-
margin:
20px auto;
-
width:
500px;
-
height:
100px;
-
text-align: center;
-
}
12 LoginServlet
-
package com.cxyzxc.www.servlet;
-
-
import com.cxyzxc.www.service.AdminService;
-
import com.cxyzxc.www.service.impl.AdminServiceImpl;
-
import com.cxyzxc.www.entity.Admin;
-
-
import javax.servlet.annotation.WebServlet;
-
import javax.servlet.http.HttpServlet;
-
import javax.servlet.http.HttpServletRequest;
-
import javax.servlet.http.HttpServletResponse;
-
import java.io.IOException;
-
import java.io.PrintWriter;
-
-
@WebServlet("/LoginServlet")
-
public
class
LoginServlet
extends
HttpServlet {
-
private
final
AdminService
ADMINSERVICE
=
new
AdminServiceImpl();
-
-
@Override
-
protected
void
doGet
(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
-
req.setCharacterEncoding(
"UTF-8");
-
//获取数据
-
String
username
= req.getParameter(
"username");
-
String
password
= req.getParameter(
"password");
-
-
Admin
admin
= ADMINSERVICE.login(username, password);
-
-
resp.setContentType(
"text/html;charset=UTF-8");
-
PrintWriter
printWriter
= resp.getWriter();
-
-
if (admin !=
null) {
-
printWriter.println(
"<html>");
-
printWriter.println(
"<head>");
-
printWriter.println(
"<title>登录成功</title>");
-
printWriter.println(
"</head>");
-
printWriter.println(
"<body>");
-
printWriter.println(
"<h2>登录成功</h2>");
-
printWriter.println(
"</body>");
-
printWriter.println(
"</html>");
-
}
else {
-
printWriter.println(
"<html>");
-
printWriter.println(
"<head>");
-
printWriter.println(
"<title>登录失败</title>");
-
printWriter.println(
"</head>");
-
printWriter.println(
"<body>");
-
printWriter.println(
"<h2>账号或密码错误，无法登录</h2>");
-
printWriter.println(
"</body>");
-
printWriter.println(
"</html>");
-
-
}
-
-
}
-
-
@Override
-
protected
void
doPost
(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
-
doGet(req, resp);
-
}
-
}
13 ShowAllAdminServlet
-
package com.cxyzxc.www.servlet;
-
-
import com.cxyzxc.www.service.AdminService;
-
import com.cxyzxc.www.service.impl.AdminServiceImpl;
-
import com.cxyzxc.www.entity.Admin;
-
-
import javax.servlet.annotation.WebServlet;
-
import javax.servlet.http.HttpServlet;
-
import javax.servlet.http.HttpServletRequest;
-
import javax.servlet.http.HttpServletResponse;
-
import java.io.IOException;
-
import java.io.PrintWriter;
-
import java.util.List;
-
-
@WebServlet("/ShowAllAdminServlet")
-
public
class
ShowAllAdminServlet
extends
HttpServlet {
-
private
final
AdminService
ADMINSERVICE
=
new
AdminServiceImpl();
-
-
@Override
-
protected
void
doGet
(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
-
req.setCharacterEncoding(
"UTF-8");
-
resp.setContentType(
"text/html;charset=UTF-8");
-
-
PrintWriter
printWriter
= resp.getWriter();
-
List<Admin> adminList = ADMINSERVICE.selectAllAdmin();
-
if (adminList.size() !=
0) {
-
printWriter.println(
"<html>");
-
printWriter.println(
"<head>");
-
printWriter.println(
"<title>所有admin</title>");
-
printWriter.println(
"<link type=\"text/css\" rel=\"stylesheet\" href=\"css/table.css\" />");
-
printWriter.println(
"</head>");
-
printWriter.println(
"<table border='1px' cellspacing='0'>");
-
printWriter.println(
"<tr>");
-
printWriter.println(
"<th>账号</th>");
-
printWriter.println(
"<th>密码</th>");
-
printWriter.println(
"<th>手机号码</th>");
-
printWriter.println(
"<th>住址</th>");
-
printWriter.println(
"<th>操作</th>");
-
printWriter.println(
"</tr>");
-
for (Admin admin : adminList) {
-
printWriter.println(
"<tr>");
-
printWriter.println(
"<td>" + admin.getUsername() +
"</td>");
-
printWriter.println(
"<td>" + admin.getPassword() +
"</td>");
-
printWriter.println(
"<td>" + admin.getPhone() +
"</td>");
-
printWriter.println(
"<td>" + admin.getAddress() +
"</td>");
-
printWriter.println(
"<td><a href=\"#\">修改</a> <a href=\"#\">删除</a></td>");
-
printWriter.println(
"</tr>");
-
}
-
printWriter.println(
"</table>");
-
printWriter.println(
"</html>");
-
}
else {
-
printWriter.println(
"<html>");
-
printWriter.println(
"<head>");
-
printWriter.println(
"<title>所有admin</title>");
-
printWriter.println(
"</head>");
-
printWriter.println(
"<body>");
-
printWriter.println(
"<h2>当前没有用户</h2>");
-
printWriter.println(
"</body>");
-
printWriter.println(
"</html>");
-
}
-
-
}
-
-
@Override
-
protected
void
doPost
(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
-
doGet(req, resp);
-
}
-
}
好了，这些就是单独查和全部查的全部方法，感谢大家支持
今天的分享就到此结束了
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转载：https://blog.csdn.net/swy2560666141/article/details/128465946
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