Servlet 方法介绍
init()：初始化方法- 调用时机：默认情况下，servlet 被第一次访问时，调用
- 可通过
loadOnStartup修改
- 可通过
- 调用次数：1次
- 调用时机：默认情况下，servlet 被第一次访问时，调用
service()：提供服务- 调用时机：每一次Servlet被访问时，调用
- 调用次数：多次
destory()：销毁方法- 调用时机：内存释放或者服务器关闭的时候，Servlet对象会被销毁，调用
- 调用次数：1次
getServletConfig()：获取 ServletConfig 对象getServletInfo()：获取 Servlet 信息（author、version、copyright）
Servlet urlPattern 配置
- 一个 Servlet 可以配置多个 urlPattern
@WebServlet(urlPatterns = {"/demo3", "/demo4"}) - urlPattern 配置规则
- 精确匹配
- 配置路径：
@WebServlet("/demo3") - 访问路径：
localhost:8080/web-demo/demo3
- 配置路径：
- 目录匹配
- 配置路径：
@WebServlet("/user/*") - 访问路径：
localhost:8080/web-demo/user/aaa、localhost:8080/web-demo/user/bbb
- 配置路径：
- 扩展名匹配
- 配置路径：
@WebServlet("*.do") - 访问路径：
localhost:8080/web-demo/aaa.do、localhost:8080/web-demo/bbb.do
- 配置路径：
- 任意匹配
- 配置路径：
@WebServlet("/")、@WebServlet("/*") - 访问路径：
localhost:8080/web-demo/hehe、localhost:8080/web-demo/haha
- 配置路径：
- 精确匹配
/和/*的区别
- 当我们的项目中的Servlet配置了
/，会覆盖掉 tomcat 中的 DefaultServlet，当其他的 url-pattern 都匹配不上时都会走这个Servlet- 当我们的项目中配置了
/*，意味着匹配任意访问路径
优先级：精确路径 > 目录路径 > 扩展名路径 > /* > /
IDEA 模板创建 Servlet
#if (${PACKAGE_NAME} && ${PACKAGE_NAME} != "")package ${PACKAGE_NAME};#end
#parse("File Header.java")
#if ($JAVAEE_TYPE == "jakarta")
import jakarta.servlet.*;
import jakarta.servlet.http.*;
import jakarta.servlet.annotation.*;
#else
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
#end
import java.io.IOException;
@WebServlet("/${Entity_Name}")
public class ${Class_Name} extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}中文乱码问题
POST 乱码
getReader()默认编码是iso-8859-1- 设置字符输入流的编码为
UTF-8：request.setCharacterEncoding("UTF-8");
GET 乱码
URL 编码
- 将字符串按照编码方式转为二进制
- 每个字节转为2个16进制并在前边加上%
URL编解码Demo
package com.ruochen.web;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
public class URLDemo {
public static void main(String[] args) throws UnsupportedEncodingException {
String username = "张三";
// 1. URL 编码
String encode = URLEncoder.encode(username, "utf-8");
System.out.println(encode);
// 2. URL 解码
String decode = URLDecoder.decode(encode, "ISO-8859-1");
System.out.println(decode);
}
}
%E5%BC%A0%E4%B8%89
å¼ ä¸tomcat ISO-8859-1 接码我们无法改变，但是我们可以发现 URL 编码数据和接收打的数据字节是一样的（二进制数据 10101xxxx），这就为我们提供了一种思路：我们可以将乱码的数据转换为字节数据（二进制数据），再将二进制字节数据转换为字符串，demo 如下
package com.ruochen.web;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
public class URLDemo {
public static void main(String[] args) throws UnsupportedEncodingException {
String username = "张三";
// 1. URL 编码
String encode = URLEncoder.encode(username, "utf-8");
System.out.println(encode);
// 2. URL 解码
String decode = URLDecoder.decode(encode, "ISO-8859-1");
System.out.println(decode);
// 3. 转换为字节数据，编码
byte[] bytes = decode.getBytes("ISO-8859-1");
for (byte b : bytes) {
System.out.print(b + " ");
}
System.out.println();
// 4. 将字节数组转换为字符串，解码
String string = new String(bytes, "utf-8");
System.out.println(string);
}
} %E5%BC%A0%E4%B8%89
å¼ ä¸
-27 -68 -96 -28 -72 -119
张三servlet demo
@WebServlet("/req1")
public class RequestDemo1 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 解决post乱码 getReader() 默认编码是 iso-8859-1
request.setCharacterEncoding("UTF-8"); // 设置字符输入流的编码
String username = request.getParameter("username");
System.out.println("解决乱码前：" + username);
// GET 获取参数的方式：getQueryString()
// 乱码原因：tomcat 进行URL解码，默认的字符集ISO-8859-1
// 1. 先对乱码进行编码，转为字节数组
// byte[] bytes = username.getBytes(StandardCharsets.ISO_8859_1);
// 2. 字节数组解码
// username = new String(bytes, StandardCharsets.UTF_8);
username = new String(username.getBytes(StandardCharsets.ISO_8859_1), StandardCharsets.UTF_8);
System.out.println("解决乱码后：" + username);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}Tomcat 8 之后，已将GET请求乱码问题解决，设置默认的解码方式为 UTF-8
路径问题
- 明确路径谁使用？
- 浏览器使用：需要加虚拟目录（项目访问路径）
- 服务端使用：不需要加虚拟目录
- 练习
- <a href = "路径">：加虚拟目录
- <form action="路径">：加虚拟目录
- req.getRequestDispatcher("路径")：不需要加虚拟目录
- resp.sendRedirect("路径")：需要加虚拟目录
Response 响应字符数据
- 使用 Response 对象获取字符输出流：
PrintWriter writer = resp.getWriter(); - 写数据：
write.write("aaa"); - 可通过设置 header 指定类型：
resp.setHeader("content-type", "text/html"); - 流不需要关闭，resp 对象销毁的时候会自动关闭
- 中文乱码，设置流的编码：
resp.setContentType("text/html;charset=utf-8");
Response 响应字节数据
- 通过 Response 对象获取字节输出流：
ServletOutputStream outputStream = resp.getOutputStream(); - 写数据：
outputStream.write(字节数据); - 案例
package com.ruochen.web;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.FileInputStream;
import java.io.IOException;
@WebServlet("/resp1")
public class ResponseDemo1 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 读取文件
FileInputStream fis = new FileInputStream("C:\\Users\\ruochen\\Desktop\\离雨.jpg");
// 2. 获取 response 字节输出流
ServletOutputStream os = response.getOutputStream();
// 3. 完成流的 copy
byte[] buff = new byte[1024];
int len = 0;
while((len = fis.read(buff)) != -1) {
os.write(buff, 0, len);
}
fis.close();
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}- 我们可以使用
commons-io工具类简化上述操作 - 导入坐标：
pom.xml<dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.6</version> </dependency>上述循环遍历代码可简化为如下
IOUtils.copy(fis, os);
用户登录案例
准备工作
login.html放到 webapp 目录下
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>login</title>
<link href="css/login.css" rel="stylesheet">
</head>
<body>
<div id="loginDiv">
<form action="/web-demo/loginServlet" method="post" id="form">
<h1 id="loginMsg">LOGIN IN</h1>
<p>Username:<input id="username" name="username" type="text"></p>
<p>Password:<input id="password" name="password" type="password"></p>
<div id="subDiv">
<input type="submit" class="button" value="login up">
<input type="reset" class="button" value="reset">
<a href="register.html">没有账号？点击注册</a>
</div>
</form>
</div>
</body>
</html>login.css
* {
margin: 0;
padding: 0;
}
html {
height: 100%;
width: 100%;
overflow: hidden;
margin: 0;
padding: 0;
background: url(../imgs/Desert.jpg) no-repeat 0px 0px;
background-repeat: no-repeat;
background-size: 100% 100%;
-moz-background-size: 100% 100%;
}
body {
display: flex;
align-items: center;
justify-content: center;
height: 100%;
}
#loginDiv {
width: 37%;
display: flex;
justify-content: center;
align-items: center;
height: 300px;
background-color: rgba(75, 81, 95, 0.3);
box-shadow: 7px 7px 17px rgba(52, 56, 66, 0.5);
border-radius: 5px;
}
#name_trip {
margin-left: 50px;
color: red;
}
p {
margin-top: 30px;
margin-left: 20px;
color: azure;
}
input {
margin-left: 15px;
border-radius: 5px;
border-style: hidden;
height: 30px;
width: 140px;
background-color: rgba(216, 191, 216, 0.5);
outline: none;
color: #f0edf3;
padding-left: 10px;
}
#username{
width: 200px;
}
#password{
width: 202px;
}
.button {
border-color: cornsilk;
background-color: rgba(100, 149, 237, .7);
color: aliceblue;
border-style: hidden;
border-radius: 5px;
width: 100px;
height: 31px;
font-size: 16px;
}
#subDiv {
text-align: center;
margin-top: 30px;
}
#loginMsg{
text-align: center;color: aliceblue;
} 创建 db1 数据库，创建 tb_user 表，创建 User 实体类
-- 创建数据库
create database db1 character set utf8;
use db1;
-- 创建用户表
CREATE TABLE tb_user(
id int primary key auto_increment,
username varchar(20) unique,
password varchar(32)
);
-- 添加数据
INSERT INTO tb_user(username,password) values('zhangsan','123'),('lisi','234');
SELECT * FROM tb_user;
package com.ruochen.pojo;
public class User {
private Integer id;
private String username;
private String password;
public Integer getId() {
return id;
}
public void setId(Integer 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;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
}导入MyBatis 坐标，MySQL 驱动坐标
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.5</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.34</version>
</dependency> 创建 mybatis-config.xml 核心配置文件，UserMapper.xml 映射文件，UserMapper 接口
mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--起别名-->
<typeAliases>
<package name="com.ruochen.pojo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql:///db1?useSSL=false&useServerPrepStmts=true"/>
<property name="username" value="root"/>
<property name="password" value="ruochen666"/>
</dataSource>
</environment>
</environments>
<mappers>
<!--扫描mapper-->
<package name="com.ruochen.mapper"/>
</mappers>
</configuration>UserMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ruochen.mapper.UserMapper">
</mapper>UserMapper.java
package com.ruochen.mapper;
public interface UserMapper {
}目录树如下
流程
UserMapper.java
package com.ruochen.mapper;
import com.ruochen.pojo.User;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
public interface UserMapper {
/**
* 根据用户名和密码查询用户对象
* @param username
* @param password
* @return
*/
@Select("select * from tb_user where username= #{username} and password = #{password}")
User select(@Param("username") String username, @Param("password") String password);
}UserServlet.java
package com.ruochen.web;
import com.ruochen.mapper.UserMapper;
import com.ruochen.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 接收用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
// 2. 调用 MyBatis 完成查询
// 2.1 获取 SqlSessionFactory 对象
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
// 2.2 获取 SqlSession 对象
SqlSession sqlSession = sqlSessionFactory.openSession();
// 2.3 获取 Mapper
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
// 2.4 调用方法
User user = userMapper.select(username, password);
// 2.5 释放资源
sqlSession.close();
// 获取字符输出流，并设置 content-type
response.setContentType("text/html;charset=utf-8");
PrintWriter writer = response.getWriter();
// 3. 判断 User 是否为 null
if (user != null) {
// 登录成功
writer.write("登录成功");
} else {
// 登录失败
writer.write("登录失败");
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}用户注册案例
register.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>欢迎注册</title>
<link href="css/register.css" rel="stylesheet">
</head>
<body>
<div class="form-div">
<div class="reg-content">
<h1>欢迎注册</h1>
<span>已有帐号？</span> <a href="login.html">登录</a>
</div>
<form id="reg-form" action="#" method="get">
<table>
<tr>
<td>用户名</td>
<td class="inputs">
<input name="username" type="text" id="username">
<br>
<span id="username_err" class="err_msg" style="display: none">用户名不太受欢迎</span>
</td>
</tr>
<tr>
<td>密码</td>
<td class="inputs">
<input name="password" type="password" id="password">
<br>
<span id="password_err" class="err_msg" style="display: none">密码格式有误</span>
</td>
</tr>
</table>
<div class="buttons">
<input value="注 册" type="submit" id="reg_btn">
</div>
<br class="clear">
</form>
</div>
</body>
</html>UserMapper.java
/**
* 根据用户名查询用户对象
* @param username
* @return
*/
@Select("select * from tb_user where username = #{username}")
User selectByUserName(String username);
/**
* 添加用户
* @param user
*/
@Insert("insert into tb_user values (null, #{username}, #{password});")
void add(User user);RegisterServlet
package com.ruochen.web;
import com.ruochen.mapper.UserMapper;
import com.ruochen.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.io.InputStream;
@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 接收用户数据
String username = request.getParameter("username");
String password = request.getParameter("password");
// 封装用户对象
User user = new User();
user.setUsername(username);
user.setPassword(password);
// 2. 调用 Mapper 根据用户名查询用户对象
// 2.1 获取 SqlSessionFactory 对象
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
// 2.2 获取 SqlSession 对象
SqlSession sqlSession = sqlSessionFactory.openSession();
// 2.3 获取 Mapper
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
// 2.4 调用方法
User u = userMapper.selectByUserName(username);
// 3. 判断用户对象是否为 null
if (u == null) {
// 用户名不存在，添加用户
userMapper.add(user);
// 提交事务
sqlSession.commit();
} else {
// 用户名存在，给出提示信息
response.setContentType("text/html;charset=utf-8");
response.getWriter().write("用户名已存在");
}
// 释放资源
sqlSession.close();
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}代码优化
- 创建 SqlSessionFactory 代码优化
- 代码重复：工具类
- SqlSessionFacroty 工厂只创建一次，不要重复创建：静态代码块
package com.ruochen.util;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.IOException;
import java.io.InputStream;
public class SqlSessionFactoryUtils {
private static SqlSessionFactory sqlSessionFactory;
static {
// 静态代码块会随着类的加载自动执行，且只执行一次
try {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
}
public static SqlSessionFactory getSqlSessionFactory() {
return sqlSessionFactory;
}
}案例
准备工作
- 创建新的模块
brand_demo，引入坐标
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.ruochen</groupId>
<artifactId>brand-demo</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
</properties>
<dependencies>
<!--mybatis-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.5</version>
</dependency>
<!--mysql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.34</version>
</dependency>
<!--servlet-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<!--jsp-->
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.2</version>
<scope>provided</scope>
</dependency>
<!--jstl-->
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!--standard-->
<!--jstl 1.2 版本不需要此依赖-->
<!--
<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>
-->
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.1</version>
</plugin>
</plugins>
</build>
</project>创建三层架构的包结构
数据库表 tb_brand
-- 创建数据库
create database db1 character set utf8;
use db1;
-- 删除tb_brand表
drop table if exists tb_brand;
-- 创建tb_brand表
create table tb_brand
(
-- id 主键
id int primary key auto_increment,
-- 品牌名称
brand_name varchar(20),
-- 企业名称
company_name varchar(20),
-- 排序字段
ordered int,
-- 描述信息
description varchar(100),
-- 状态：0：禁用 1：启用
status int
);
-- 添加数据
insert into tb_brand (brand_name, company_name, ordered, description, status)
values ('三只松鼠', '三只松鼠股份有限公司', 5, '好吃不上火', 0),
('华为', '华为技术有限公司', 100, '华为致力于把数字世界带入每个人、每个家庭、每个组织，构建万物互联的智能世界', 1),
('小米', '小米科技有限公司', 50, 'are you ok', 1);
SELECT * FROM tb_brand; 实体类 Brand
package com.ruochen.pojo;
/**
* 品牌实体类
*/
public class Brand {
// id 主键
private Integer id;
// 品牌名称
private String brandName;
// 企业名称
private String companyName;
// 排序字段
private Integer ordered;
// 描述信息
private String description;
// 状态：0：禁用 1：启用
private Integer status;
public Brand() {
}
public Brand(Integer id, String brandName, String companyName, String description) {
this.id = id;
this.brandName = brandName;
this.companyName = companyName;
this.description = description;
}
public Brand(Integer id, String brandName, String companyName, Integer ordered, String description, Integer status) {
this.id = id;
this.brandName = brandName;
this.companyName = companyName;
this.ordered = ordered;
this.description = description;
this.status = status;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getBrandName() {
return brandName;
}
public void setBrandName(String brandName) {
this.brandName = brandName;
}
public String getCompanyName() {
return companyName;
}
public void setCompanyName(String companyName) {
this.companyName = companyName;
}
public Integer getOrdered() {
return ordered;
}
public void setOrdered(Integer ordered) {
this.ordered = ordered;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Integer getStatus() {
return status;
}
public void setStatus(Integer status) {
this.status = status;
}
@Override
public String toString() {
return "Brand{" +
"id=" + id +
", brandName='" + brandName + '\'' +
", companyName='" + companyName + '\'' +
", ordered=" + ordered +
", description='" + description + '\'' +
", status=" + status +
'}';
}
}MyBatis 基础环境
MyBatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--起别名-->
<typeAliases>
<package name="com.ruochen.pojo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url"
value="jdbc:mysql:///db1?useSSL=false&useServerPrepStmts=true&useUnicode=true&characterEncoding=UTF-8"/>
<property name="username" value="root"/>
<property name="password" value="ruochen666"/>
</dataSource>
</environment>
</environments>
<mappers>
<!--扫描mapper-->
<package name="com.ruochen.mapper"/>
</mappers>
</configuration>BrandMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ruochen.mapper.BrandMapper">
</mapper> BrandMapper 接口
package com.ruochen.mapper;
public interface BrandMapper {
}目录树如下
业务 - 查询所有
Dao 层：BrandMapper
/**
* 查询所有
* @return
*/
@Select("select * from tb_brand")
@ResultMap("brandResultMap")
List<Brand> selectAll();BrandMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ruochen.mapper.BrandMapper">
<resultMap id="brandResultMap" type="brand">
<result column="brand_name" property="brandName"></result>
<result column="company_name" property="companyName"></result>
</resultMap>
</mapper> 工具类：SqlSessionFactoryUtils
package com.ruochen.utils;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.IOException;
import java.io.InputStream;
public class SqlSessionFactoryUtils {
private static SqlSessionFactory sqlSessionFactory;
static {
//静态代码块会随着类的加载而自动执行，且只执行一次
try {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
}
public static SqlSessionFactory getSqlSessionFactory(){
return sqlSessionFactory;
}
} Service 层：BrandService
package com.ruochen.service;
import com.ruochen.mapper.BrandMapper;
import com.ruochen.pojo.Brand;
import com.ruochen.utils.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import java.util.List;
public class BrandService {
// 1. 获取 sqlSessionFactory
SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
/**
* 查询所有功能
* @return
*/
public List<Brand> selectAll() {
// 调用BrandMapper.selectAll()
// 2. 获取 SqlSession
SqlSession sqlSession = factory.openSession();
// 3. 获取 BrandMapper
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
// 4. 调用方法
List<Brand> brands = mapper.selectAll();
// 5. 释放资源
sqlSession.close();
return brands;
}
}Web 层
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<a href="/brand-demo/selectAllServlet">查询所有</a>
</body>
</html>SelectAllServlet
package com.ruochen.web;
import com.ruochen.pojo.Brand;
import com.ruochen.service.BrandService;
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 java.io.IOException;
import java.util.List;
@WebServlet("/selectAllServlet")
public class SelectAllServlet extends HttpServlet {
private BrandService brandService = new BrandService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 调用 BrandService 完成查询
List<Brand> brands = brandService.selectAll();
// 2. 存入request域中
request.setAttribute("brand", brands);
// 3. 转发到 brand.jsp
request.getRequestDispatcher("/brand.jsp").forward(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}brand.jsp
<%--
Created by IntelliJ IDEA.
User: ruochen
Date: 2022/2/27
Time: 12:33
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<input type="button" value="新增"><br>
<hr>
<table border="1" cellspacing="0" width="80%">
<tr>
<th>序号</th>
<th>品牌名称</th>
<th>企业名称</th>
<th>排序</th>
<th>品牌介绍</th>
<th>状态</th>
<th>操作</th>
</tr>
<c:forEach items="${brands}" var="brand" varStatus="status">
<tr align="center">
<td>${status.count}</td>
<td>${brand.brandName}</td>
<td>${brand.companyName}</td>
<td>${brand.ordered}</td>
<td>${brand.description}</td>
<c:if test="${brand.status == 1}">
<td>启用</td>
</c:if>
<c:if test="${brand.status != 1}">
<td>禁用</td>
</c:if>
<td><a href="#">修改</a> <a href="#">删除</a></td>
</tr>
</c:forEach>
</table>
</body>
</html>测试
注意点：resultMap 的使用：属性名称和数据库字段名称不一致
业务 - 添加
Dao 层：BrandMapper
@Insert("insert into tb_brand values (null, #{brandName}, #{companyName}, #{ordered}, #{description}, #{status});")
void add(Brand brand);Service 层：BrandService
/**
* 添加
* @param brand
*/
public void add(Brand brand) {
// 2. 获取 SqlSession
SqlSession sqlSession = factory.openSession();
// 3. 获取 BrandMapper
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
// 4. 调用方法
mapper.add(brand);
// 提交事务
sqlSession.commit();
// 释放资源
sqlSession.close();
} Web 层：brand.jsp
<%--
Created by IntelliJ IDEA.
User: ruochen
Date: 2022/2/27
Time: 12:33
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<input type="button" value="新增" id="add"><br>
<hr>
<table border="1" cellspacing="0" width="80%">
<tr>
<th>序号</th>
<th>品牌名称</th>
<th>企业名称</th>
<th>排序</th>
<th>品牌介绍</th>
<th>状态</th>
<th>操作</th>
</tr>
<c:forEach items="${brands}" var="brand" varStatus="status">
<tr align="center">
<td>${status.count}</td>
<td>${brand.brandName}</td>
<td>${brand.companyName}</td>
<td>${brand.ordered}</td>
<td>${brand.description}</td>
<c:if test="${brand.status == 1}">
<td>启用</td>
</c:if>
<c:if test="${brand.status != 1}">
<td>禁用</td>
</c:if>
<td><a href="#">修改</a> <a href="#">删除</a></td>
</tr>
</c:forEach>
</table>
</body>
<script>
document.getElementById("add").onclick = function () {
location.href = "/brand-demo/addBrand.jsp";
}
</script>
</html>addBrand.jsp
<%--
Created by IntelliJ IDEA.
User: ruochen
Date: 2022/2/27
Time: 13:32
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<meta charset="UTF-8">
<title>添加品牌</title>
</head>
<body>
<h3>添加品牌</h3>
<form action="/brand-demo/AddServlet" method="post">
品牌名称：<input name="brandName"><br>
企业名称：<input name="companyName"><br>
排序：<input name="ordered"><br>
描述信息：<textarea rows="5" cols="20" name="description"></textarea><br>
状态：
<input type="radio" name="status" value="0">禁用
<input type="radio" name="status" value="1">启用<br>
<input type="submit" value="提交">
</form>
</body>
</html>AddBrandServlet
package com.ruochen.web;
import com.ruochen.pojo.Brand;
import com.ruochen.service.BrandService;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebServlet("/addServlet")
public class AddServlet extends HttpServlet {
private BrandService service = new BrandService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 接收表单提交的数据，封装为一个 Brand 对象
String brandName = request.getParameter("brandName");
String companyName = request.getParameter("companyName");
String ordered = request.getParameter("ordered");
String description = request.getParameter("description");
String status = request.getParameter("status");
Brand brand = new Brand();
brand.setBrandName(brandName);
brand.setCompanyName(companyName);
brand.setOrdered(Integer.parseInt(ordered));
brand.setDescription(description);
brand.setStatus(Integer.parseInt(status));
// 2. 调用 service 完成添加
service.add(brand);
// 3. 转发到查询所有 Servlet
request.getRequestDispatcher("/selectAllServlet").forward(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}测试
业务 - 修改（数据回显）
Dao 层：BrandMapper
/**
* 根据 id 查询
* @param id
* @return
*/
@Select("select * from tb_brand where id = #{id}")
@ResultMap("brandResultMap")
Brand selectById(int id); Service 层：BrandService
/**
* 根据 id 查询
* @param id
* @return
*/
public Brand selectById(int id) {
// 调用BrandMapper.selectAll()
// 2. 获取 SqlSession
SqlSession sqlSession = factory.openSession();
// 3. 获取 BrandMapper
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
// 4. 调用方法
Brand brand = mapper.selectById(id);
// 5. 释放资源
sqlSession.close();
return brand;
}Web 层：brand.jsp
<td><a href="/brand-demo/selectByIdServlet?id=${brand.id}">修改</a> <a href="#">删除</a></td>SelectByIdServlet
package com.ruochen.web;
import com.ruochen.pojo.Brand;
import com.ruochen.service.BrandService;
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 java.io.IOException;
@WebServlet("/selectByIdServlet")
public class SelectByIdServlet extends HttpServlet {
private BrandService brandService = new BrandService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 接收id
String id = request.getParameter("id");
// 2. 调用 service
Brand brand = brandService.selectById(Integer.parseInt(id));
// 3. 存储到 request 中
request.setAttribute("brand", brand);
// 4. 转发到 update.jsp
request.getRequestDispatcher("/update.jsp").forward(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}update.jsp
<%--
Created by IntelliJ IDEA.
User: ruochen
Date: 2022/2/27
Time: 13:32
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<meta charset="UTF-8">
<title>修改品牌</title>
</head>
<body>
<h3>修改品牌</h3>
<form action="#" method="post">
品牌名称：<input name="brandName" value="${brand.brandName}"><br>
企业名称：<input name="companyName" value="${brand.companyName}"><br>
排序：<input name="ordered" value="${brand.ordered}"><br>
描述信息：<textarea rows="5" cols="20" name="description">${brand.description}</textarea><br>
状态：
<c:if test="${brand.status == 0}">
<input type="radio" name="status" value="0" checked>禁用
<input type="radio" name="status" value="1">启用<br>
</c:if>
<c:if test="${brand.status == 1}">
<input type="radio" name="status" value="0">禁用
<input type="radio" name="status" value="1" checked>启用<br>
</c:if>
<input type="submit" value="提交">
</form>
</body>
</html>测试
业务 - 修改（修改数据）
Dao 层：BrandMapper
/**
* 修改
* @param brand
*/
@Update("update tb_brand set brand_name = #{brandName}, company_name = #{companyName}, ordered = #{ordered}, " +
"description = #{description}, status = #{status} where id = #{id}")
void update(Brand brand);Service 层：BrandService
/**
* 修改
* @param brand
*/
public void update(Brand brand) {
// 2. 获取 SqlSession
SqlSession sqlSession = factory.openSession();
// 3. 获取 BrandMapper
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
// 4. 调用方法
mapper.update(brand);
// 提交事务
sqlSession.commit();
// 释放资源
sqlSession.close();
}Web 层：update.jsp
<%--
Created by IntelliJ IDEA.
User: ruochen
Date: 2022/2/27
Time: 13:32
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<meta charset="UTF-8">
<title>修改品牌</title>
</head>
<body>
<h3>修改品牌</h3>
<form action="/brand-demo/updateServlet" method="post">
<%-- 隐藏域，提交 id --%>
<input type="hidden" name="id" value="${brand.id}">
品牌名称：<input name="brandName" value="${brand.brandName}"><br>
企业名称：<input name="companyName" value="${brand.companyName}"><br>
排序：<input name="ordered" value="${brand.ordered}"><br>
描述信息：<textarea rows="5" cols="20" name="description">${brand.description}</textarea><br>
状态：
<c:if test="${brand.status == 0}">
<input type="radio" name="status" value="0" checked>禁用
<input type="radio" name="status" value="1">启用<br>
</c:if>
<c:if test="${brand.status == 1}">
<input type="radio" name="status" value="0">禁用
<input type="radio" name="status" value="1" checked>启用<br>
</c:if>
<input type="submit" value="提交">
</form>
</body>
</html>updateServlet
package com.ruochen.web;
import com.ruochen.pojo.Brand;
import com.ruochen.service.BrandService;
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 java.io.IOException;
@WebServlet("/updateServlet")
public class UpdateServlet extends HttpServlet {
private BrandService service = new BrandService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 处理 post 请求的乱码问题
request.setCharacterEncoding("utf-8");
// 1. 接收表单提交的数据，封装为一个 Brand 对象
String id = request.getParameter("id");
String brandName = request.getParameter("brandName");
String companyName = request.getParameter("companyName");
String ordered = request.getParameter("ordered");
String description = request.getParameter("description");
String status = request.getParameter("status");
Brand brand = new Brand();
brand.setId(Integer.parseInt(id));
brand.setBrandName(brandName);
brand.setCompanyName(companyName);
brand.setOrdered(Integer.parseInt(ordered));
brand.setDescription(description);
brand.setStatus(Integer.parseInt(status));
// 2. 调用 service 完成修改
service.update(brand);
// 3. 转发到查询所有 Servlet
request.getRequestDispatcher("/selectAllServlet").forward(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}测试
业务 - 删除
Dao 层：BrandMapper
/**
* 删除
* @param id
*/
@Delete("delete from tb_brand where id = #{id}")
void delete(int id);Service 层：BrandService
/**
* 删除
* @param id
*/
public void delete(int id) {
// 2. 获取 SqlSession
SqlSession sqlSession = factory.openSession();
// 3. 获取 BrandMapper
BrandMapper mapper = sqlSession.getMapper(BrandMapper.class);
// 4. 调用方法
mapper.delete(id);
// 提交事务
sqlSession.commit();
// 释放资源
sqlSession.close();
}
Web 层：brand.jsp
<td><a href="/brand-demo/selectByIdServlet?id=${brand.id}">修改</a> <a
href="/brand-demo/deleteServlet?id=${brand.id}">删除</a></td>DeleteServlet
package com.ruochen.web;
import com.ruochen.pojo.Brand;
import com.ruochen.service.BrandService;
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 java.io.IOException;
@WebServlet("/deleteServlet")
public class DeleteServlet extends HttpServlet {
private BrandService service = new BrandService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 接收 id
String id = request.getParameter("id");
// 2. 调用 service
service.delete(Integer.parseInt(id));
// 3. 转发到查询所有 Servlet
request.getRequestDispatcher("/selectAllServlet").forward(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}测试
业务 - 用户登录
Dao 层：UserMapper.java
package com.ruochen.mapper;
import com.ruochen.pojo.User;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
public interface UserMapper {
/**
* 根据用户名和密码查询用户对象
* @param username
* @param password
* @return
*/
@Select("select * from tb_user where username = #{username} and password = #{password}")
User select(@Param("username") String username,@Param("password") String password);
/**
* 根据用户名查询用户对象
* @param username
* @return
*/
@Select("select * from tb_user where username = #{username}")
User selectByUsername(String username);
/**
* 添加用户
* @param user
*/
@Insert("insert into tb_user values(null,#{username},#{password})")
void add(User user);
}User.java
package com.ruochen.pojo;
public class User {
private Integer id;
private String username;
private String password;
public Integer getId() {
return id;
}
public void setId(Integer 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;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
}UserMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ruochen.mapper.UserMapper">
</mapper> Service 层：UserService.java
package com.ruochen.service;
import com.ruochen.mapper.UserMapper;
import com.ruochen.pojo.User;
import com.ruochen.utils.SqlSessionFactoryUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
public class UserService {
SqlSessionFactory factory = SqlSessionFactoryUtils.getSqlSessionFactory();
/**
* 登录方法
* @param username
* @param password
* @return
*/
public User login(String username, String password) {
// 2. 获取 SqlSession
SqlSession sqlSession = factory.openSession();
// 3. 获取 UserMapper
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
// 4. 调用方法
User user = mapper.select(username, password);
// 5. 释放资源
sqlSession.close();
return user;
}
} Web 层：login.jsp
<%--
Created by IntelliJ IDEA.
User: ruochen
Date: 2022/2/27
Time: 15:45
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<meta charset="UTF-8">
<title>login</title>
<link href="css/login.css" rel="stylesheet">
</head>
<body>
<div id="loginDiv" style="height: 350px">
<form action="/brand-demo/loginServlet" id="form">
<h1 id="loginMsg">LOGIN IN</h1>
<div id="errorMsg">${login_msg}</div>
<p>Username:<input id="username" name="username" type="text"></p>
<p>Password:<input id="password" name="password" type="password"></p>
<p>Remember:<input id="remember" name="remember" type="checkbox"></p>
<div id="subDiv">
<input type="submit" class="button" value="login up">
<input type="reset" class="button" value="reset">
<a href="register.html">没有账号？</a>
</div>
</form>
</div>
</body>
</html>brand.jsp 添加
<h1>${user.username}，欢迎您</h1>LoginServlet
package com.ruochen.web;
import com.ruochen.pojo.User;
import com.ruochen.service.UserService;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
private UserService service = new UserService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 获取用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
// 2. 调用 service 查询
User user = service.login(username, password);
// 3. 判断
if (user != null) {
// 登录成功,，跳转到查询所有的 BrandServlet
// 将登录成功的user对象存储到 session
HttpSession session = request.getSession();
session.setAttribute("user", user);
String contextPath = request.getContextPath();
response.sendRedirect(contextPath + "/selectAllServlet");
} else {
// 登录失败
// 存储错误信息到 request
request.setAttribute("login_msg", "用户名或密码错误");
// 跳转到 login.jsp
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
测试
业务 - 记住用户
- 如何自动填充用户名和密码？
- 将用户名和密码写入Cookie中，并且持久化存储 Cookie，下次访问浏览器会自动携带 Cookie
- 在页面获取 Cookie 数据后，设置到用户名和密码框中
- 何时写 Cookie？
- 登录成功
- 用户勾选记住用户复选框
LoginServlet
package com.ruochen.web;
import com.ruochen.pojo.User;
import com.ruochen.service.UserService;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
private UserService service = new UserService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 获取用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
// 获取复选框数据
String remember = request.getParameter("remember");
// 2. 调用 service 查询
User user = service.login(username, password);
// 3. 判断
if (user != null) {
// 登录成功,，跳转到查询所有的 BrandServlet
// 判断用户是否勾选记住我
if ("1".equals(remember)) {
// 勾选了，发送 Cookie
// 1. 创建 Cookie 对象
Cookie c_username = new Cookie("username", username);
Cookie c_password = new Cookie("password", password);
// 设置 Cookie 存活时间
c_username.setMaxAge(60 * 60 * 24 * 7);
c_password.setMaxAge(60 * 60 * 24 * 7);
// 2. 发送 Cookie
response.addCookie(c_username);
response.addCookie(c_password);
}
// 将登录成功的user对象存储到 session
HttpSession session = request.getSession();
session.setAttribute("user", user);
String contextPath = request.getContextPath();
response.sendRedirect(contextPath + "/selectAllServlet");
} else {
// 登录失败
// 存储错误信息到 request
request.setAttribute("login_msg", "用户名或密码错误");
// 跳转到 login.jsp
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}login.jsp
<%--
Created by IntelliJ IDEA.
User: ruochen
Date: 2022/2/27
Time: 15:45
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<meta charset="UTF-8">
<title>login</title>
<link href="css/login.css" rel="stylesheet">
</head>
<body>
<div id="loginDiv" style="height: 350px">
<form action="/brand-demo/loginServlet" method="post" id="form">
<h1 id="loginMsg">LOGIN IN</h1>
<div id="errorMsg">${login_msg}</div>
<p>Username:<input id="username" name="username" value="${cookie.username.value}" type="text"></p>
<p>Password:<input id="password" name="password" value="${cookie.password.value}" type="password"></p>
<p>Remember:<input id="remember" name="remember" value="1" type="checkbox"></p>
<div id="subDiv">
<input type="submit" class="button" value="login up">
<input type="reset" class="button" value="reset">
<a href="register.html">没有账号？</a>
</div>
</form>
</div>
</body>
</html>测试
业务 - 注册
UserService.java
/**
* 注册方法
*
* @param user
* @return
*/
public boolean register(User user) {
// 2. 获取 SqlSession
SqlSession sqlSession = factory.openSession();
// 3. 获取 UserMapper
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
// 4. 判断用户名是否存在
User u = mapper.selectByUsername(user.getUsername());
if (u == null) {
// 用户名不存在，注册
mapper.add(user);
sqlSession.commit();
}
sqlSession.close();
return u == null;
}register.jsp
<%--
Created by IntelliJ IDEA.
User: ruochen
Date: 2022/2/27
Time: 16:24
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<meta charset="UTF-8">
<title>欢迎注册</title>
<link href="css/register.css" rel="stylesheet">
</head>
<body>
<div class="form-div">
<div class="reg-content">
<h1>欢迎注册</h1>
<span>已有帐号？</span> <a href="login.html">登录</a>
</div>
<form id="reg-form" action="/brand-demo/registerServlet" method="post">
<table>
<tr>
<td>用户名</td>
<td class="inputs">
<input name="username" type="text" id="username">
<br>
<span id="username_err" class="err_msg">${register_msg}</span>
</td>
</tr>
<tr>
<td>密码</td>
<td class="inputs">
<input name="password" type="password" id="password">
<br>
<span id="password_err" class="err_msg" style="display: none">密码格式有误</span>
</td>
</tr>
<tr>
<td>验证码</td>
<td class="inputs">
<input name="checkCode" type="text" id="checkCode">
<img src="imgs/a.jpg">
<a href="#" id="changeImg">看不清？</a>
</td>
</tr>
</table>
<div class="buttons">
<input value="注 册" type="submit" id="reg_btn">
</div>
<br class="clear">
</form>
</div>
</body>
</html> login.jsp 添加
<div id="errorMsg">${login_msg} ${register_msg}</div>
<a href="register.jsp">没有账号？</a>RegisterServlet
package com.ruochen.web;
import com.ruochen.pojo.User;
import com.ruochen.service.UserService;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {
private UserService service = new UserService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 获取用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
User user = new User();
user.setUsername(username);
user.setPassword(password);
// 2. 调用 service 注册
boolean flag = service.register(user);
// 3. 判断注册成功与否
if (flag) {
// 注册成功，跳转登录页面
request.setAttribute("register_msg", "注册成功，请登录");
request.getRequestDispatcher("/login.jsp").forward(request, response);
} else {
// 注册失败，跳转到注册页面
request.setAttribute("register_msg", "用户名已存在");
request.getRequestDispatcher("/register.jsp").forward(request, response);
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}测试
业务 - 注册验证码
验证码工具类：checkCodeUtil.java
package com.ruochen.utils;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Arrays;
import java.util.Random;
/**
* 生成验证码工具类
*/
public class CheckCodeUtil {
public static final String VERIFY_CODES = "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
private static Random random = new Random();
/**
* 输出随机验证码图片流,并返回验证码值（一般传入输出流，响应response页面端，Web项目用的较多）
*
* @param w 图片宽度
* @param h 图片高度
* @param os 输出流
* @param verifySize 数据长度
* @return 验证码数据
* @throws IOException
*/
public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException {
String verifyCode = generateVerifyCode(verifySize);
outputImage(w, h, os, verifyCode);
return verifyCode;
}
/**
* 使用系统默认字符源生成验证码
*
* @param verifySize 验证码长度
* @return
*/
public static String generateVerifyCode(int verifySize) {
return generateVerifyCode(verifySize, VERIFY_CODES);
}
/**
* 使用指定源生成验证码
*
* @param verifySize 验证码长度
* @param sources 验证码字符源
* @return
*/
public static String generateVerifyCode(int verifySize, String sources) {
// 未设定展示源的字码，赋默认值大写字母+数字
if (sources == null || sources.length() == 0) {
sources = VERIFY_CODES;
}
int codesLen = sources.length();
Random rand = new Random(System.currentTimeMillis());
StringBuilder verifyCode = new StringBuilder(verifySize);
for (int i = 0; i < verifySize; i++) {
verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));
}
return verifyCode.toString();
}
/**
* 生成随机验证码文件,并返回验证码值 (生成图片形式，用的较少)
*
* @param w
* @param h
* @param outputFile
* @param verifySize
* @return
* @throws IOException
*/
public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException {
String verifyCode = generateVerifyCode(verifySize);
outputImage(w, h, outputFile, verifyCode);
return verifyCode;
}
/**
* 生成指定验证码图像文件
*
* @param w
* @param h
* @param outputFile
* @param code
* @throws IOException
*/
public static void outputImage(int w, int h, File outputFile, String code) throws IOException {
if (outputFile == null) {
return;
}
File dir = outputFile.getParentFile();
//文件不存在
if (!dir.exists()) {
//创建
dir.mkdirs();
}
try {
outputFile.createNewFile();
FileOutputStream fos = new FileOutputStream(outputFile);
outputImage(w, h, fos, code);
fos.close();
} catch (IOException e) {
throw e;
}
}
/**
* 输出指定验证码图片流
*
* @param w
* @param h
* @param os
* @param code
* @throws IOException
*/
public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {
int verifySize = code.length();
BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Random rand = new Random();
Graphics2D g2 = image.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// 创建颜色集合，使用java.awt包下的类
Color[] colors = new Color[5];
Color[] colorSpaces = new Color[]{Color.WHITE, Color.CYAN,
Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
Color.PINK, Color.YELLOW};
float[] fractions = new float[colors.length];
for (int i = 0; i < colors.length; i++) {
colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
fractions[i] = rand.nextFloat();
}
Arrays.sort(fractions);
// 设置边框色
g2.setColor(Color.GRAY);
g2.fillRect(0, 0, w, h);
Color c = getRandColor(200, 250);
// 设置背景色
g2.setColor(c);
g2.fillRect(0, 2, w, h - 4);
// 绘制干扰线
Random random = new Random();
// 设置线条的颜色
g2.setColor(getRandColor(160, 200));
for (int i = 0; i < 20; i++) {
int x = random.nextInt(w - 1);
int y = random.nextInt(h - 1);
int xl = random.nextInt(6) + 1;
int yl = random.nextInt(12) + 1;
g2.drawLine(x, y, x + xl + 40, y + yl + 20);
}
// 添加噪点
// 噪声率
float yawpRate = 0.05f;
int area = (int) (yawpRate * w * h);
for (int i = 0; i < area; i++) {
int x = random.nextInt(w);
int y = random.nextInt(h);
// 获取随机颜色
int rgb = getRandomIntColor();
image.setRGB(x, y, rgb);
}
// 添加图片扭曲
shear(g2, w, h, c);
g2.setColor(getRandColor(100, 160));
int fontSize = h - 4;
Font font = new Font("Algerian", Font.ITALIC, fontSize);
g2.setFont(font);
char[] chars = code.toCharArray();
for (int i = 0; i < verifySize; i++) {
AffineTransform affine = new AffineTransform();
affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize / 2, h / 2);
g2.setTransform(affine);
g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);
}
g2.dispose();
ImageIO.write(image, "jpg", os);
}
/**
* 随机颜色
*
* @param fc
* @param bc
* @return
*/
private static Color getRandColor(int fc, int bc) {
if (fc > 255) {
fc = 255;
}
if (bc > 255) {
bc = 255;
}
int r = fc + random.nextInt(bc - fc);
int g = fc + random.nextInt(bc - fc);
int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}
private static int getRandomIntColor() {
int[] rgb = getRandomRgb();
int color = 0;
for (int c : rgb) {
color = color << 8;
color = color | c;
}
return color;
}
private static int[] getRandomRgb() {
int[] rgb = new int[3];
for (int i = 0; i < 3; i++) {
rgb[i] = random.nextInt(255);
}
return rgb;
}
private static void shear(Graphics g, int w1, int h1, Color color) {
shearX(g, w1, h1, color);
shearY(g, w1, h1, color);
}
private static void shearX(Graphics g, int w1, int h1, Color color) {
int period = random.nextInt(2);
boolean borderGap = true;
int frames = 1;
int phase = random.nextInt(2);
for (int i = 0; i < h1; i++) {
double d = (double) (period >> 1)
* Math.sin((double) i / (double) period
+ (6.2831853071795862D * (double) phase)
/ (double) frames);
g.copyArea(0, i, w1, 1, (int) d, 0);
if (borderGap) {
g.setColor(color);
g.drawLine((int) d, i, 0, i);
g.drawLine((int) d + w1, i, w1, i);
}
}
}
private static void shearY(Graphics g, int w1, int h1, Color color) {
int period = random.nextInt(40) + 10; // 50;
boolean borderGap = true;
int frames = 20;
int phase = 7;
for (int i = 0; i < w1; i++) {
double d = (double) (period >> 1)
* Math.sin((double) i / (double) period
+ (6.2831853071795862D * (double) phase)
/ (double) frames);
g.copyArea(i, 0, 1, h1, 0, (int) d);
if (borderGap) {
g.setColor(color);
g.drawLine(i, (int) d, i, 0);
g.drawLine(i, (int) d + h1, i, h1);
}
}
}
}register.jsp
<tr>
<td>验证码</td>
<td class="inputs">
<input name="checkCode" type="text" id="checkCode">
<img id="checkCodeImg" src="/brand-demo/checkCodeServlet">
<a href="#" id="changeImg">看不清？</a>
</td>
</tr>
<script>
document.getElementById("changeImg").onclick = function () {
document.getElementById("checkCodeImg").src = "/brand-demo/checkCodeServlet?" + new Date().getMilliseconds();
};
document.getElementById("checkCodeImg").onclick = function () {
document.getElementById("checkCodeImg").src = "/brand-demo/checkCodeServlet?" + new Date().getMilliseconds();
};
</script>CheckCodeServlet.java
package com.ruochen.web;
import com.ruochen.utils.CheckCodeUtil;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 生成验证码
ServletOutputStream os = response.getOutputStream();
String checkCode = CheckCodeUtil.outputVerifyImage(100, 50, os, 4);
// 存入 session
HttpSession session = request.getSession();
session.setAttribute("checkCodeGen", checkCode);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}RegisterServlet.java
package com.ruochen.web;
import com.ruochen.pojo.User;
import com.ruochen.service.UserService;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {
private UserService service = new UserService();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1. 获取用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
User user = new User();
user.setUsername(username);
user.setPassword(password);
// 获取用户输入的验证码
String checkCode = request.getParameter("checkCode");
// 程序生成的验证码，从 session 获取
HttpSession session = request.getSession();
String checkCodeGen = (String) session.getAttribute("checkCodeGen");
// 比对
if (!checkCodeGen.equalsIgnoreCase(checkCode)) {
request.setAttribute("register_msg", "验证码错误");
request.getRequestDispatcher("/register.jsp").forward(request, response);
// 不允许注册
return;
}
// 2. 调用 service 注册
boolean flag = service.register(user);
// 3. 判断注册成功与否
if (flag) {
// 注册成功，跳转登录页面
request.setAttribute("register_msg", "注册成功，请登录");
request.getRequestDispatcher("/login.jsp").forward(request, response);
} else {
// 注册失败，跳转到注册页面
request.setAttribute("register_msg", "用户名已存在");
request.getRequestDispatcher("/register.jsp").forward(request, response);
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}测试
业务 - 登录验证
LoginFilter
package com.ruochen.web.filter;
import javax.servlet.*;
import javax.servlet.annotation.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import java.io.IOException;
/**
* 登录验证的过滤器
*/
@WebFilter("/*")
public class LoginFilter implements Filter {
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws ServletException, IOException {
HttpServletRequest req = (HttpServletRequest) request;
// 判断访问资源路径是否和登录注册相关
String[] urls = {"/login.jsp", "/imgs/", "/css/", "/loginServlet", "/register.jsp", "/registerServlet", "/checkCodeServlet"};
// 获取当前访问的资源路径
String url = req.getRequestURL().toString();
// 循环判断
for (String u : urls) {
if (url.contains(u)) {
// 包含
// 放行
chain.doFilter(request, response);
return;
}
}
// 1. 判断 session 中是否有 user
HttpSession session = req.getSession();
Object user = session.getAttribute("user");
// 2. 判断user是否为 null
if (user != null) {
// 已登录
// 放行
chain.doFilter(request, response);
} else {
// 未登录，存储提示信息，跳转到登录页面
req.setAttribute("login_msg", "您尚未登录！");
req.getRequestDispatcher("/login.jsp").forward(req, response);
}
}
public void init(FilterConfig config) throws ServletException {
}
public void destroy() {
}
}测试
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