javaweb 黑马 用时最短，知识最全
1-10节课
12
分組查詢
/*
分组函数
SELECT 字段列表 FROM 表名 [WHERE 分组前条件限定] GROUP BY 分组字段名 [HAVING 分组后条件过滤]…;
*/
select * from stu ;
-- 1. 查询男同学和女同学各自的数学平均分
select sex, avg(math) from stu group by sex;
-- 注意：分组之后，查询的字段为聚合函数和分组字段，查询其他字段无任何意义
select name, sex, avg(math) from stu group by sex;
-- 2. 查询男同学和女同学各自的数学平均分，以及各自人数
select sex, avg(math),count(*) from stu group by sex;
-- 3. 查询男同学和女同学各自的数学平均分，以及各自人数，要求：分数低于70分的不参与分组
select sex, avg(math),count(*) from stu where math > 70 group by sex;
-- 4. 查询男同学和女同学各自的数学平均分，以及各自人数，要求：分数低于70分的不参与分组，分组之后人数大于2个的。
select sex, avg(math),count(*) from stu where math > 70 group by sex having count(*) > 2;
/*
分页查询:
SELECT 字段列表 FROM 表名 LIMIT 起始索引 , 查询条目数
* 起始索引：从0开始
*/
select * from stu ;
-- 1. 从0开始查询，查询3条数据
select * from stu limit 0 , 3;
-- 2. 每页显示3条数据，查询第1页数据
select * from stu limit 0 , 3;
-- 3. 每页显示3条数据，查询第2页数据
select * from stu limit 3 , 3;
-- 4. 每页显示3条数据，查询第3页数据
select * from stu limit 6 , 3;
-- 起始索引 = （当前页码 - 1） * 每页显示的条数
约束
多表查询
事务
30JDBC
package com.itheima.jdbc;
import com.mysql.jdbc.Driver;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class Jdbcdemo {
public static void main(String[] args) throws Exception {
//1. 注册驱动
//Class.forName("com.mysql.jdbc.Driver"); //可以省略不写
//2. 获取连接
String url = "jdbc:mysql://127.0.0.1:3306/db1?useSSL=false";
String username = "root";
String password = "mysql";
Connection conn = DriverManager.getConnection(url, username, password);
//3. 定义sql
String sql = "update tb_user set username1='stu' WHERE id =2;";
//4. 获取执行sql的对象 Statement
Statement stmt = conn.createStatement();
//5. 执行sql
int count = stmt.executeUpdate(sql);//受影响的行数
//6. 处理结果
System.out.println(count);
//7. 释放资源
stmt.close();
conn.close();
}
}
如果连接本机，并且端口是3306，ip和端口可以不写
String url = “jdbc:mysql:///db1”;
32 connection
package com.itheima.jdbc;
import com.mysql.jdbc.Driver;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
public class Jdbcdemo {
public static void main(String[] args) throws Exception {
//1. 注册驱动
//Class.forName("com.mysql.jdbc.Driver");
//2. 获取连接
String url = "jdbc:mysql://127.0.0.1:3306/db1?useSSL=false";
String username = "root";
String password = "mysql";
Connection conn = DriverManager.getConnection(url, username, password);
//3. 定义sql
String sql1 = "update tb_user set username1='s1' WHERE id =1;";
String sql2 = "update tb_user set username1='stu2' WHERE id =2;";
//4. 获取执行sql的对象 Statement
Statement stmt = conn.createStatement();
try {
//开始事务
conn.setAutoCommit(false);
//5. 执行sql
int count1 = stmt.executeUpdate(sql1);//受影响的行数
int count2 = stmt.executeUpdate(sql2);//受影响的行数
//6. 处理结果
System.out.println(count1);
System.out.println(count2);
//提交事务
conn.commit();
} catch (Exception e) {
//回滚事务
conn.rollback();
e.printStackTrace();
}
//7. 释放资源
stmt.close();
conn.close();
}
}
如果try语句中出现异常，事务会回滚。
33
34 resultset
package com.itheima.jdbc;
import com.itheima.pojo.Account;
import org.testng.annotations.Test;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
/**
* JDBC API 详解：ResultSet
*/
public class JDBCDemo5_ResultSet {
/**
* 执行DQL
* @throws Exception
*/
@Test
public void testResultSet() throws Exception {
//1. 注册驱动
//Class.forName("com.mysql.jdbc.Driver");
//2. 获取连接：如果连接的是本机mysql并且端口是默认的 3306 可以简化书写
String url = "jdbc:mysql:///db1?useSSL=false";
String username = "root";
String password = "mysql";
Connection conn = DriverManager.getConnection(url, username, password);
//3. 定义sql
String sql = "select * from account";
//4. 获取statement对象
Statement stmt = conn.createStatement();
//5. 执行sql
ResultSet rs = stmt.executeQuery(sql);
//6. 处理结果， 遍历rs中的所有数据
/* // 6.1 光标向下移动一行，并且判断当前行是否有数据
while (rs.next()){
//6.2 获取数据 getXxx()
int id = rs.getInt(1);
String name = rs.getString(2);
double money = rs.getDouble(3);
System.out.println(id);
System.out.println(name);
System.out.println(money);
System.out.println("--------------");
}*/
// 6.1 光标向下移动一行，并且判断当前行是否有数据
while (rs.next()){
//6.2 获取数据 getXxx()
int id = rs.getInt("id");
String name = rs.getString("name");
double money = rs.getDouble("money");
System.out.println(id);
System.out.println(name);
System.out.println(money);
System.out.println("--------------");
}
//7. 释放资源
rs.close();
stmt.close();
conn.close();
}
/**
* 查询account账户表数据，封装为Account对象中，并且存储到ArrayList集合中
* 1. 定义实体类Account
* 2. 查询数据，封装到Account对象中
* 3. 将Account对象存入ArrayList集合中
*
*
* @throws Exception
*/
@Test
public void testResultSet2() throws Exception {
//1. 注册驱动
//Class.forName("com.mysql.jdbc.Driver");
//2. 获取连接：如果连接的是本机mysql并且端口是默认的 3306 可以简化书写
String url = "jdbc:mysql://127.0.0.1:3306/db1?useSSL=false";
String username = "root";
String password = "mysql";
Connection conn = DriverManager.getConnection(url, username, password);
//3. 定义sql
String sql = "select * from account";
//4. 获取statement对象
Statement stmt = conn.createStatement();
//5. 执行sql
ResultSet rs = stmt.executeQuery(sql);
// 创建集合
List<Account> list = new ArrayList<>();
// 6.1 光标向下移动一行，并且判断当前行是否有数据
while (rs.next()){
Account account = new Account();
//6.2 获取数据 getXxx()
int id = rs.getInt("id");
String name = rs.getString("name");
double money = rs.getDouble("money");
//赋值
account.setId(id);
account.setName(name);
account.setMoney(money);
// 存入集合
list.add(account);
}
System.out.println(list);
//7. 释放资源
rs.close();
stmt.close();
conn.close();
}
}
打印的集合对象
[Account{id=1, name=‘张三’, money=100.0}, Account{id=2, name=‘李四’, money=200.02}]
把数据库中的数据存入 对象，把对象存入集合，后期显示在前端页面
35
preparedStatement 防止sql注入
package com.itheima.jdbc;
//import org.junit.Test;
import org.testng.annotations.Test;
import java.sql.*;
import java.util.Date;
/**
* API详解：PreparedStatement
*/
public class JDBCDemo7_PreparedStatement {
@Test
public void test() throws SQLException {
String url = "jdbc:mysql:///db1?useSSL=false";
String username = "root";
String password = "mysql";
Connection conn = DriverManager.getConnection(url, username, password);
// 接收用户输入 用户名和密码
String name = "zhangsan";
String pwd = "123";
// 定义sql
String sql = "select * from tb_user where username = '"+name+"' and password = '"+pwd+"'";
Statement statement = conn.createStatement();
ResultSet rs = statement.executeQuery(sql);
// 判断登录是否成功
if(rs.next()){
System.out.println("登录成功~");
}else{
System.out.println("登录失败~");
}
//7. 释放资源
rs.close();
statement.close();
conn.close();
}
@Test
public void testPreparedStatement() throws Exception {
//2. 获取连接：如果连接的是本机mysql并且端口是默认的 3306 可以简化书写
String url = "jdbc:mysql:///db1?useSSL=false";
String username = "root";
String password = "mysql";
Connection conn = DriverManager.getConnection(url, username, password);
// 接收用户输入 用户名和密码
String name = "zhangsan";
String pwd = "' or '1' = '1";
// 定义sql
String sql = "select * from tb_user where username = ? and password = ?";
// 获取pstmt对象
PreparedStatement pstmt = conn.prepareStatement(sql);
// 设置？的值,此时参数注入失败
pstmt.setString(1,name);
pstmt.setString(2,pwd);
// 执行sql
ResultSet rs = pstmt.executeQuery();
// 判断登录是否成功
if(rs.next()){
System.out.println("登录成功~");
}else{
System.out.println("登录失败~");
}
//7. 释放资源
rs.close();
pstmt.close();
conn.close();
}
/**
* PreparedStatement原理
* @throws Exception
*/
@Test
public void testPreparedStatement2() throws Exception {
//2. 获取连接：如果连接的是本机mysql并且端口是默认的 3306 可以简化书写
// useServerPrepStmts=true 参数开启预编译功能
String url = "jdbc:mysql:///db1?useSSL=false&useServerPrepStmts=true";
String username = "root";
String password = "1234";
Connection conn = DriverManager.getConnection(url, username, password);
// 接收用户输入 用户名和密码
String name = "zhangsan";
String pwd = "' or '1' = '1";
// 定义sql
String sql = "select * from tb_user where username = ? and password = ?";
// 获取pstmt对象
PreparedStatement pstmt = conn.prepareStatement(sql);
Thread.sleep(10000);
// 设置？的值
pstmt.setString(1,name);
pstmt.setString(2,pwd);
ResultSet rs = null;
// 执行sql
rs = pstmt.executeQuery();
// 设置？的值
pstmt.setString(1,"aaa");
pstmt.setString(2,"bbb");
// 执行sql
rs = pstmt.executeQuery();
// 判断登录是否成功
if(rs.next()){
System.out.println("登录成功~");
}else{
System.out.println("登录失败~");
}
//7. 释放资源
rs.close();
pstmt.close();
conn.close();
}
}
38–41数据库连接池
把jar包复制到lib文件下，as a libaray–moudle libaray
package com.itheima.druid;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import javax.sql.DataSource;
import java.io.FileInputStream;
import java.sql.Connection;
import java.util.Properties;
/**
* Druid数据库连接池演示
*/
public class DruidDemo {
public static void main(String[] args) throws Exception {
//1.导入jar包
//2.定义配置文件
//3. 加载配置文件
Properties prop = new Properties();
prop.load(new FileInputStream("jdbc-demo/src/druid.properties"));
//4. 获取连接池对象
DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);
//5. 获取数据库连接 Connection
Connection connection = dataSource.getConnection();
System.out.println(connection);
System.out.println(System.getProperty("user.dir"));
}
}
durid 数据连接配置
39
-- 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;
创建实体类小技巧：
ctrl+r 替换
alt+按住鼠标左键，整列编辑，选中列的多行光标移动，统一书写
实体类中建议使用包装类Integer 默认值null
package com.itheima.example;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.itheima.pojo.Brand;
import org.testng.annotations.Test;
import javax.sql.DataSource;
import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
/**
* 品牌数据的增删改查操作
*/
public class BrandTest {
/**
* 查询所有
* 1. SQL：select * from tb_brand;
* 2. 参数：不需要
* 3. 结果：List<Brand>
*/
@Test
public void testSelectAll() throws Exception {
//1. 获取Connection
//3. 加载配置文件
Properties prop = new Properties();
prop.load(new FileInputStream("../jdbc-demo/src/druid.properties"));
//4. 获取连接池对象
DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);
//5. 获取数据库连接 Connection
Connection conn = dataSource.getConnection();
//2. 定义SQL
String sql = "select * from tb_brand;";
//3. 获取pstmt对象
PreparedStatement pstmt = conn.prepareStatement(sql);
//4. 设置参数
//5. 执行SQL
ResultSet rs = pstmt.executeQuery();
//6. 处理结果 List<Brand> 封装Brand对象，装载List集合
Brand brand = null;
List<Brand> brands = new ArrayList<>();
while (rs.next()){
//获取数据
int id = rs.getInt("id");
String brandName = rs.getString("brand_name");
String companyName = rs.getString("company_name");
int ordered = rs.getInt("ordered");
String description = rs.getString("description");
int status = rs.getInt("status");
//封装Brand对象
brand = new Brand();
brand.setId(id);
brand.setBrandName(brandName);
brand.setCompanyName(companyName);
brand.setOrdered(ordered);
brand.setDescription(description);
brand.setStatus(status);
//装载集合
brands.add(brand);
}
System.out.println(brands);
//7. 释放资源
rs.close();
pstmt.close();
conn.close();
}
/**
* 添加
* 1. SQL：insert into tb_brand(brand_name, company_name, ordered, description, status) values(?,?,?,?,?);
* 2. 参数：需要，除了id之外的所有参数信息
* 3. 结果：boolean
*/
@Test
public void testAdd() throws Exception {
// 接收页面提交的参数
String brandName = "xipiao";
String companyName = "xiang";
int ordered = 1;
String description = "raodiqiu";
int status = 1;
//1. 获取Connection
//3. 加载配置文件
Properties prop = new Properties();
prop.load(new FileInputStream("../jdbc-demo/src/druid.properties"));
//4. 获取连接池对象
DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);
//5. 获取数据库连接 Connection
Connection conn = dataSource.getConnection();
//2. 定义SQL
String sql = "insert into tb_brand(brand_name, company_name, ordered, description, status) values(?,?,?,?,?);";
//3. 获取pstmt对象
PreparedStatement pstmt = conn.prepareStatement(sql);
//4. 设置参数
pstmt.setString(1,brandName);
pstmt.setString(2,companyName);
pstmt.setInt(3,ordered);
pstmt.setString(4,description);
pstmt.setInt(5,status);
//5. 执行SQL
int count = pstmt.executeUpdate(); // 影响的行数
//6. 处理结果
System.out.println(count > 0);
//7. 释放资源
pstmt.close();
conn.close();
}
/**
* 修改
* 1. SQL：
update tb_brand
set brand_name = ?,
company_name= ?,
ordered = ?,
description = ?,
status = ?
where id = ?
* 2. 参数：需要，所有数据
* 3. 结果：boolean
*/
@Test
public void testUpdate() throws Exception {
// 接收页面提交的参数
String brandName = "xx";
String companyName = "xpp";
int ordered = 1000;
String description = "rdqs";
int status = 1;
int id = 4;
//1. 获取Connection
//3. 加载配置文件
Properties prop = new Properties();
prop.load(new FileInputStream("../jdbc-demo/src/druid.properties"));
//4. 获取连接池对象
DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);
//5. 获取数据库连接 Connection
Connection conn = dataSource.getConnection();
//2. 定义SQL
String sql = " update tb_brand\n" +
" set brand_name = ?,\n" +
" company_name= ?,\n" +
" ordered = ?,\n" +
" description = ?,\n" +
" status = ?\n" +
" where id = ?";
//3. 获取pstmt对象
PreparedStatement pstmt = conn.prepareStatement(sql);
//4. 设置参数
pstmt.setString(1,brandName);
pstmt.setString(2,companyName);
pstmt.setInt(3,ordered);
pstmt.setString(4,description);
pstmt.setInt(5,status);
pstmt.setInt(6,id);
//5. 执行SQL
int count = pstmt.executeUpdate(); // 影响的行数
//6. 处理结果
System.out.println(count > 0);
//7. 释放资源
pstmt.close();
conn.close();
}
/**
* 删除
* 1. SQL：
delete from tb_brand where id = ?
* 2. 参数：需要，id
* 3. 结果：boolean
*/
@Test
public void testDeleteById() throws Exception {
// 接收页面提交的参数
int id = 4;
//1. 获取Connection
//3. 加载配置文件
Properties prop = new Properties();
prop.load(new FileInputStream("jdbc-demo/src/druid.properties"));
//4. 获取连接池对象
DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);
//5. 获取数据库连接 Connection
Connection conn = dataSource.getConnection();
//2. 定义SQL
String sql = " delete from tb_brand where id = ?";
//3. 获取pstmt对象
PreparedStatement pstmt = conn.prepareStatement(sql);
//4. 设置参数
pstmt.setInt(1,id);
//5. 执行SQL
int count = pstmt.executeUpdate(); // 影响的行数
//6. 处理结果
System.out.println(count > 0);
//7. 释放资源
pstmt.close();
conn.close();
}
}
maven概述-1
maven安装及使用-3
45 配置maven
mybatis
48
日志依赖
<!-- 添加slf4j日志api -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.20</version>
</dependency>
<!-- 添加logback-classic依赖 -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.3</version>
</dependency>
<!-- 添加logback-core依赖 -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.2.3</version>
</dependency>
create database mybatis;
use mybatis;
drop table if exists tb_user;
create table tb_user(
id int primary key auto_increment,
username varchar(20),
password varchar(20),
gender char(1),
addr varchar(30)
);
INSERT INTO tb_user VALUES (1, 'zhangsan', '123', '男', '北京');
INSERT INTO tb_user VALUES (2, '李四', '234', '女', '天津');
INSERT INTO tb_user VALUES (3, '王五', '11', '男', '西安');
mapper代理
1mapper接口和sql映射文件在一起
2
3
4
细节
mybatis核心配置文件
配置了别名后，就会以包扫描的形式进行，usermapper中的resultType可以以pojo下的实体类命名，user不区分大小写
mybatis 代理开发示例代码如下：
UserMapper
package com.itheima.mapper;
import com.itheima.pojo.User;
import java.util.List;
public interface UserMapper {
List<User> selectAll();
}
User实体类
package com.itheima.pojo;
public class User {
private Integer id;
private String username;
private String password;
private String gender;
private String addr;
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;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getAddr() {
return addr;
}
public void setAddr(String addr) {
this.addr = addr;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
", gender='" + gender + '\'' +
", addr='" + addr + '\'' +
'}';
}
}
MybatisDemo2
package com.itheima;
import com.itheima.mapper.UserMapper;
import com.itheima.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 java.io.IOException;
import java.io.InputStream;
import java.util.List;
//mapper代理开发
public class MybatisDemo2 {
public static void main(String[] args) throws IOException {
//1. 加载mybatis的核心配置文件，获取 SqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2. 获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
//3.1获取usermapper接口的代理对象
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
List<User> users = userMapper.selectAll();
System.out.println(users);
//4. 释放资源
sqlSession.close();
}
}
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.itheima.mapper.UserMapper">
<select id="selectAll" resultType="com.itheima.pojo.User">
select *
from tb_user;
</select>
resultType使用别名需要在mybatis-config里配置别名
<select id="select" resultType="user">
select *
from tb_user
where
username = #{arg0}
and password = #{param2}
</select>
</mapper>
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>
<typeAliases>
<package name="com.itheima.pojo"/>
</typeAliases>
<!-- environments：配置数据库连接环境信息。可以配置多个environment，通过default属性切换不同的environment-->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<!--数据库连接信息-->
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql:///mybatis?useSSL=false"/>
<property name="username" value="root"/>
<property name="password" value="mysql"/>
</dataSource>
</environment>
</environments>
<mappers>
<!--Mapper代理方式-->
<package name="com.itheima.mapper"/>
</mappers>
</configuration>
logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appender name="Console" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>[%level] %cyan([%thread]) %boldGreen(%logger{15}) - %msg %n</pattern>
</encoder>
</appender>
<logger name="com.itheima" level="DEBUG" additivity="false">
<appender-ref ref="Console"/>
</logger>
<!--
level:用来设置打印级别，大小写无关：TRACE, DEBUG, INFO, WARN, ERROR, ALL 和 OFF
， 默认debug
<root>可以包含零个或多个<appender-ref>元素，标识这个输出位置将会被本日志级别控制。
-->
<root level="DEBUG">
<appender-ref ref="Console"/>
</root>
</configuration>
52mybatis实例
53查询所有和结果映射
<mapper namespace="com.itheima.mapper.BrandMapper">
<!--
数据库表的字段名称 和 实体类的属性名称 不一样，则不能自动封装数据
* 起别名：对不一样的列名起别名，让别名和实体类的属性名一样
* 缺点：每次查询都要定义一次别名
* sql片段
* 缺点：不灵活
* resultMap：
1. 定义<resultMap>标签
2. 在<select>标签中，使用resultMap属性替换 resultType属性
-->
<!--
id：唯一标识
type：映射的类型，支持别名
-->
<resultMap id="brandResultMap" type="brand">
<!--
id：完成主键字段的映射
column：表的列名
property：实体类的属性名
result：完成一般字段的映射
column：表的列名
property：实体类的属性名
-->
<result column="brand_name" property="brandName"/>
<result column="company_name" property="companyName"/>
</resultMap>
<select id="selectAll" resultMap="brandResultMap"> select * from tb_brand; </select>
<!--
sql片段
-->
<!--
<sql id="brand_column">
id, brand_name as brandName, company_name as companyName, ordered, description, status
</sql>
<select id="selectAll" resultType="brand">
select
<include refid="brand_column" />
from tb_brand;
</select>
-->
<!-- <select id="selectAll" resultType="brand">
select *
from tb_brand;
</select> -->
<!--
* 参数占位符：
1. #{}:会将其替换为 ?，为了防止SQL注入
2. ${}：拼sql。会存在SQL注入问题
3. 使用时机：
* 参数传递的时候：#{}
* 表名或者列名不固定的情况下：${} 会存在SQL注入问题
* 参数类型：parameterType：可以省略
* 特殊字符处理：
1. 转义字符：
2. CDATA区:
-->
<!-- <select id="selectById" resultMap="brandResultMap">
select *
from tb_brand where id = #{id};
</select>
-->
<select id="selectById" resultMap="brandResultMap">
select * from tb_brand where id
<![CDATA[ < ]]>
#{id};
</select>
<!--
条件查询
-->
<!-- <select id="selectByCondition" resultMap="brandResultMap">
select *
from tb_brand
where status = #{status}
and company_name like #{companyName}
and brand_name like #{brandName}
</select> -->
<!--
动态条件查询
* if: 条件判断
* test：逻辑表达式
* 问题：
* 恒等式
* <where> 替换 where 关键字
-->
<select id="selectByCondition" resultMap="brandResultMap">
select * from tb_brand /* where 1 = 1*/
<where>
<if test="status != null"> and status = #{status} </if>
<if test="companyName != null and companyName != '' "> and company_name like #{companyName} </if>
<if test="brandName != null and brandName != '' "> and brand_name like #{brandName} </if>
</where>
</select>
<!-- <select id="selectByConditionSingle" resultMap="brandResultMap">
select *
from tb_brand
where
<choose><!–相当于switch–>
<when test="status != null"><!–相当于case–>
status = #{status}
</when>
<when test="companyName != null and companyName != '' "><!–相当于case–>
company_name like #{companyName}
</when>
<when test="brandName != null and brandName != ''"><!–相当于case–>
brand_name like #{brandName}
</when>
<otherwise>
1 = 1
</otherwise>
</choose>
</select> -->
<select id="selectByConditionSingle" resultMap="brandResultMap">
select * from tb_brand
<where>
<choose>
<!-- 相当于switch -->
<when test="status != null">
<!-- 相当于case -->
status = #{status}
</when>
<when test="companyName != null and companyName != '' ">
<!-- 相当于case -->
company_name like #{companyName}
</when>
<when test="brandName != null and brandName != ''">
<!-- 相当于case -->
brand_name like #{brandName}
</when>
</choose>
</where>
</select>
<insert id="add" useGeneratedKeys="true" keyProperty="id"> insert into tb_brand (brand_name, company_name, ordered, description, status) values (#{brandName}, #{companyName}, #{ordered}, #{description}, #{status}); </insert>
<update id="update">
update tb_brand
<set>
<if test="brandName != null and brandName != ''"> brand_name = #{brandName}, </if>
<if test="companyName != null and companyName != ''"> company_name = #{companyName}, </if>
<if test="ordered != null"> ordered = #{ordered}, </if>
<if test="description != null and description != ''"> description = #{description}, </if>
<if test="status != null"> status = #{status} </if>
</set>
where id = #{id};
</update>
<delete id="deleteById"> delete from tb_brand where id = #{id}; </delete>
<!--
mybatis会将数组参数，封装为一个Map集合。
* 默认：array = 数组
* 使用@Param注解改变map集合的默认key的名称
-->
<delete id="deleteByIds">
delete from tb_brand where id in
<foreach collection="array" item="id" separator="," open="(" close=")"> #{id} </foreach>
;
</delete>
</mapper>
54查详情
55条件查询
第一种处理方法
@Test
public void selectByCondition() throws IOException {
//接受参数
int status = 1;
String companyName="huawei";
String brandName="huawei";
//处理参数
companyName = "%"+companyName+"%";
brandName = "%"+brandName+"%";
//1获取sqlSessionFactory对象
//1. 加载mybatis的核心配置文件，获取 SqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2. 获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
//3.1获取usermapper接口的代理对象
BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//4执行方法
List<Brand> brands = brandMapper.selectByCondition(status, companyName, brandName);
System.out.println(brands);
//5释放资源
sqlSession.close();
}
第二第三种处理方法
@Test
public void selectByCondition2() throws IOException {
//接受参数
int status = 1;
String companyName="huawei";
String brandName="huawei";
//处理参数
companyName = "%"+companyName+"%";
brandName = "%"+brandName+"%";
//封装对象
/*Brand brand = new Brand();
brand.setStatus(status);
brand.setCompanyName(companyName);
brand.setBrandName(brandName);*/
HashMap map = new HashMap();
map.put("status",status);
map.put("companyName",companyName);
map.put("brandName",brandName);
//1获取sqlSessionFactory对象
//1. 加载mybatis的核心配置文件，获取 SqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2. 获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
//3.1获取usermapper接口的代理对象
BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//4执行方法
// List<Brand> brands = brandMapper.selectByCondition(brand);
List<Brand> brands = brandMapper.selectByCondition(map);
System.out.println(brands);
//5释放资源
sqlSession.close();
}
56动态条件查询
单条件动态查询
<!-- <select id="selectByConditionSingle" resultMap="brandResultMap">
select *
from tb_brand
where
<choose><!–相当于switch–>
<when test="status != null"><!–相当于case–>
status = #{status}
</when>
<when test="companyName != null and companyName != '' "><!–相当于case–>
company_name like #{companyName}
</when>
<when test="brandName != null and brandName != ''"><!–相当于case–>
brand_name like #{brandName}
</when>
<otherwise>
1 = 1
</otherwise>
</choose>
</select> -->
<select id="selectByConditionSingle" resultMap="brandResultMap">
select * from tb_brand
<where>
<choose>
<!-- 相当于switch -->
<when test="status != null">
<!-- 相当于case -->
status = #{status}
</when>
<when test="companyName != null and companyName != '' ">
<!-- 相当于case -->
company_name like #{companyName}
</when>
<when test="brandName != null and brandName != ''">
<!-- 相当于case -->
brand_name like #{brandName}
</when>
</choose>
</where>
</select>
57 添加功能
insert id="add" useGeneratedKeys="true" keyProperty="id"> insert into tb_brand (brand_name, company_name, ordered, description, status) values (#{brandName}, #{companyName}, #{ordered}, #{description}, #{status}); </insert>
<
修改全字段
@Test
public void testUpdate() throws IOException {
//接受参数
int status = 1;
String companyName="huawei2";
String brandName="huawei2";
String description="huawei2";
int ordered = 200;
int id = 5;
//封装对象
Brand brand = new Brand();
brand.setStatus(status);
brand.setCompanyName(companyName);
brand.setBrandName(brandName);
brand.setDescription(description);
brand.setOrdered(ordered);
brand.setId(id);
//1获取sqlSessionFactory对象
//1. 加载mybatis的核心配置文件，获取 SqlSessionFactory
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2. 获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession(true);
//3.1获取usermapper接口的代理对象
BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
//4执行方法
int count = brandMapper.update(brand);
System.out.println(count);
//5释放资源
sqlSession.close();
}
动态修改字段
58删除
批量删除
59参数传递
60注解开发
html css javascript
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<script>
window.alert("hello js");
document.write("hello2");
console.log("hello3");
</script>
</body>
</html>
81事件监听
<!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="#">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>
<tr>
<td>手机号</td>
<td class="inputs"><input name="tel" type="text" id="tel">
<br>
<span id="tel_err" class="err_msg" style="display: none">手机号格式有误</span>
</td>
</tr>
</table>
<div class="buttons">
<input value="注 册" type="submit" id="reg_btn">
</div>
<br class="clear">
</form>
</div>
<script>
//1. 验证用户名是否符合规则
//1.1 获取用户名的输入框
var usernameInput = document.getElementById("username");
//1.2 绑定onblur事件 失去焦点
usernameInput.onblur = checkUsername;
function checkUsername() {
//1.3 获取用户输入的用户名
var username = usernameInput.value.trim();
//1.4 判断用户名是否符合规则：长度 6~12,单词字符组成
var reg = /^\w{6,12}$/;
var flag = reg.test(username);
//var flag = username.length >= 6 && username.length <= 12;
if (flag) {
//符合规则
document.getElementById("username_err").style.display = 'none';
} else {
//不合符规则
document.getElementById("username_err").style.display = '';
}
return flag;
}
//1. 验证密码是否符合规则
//1.1 获取密码的输入框
var passwordInput = document.getElementById("password");
//1.2 绑定onblur事件 失去焦点
passwordInput.onblur = checkPassword;
function checkPassword() {
//1.3 获取用户输入的密码
var password = passwordInput.value.trim();
//1.4 判断密码是否符合规则：长度 6~12
var reg = /^\w{6,12}$/;
var flag = reg.test(password);
//var flag = password.length >= 6 && password.length <= 12;
if (flag) {
//符合规则
document.getElementById("password_err").style.display = 'none';
} else {
//不合符规则
document.getElementById("password_err").style.display = '';
}
return flag;
}
//1. 验证手机号是否符合规则
//1.1 获取手机号的输入框
var telInput = document.getElementById("tel");
//1.2 绑定onblur事件 失去焦点
telInput.onblur = checkTel;
function checkTel() {
//1.3 获取用户输入的手机号
var tel = telInput.value.trim();
//1.4 判断手机号是否符合规则：长度 11，数字组成，第一位是1
//var flag = tel.length == 11;
var reg = /^[1]\d{10}$/;
var flag = reg.test(tel);
if (flag) {
//符合规则
document.getElementById("tel_err").style.display = 'none';
} else {
//不合符规则
document.getElementById("tel_err").style.display = '';
}
return flag;
}
//1. 获取表单对象
var regForm = document.getElementById("reg-form");
//2. 绑定onsubmit 事件
regForm.onsubmit = function () {
//挨个判断每一个表单项是否都符合要求，如果有一个不合符，则返回false
var flag = checkUsername() && checkPassword() && checkTel();
return flag;
}
</script>
</body>
</html>
* {
margin: 0;
padding: 0;
list-style-type: none;
}
.reg-content{
padding: 30px;
margin: 3px;
}
a, img {
border: 0;
}
body {
background-image: url("../imgs/reg_bg_min.jpg") ;
text-align: center;
}
table {
border-collapse: collapse;
border-spacing: 0;
}
td, th {
padding: 0;
height: 90px;
}
.inputs{
vertical-align: top;
}
.clear {
clear: both;
}
.clear:before, .clear:after {
content: "";
display: table;
}
.clear:after {
clear: both;
}
.form-div {
background-color: rgba(255, 255, 255, 0.27);
border-radius: 10px;
border: 1px solid #aaa;
width: 424px;
margin-top: 150px;
margin-left:1050px;
padding: 30px 0 20px 0px;
font-size: 16px;
box-shadow: inset 0px 0px 10px rgba(255, 255, 255, 0.5), 0px 0px 15px rgba(75, 75, 75, 0.3);
text-align: left;
}
.form-div input[type="text"], .form-div input[type="password"], .form-div input[type="email"] {
width: 268px;
margin: 10px;
line-height: 20px;
font-size: 16px;
}
.form-div input[type="checkbox"] {
margin: 20px 0 20px 10px;
}
.form-div input[type="button"], .form-div input[type="submit"] {
margin: 10px 20px 0 0;
}
.form-div table {
margin: 0 auto;
text-align: right;
color: rgba(64, 64, 64, 1.00);
}
.form-div table img {
vertical-align: middle;
margin: 0 0 5px 0;
}
.footer {
color: rgba(64, 64, 64, 1.00);
font-size: 12px;
margin-top: 30px;
}
.form-div .buttons {
float: right;
}
input[type="text"], input[type="password"], input[type="email"] {
border-radius: 8px;
box-shadow: inset 0 2px 5px #eee;
padding: 10px;
border: 1px solid #D4D4D4;
color: #333333;
margin-top: 5px;
}
input[type="text"]:focus, input[type="password"]:focus, input[type="email"]:focus {
border: 1px solid #50afeb;
outline: none;
}
input[type="button"], input[type="submit"] {
padding: 7px 15px;
background-color: #3c6db0;
text-align: center;
border-radius: 5px;
overflow: hidden;
min-width: 80px;
border: none;
color: #FFF;
box-shadow: 1px 1px 1px rgba(75, 75, 75, 0.3);
}
input[type="button"]:hover, input[type="submit"]:hover {
background-color: #5a88c8;
}
input[type="button"]:active, input[type="submit"]:active {
background-color: #5a88c8;
}
.err_msg{
color: red;
padding-right: 170px;
}
#password_err,#tel_err{
padding-right: 195px;
}
#reg_btn{
margin-right:50px; width: 285px; height: 45px; margin-top:20px;
}
正则
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<script>
// 规则：单词字符，6~12
var reg = /^\w{6,12}$/;
var str = "abcccc";
var flag = reg.test(str);
alert(flag);
</script>
</body>
</html>
84web核心
88 tomcat
94servlet
95
package com.itheima.web;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import java.io.IOException;
@WebServlet("/demo1")
public class ServletDemo implements Servlet {
public void init(ServletConfig servletConfig) throws ServletException {
}
public ServletConfig getServletConfig() {
return null;
}
public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
System.out.println("servlet 启动");
}
public String getServletInfo() {
return null;
}
public void destroy() {
}
}
package com.itheima.web;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import java.io.IOException;
@WebServlet("/demo2")
public class ServletDemo2 implements Servlet {
public void init(ServletConfig servletConfig) throws ServletException {
System.out.println("inti-----------");
}
public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
System.out.println("servlet 启动");
}
public void destroy() {
}
public ServletConfig getServletConfig() {
return null;
}
public String getServletInfo() {
return null;
}
}
一个方法的变量在另外一个方法中返回，提升成员变量的作用域
package com.itheima.web;
import javax.servlet.*;
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("/demo4")
public class ServletDemo4 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
System.out.println("get--------------");
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
System.out.println("post---------------");
}
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="/tomcat-demo2/demo4" method="post">
<input name="username"><input type="submit">
</form>
</body>
</html>
myservlet
package com.itheima.web;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
public class MyHttpServlet implements Servlet {
public void init(ServletConfig servletConfig) throws ServletException {
}
public ServletConfig getServletConfig() {
return null;
}
public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {
//根据请求方式的不同，进行分别的处理
HttpServletRequest request = (HttpServletRequest) servletRequest;
//1获取请求方式
String method = request.getMethod();
//2判断
if ("GET".equals(method)){
//get方式的处理逻辑
doGet(servletRequest,servletResponse);
}else if ("POST".equals(method)){
//post方式处理逻辑
doPost(servletRequest,servletResponse);
}
}
protected void doPost(ServletRequest servletRequest, ServletResponse servletResponse) {
}
protected void doGet(ServletRequest servletRequest, ServletResponse servletResponse) {
}
public String getServletInfo() {
return null;
}
public void destroy() {
}
}
package com.itheima.web;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
@WebServlet("/demo6")
public class ServletDemo6 extends MyHttpServlet {
@Override
protected void doGet(ServletRequest servletRequest, ServletResponse servletResponse) {
System.out.println("get============");
}
@Override
protected void doPost(ServletRequest servletRequest, ServletResponse servletResponse) {
System.out.println("post============");
}
}
request
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="/tomcat-demo2/req1" method="post">
<input type="text" name="username">
<input type="password" name="password">
<input type="submit">
</form>
</body>
</html>
package com.itheima.web;
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.BufferedReader;
import java.io.IOException;
@WebServlet("/req1")
public class RequestDemo1 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String method = req.getMethod();
System.out.println("method"+method);
String contextPath = req.getContextPath();
System.out.println("contextPath"+contextPath);
StringBuffer url = req.getRequestURL();
System.out.println(url);
String uri = req.getRequestURI();
System.out.println(uri);
String queryString = req.getQueryString();
System.out.println(queryString);
String header = req.getHeader("user-agent");
System.out.println(header);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//获取post的请求体
//1获取字符输入流
BufferedReader br = req.getReader();
//2读数据
String readLine = br.readLine();
System.out.println(readLine);
}
}
package com.itheima.web;
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.BufferedReader;
import java.io.IOException;
import java.util.Map;
@WebServlet("/req2")
public class RequestDemo2 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//get请求逻辑
//1获取所有参数的map集合
Map<String, String[]> map = req.getParameterMap();
for (String key : map.keySet()) {
System.out.println(key+":");
//获取值
String[] values = map.get(key);
for (String value : values) {
System.out.println(value+",");
}
}
System.out.println("------------------");
//2根据key获取值
String[] hobbies = req.getParameterValues("hobby");
for (String hobby : hobbies) {
System.out.println(hobby);
}
//3根据key获取两个参数值
String username = req.getParameter("username");
String password = req.getParameter("password");
System.out.println(username);
System.out.println(password);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//post请求逻辑
this.doGet(req,resp);
}
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="/tomcat-demo2/req2" method="post">
<input type="text" name="username"> <br>
<input type="password" name="password"> <br>
<input type="checkbox" name="hobby" value="1"> 游泳
<input type="checkbox" name="hobby" value="2"> 爬山 <br>
<input type="submit">
</form>
</body>
</html>
get post 通用乱码解决方法
105
package com.itheima.web;
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.io.PrintWriter;
@WebServlet("/resp3")
public class ResponseDemo1 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
System.out.println("resp-----");
resp.setContentType("text/html;charset=utf-8");
//1获取字符输出流
PrintWriter writer = resp.getWriter();
//content-type
// resp.setHeader("content-type","text/html");
writer.write("你好");
writer.write("<h1>aaa</h1>");
//细节 流不需要关闭
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doGet(req,resp);
}
}
109用户登录案例
用户注册
UserMapper
package com.itheima.mapper;
import com.itheima.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(@Param("username") String username);
/**
* 添加用户
* @param user
*/
// @Insert("insert into tb_user values(null,#{username},#{password})")
void add(User user);
}
LoginServlet
package com.itheima.web;
import com.itheima.mapper.UserMapper;
import com.itheima.pojo.User;
import com.itheima.util.SqlSessionFactoryUtils;
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);*/
SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtils.getSqlSessionFactory();
//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释放为null
if(user != null){
// 登陆成功
writer.write("登陆成功");
}else {
// 登陆失败
writer.write("登陆失败");
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
RegisterServlet
package com.itheima.web;
import com.itheima.mapper.UserMapper;
import com.itheima.pojo.User;
import com.itheima.util.SqlSessionFactoryUtils;
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);*/
SqlSessionFactory sqlSessionFactory = SqlSessionFactoryUtils.getSqlSessionFactory();
//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. 判断用户对象释放为null
if( u == null){
// 用户名不存在，添加用户
userMapper.add(user);
// 提交事务
sqlSession.commit();
// 释放资源
sqlSession.close();
}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");
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
UserMapper
<?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.itheima.mapper.UserMapper">
<insert id="add">
insert into tb_user values(null,#{username},#{password})
</insert>
<select id="select" resultType="com.itheima.pojo.User">
select * from tb_user where username = #{username} and password = #{password}
</select>
<select id="selectByUsername" resultType="com.itheima.pojo.User">
select * from tb_user where username = #{username}
</select>
</mapper>
mybatis-config
<?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.itheima.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="mysql"/>
</dataSource>
</environment>
</environments>
<mappers>
<!--扫描mapper-->
<package name="com.itheima.mapper"/>
</mappers>
</configuration>
<!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="/request-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>
register
<!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="/request-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" 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>
package com.itheima.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;
}
}
代码路径码云：
https://gitee.com/lily3619/202310request-login
案例
119
120添加
121修改
122修改数据
代码路径：https://gitee.com/lily3619/brand-demo2
123会话跟踪技术
124
129
141 axios入门
142 json
143 json数据和java对象转换
144-145 案例
查询所有
新增品牌
项目路径：https://gitee.com/lily3619/axios-brand-demo
146vue
149 element
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>element-demo1</title>
</head>
<body>
<div id="app">
<el-row>
<el-button>默认按钮</el-button>
<el-button type="primary">主要按钮</el-button>
<el-button type="success">成功按钮</el-button>
<el-button type="info">信息按钮</el-button>
<el-button type="warning">警告按钮</el-button>
<el-button type="danger">危险按钮</el-button>
</el-row>
</div>
<script src="js/vue.js"></script>
<script src="element-ui/lib/index.js"></script>
<link rel="stylesheet" href="element-ui/lib/theme-chalk/index.css">
<script>
new Vue({
el:"#app"
})
</script>
</body>
</html>
layout布局
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>element-demo1</title>
<style>
.el-row {
margin-bottom: 20px;
&:last-child {
margin-bottom: 0;
}
}
.el-col {
border-radius: 4px;
}
.bg-purple-dark {
background: #99a9bf;
}
.bg-purple {
background: #d3dce6;
}
.bg-purple-light {
background: #e5e9f2;
}
.grid-content {
border-radius: 4px;
min-height: 36px;
}
.row-bg {
padding: 10px 0;
background-color: #f9fafc;
}
</style>
</head>
<body>
<div id="app">
<el-row>
<el-col :span="24">
<div class="grid-content bg-purple-dark"></div>
</el-col>
</el-row>
<el-row>
<el-col :span="12">
<div class="grid-content bg-purple"></div>
</el-col>
<el-col :span="12">
<div class="grid-content bg-purple-light"></div>
</el-col>
</el-row>
<el-row>
<el-col :span="8">
<div class="grid-content bg-purple"></div>
</el-col>
<el-col :span="8">
<div class="grid-content bg-purple-light"></div>
</el-col>
<el-col :span="8">
<div class="grid-content bg-purple"></div>
</el-col>
</el-row>
<el-row>
<el-col :span="6">
<div class="grid-content bg-purple"></div>
</el-col>
<el-col :span="6">
<div class="grid-content bg-purple-light"></div>
</el-col>
<el-col :span="6">
<div class="grid-content bg-purple"></div>
</el-col>
<el-col :span="6">
<div class="grid-content bg-purple-light"></div>
</el-col>
</el-row>
<el-row>
<el-col :span="4">
<div class="grid-content bg-purple"></div>
</el-col>
<el-col :span="4">
<div class="grid-content bg-purple-light"></div>
</el-col>
<el-col :span="4">
<div class="grid-content bg-purple"></div>
</el-col>
<el-col :span="4">
<div class="grid-content bg-purple-light"></div>
</el-col>
<el-col :span="4">
<div class="grid-content bg-purple"></div>
</el-col>
<el-col :span="4">
<div class="grid-content bg-purple-light"></div>
</el-col>
</el-row>
</div>
<script src="js/vue.js"></script>
<script src="element-ui/lib/index.js"></script>
<link rel="stylesheet" href="element-ui/lib/theme-chalk/index.css">
<script>
new Vue({
el:"#app"
})
</script>
</body>
</html>
containt布局
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.el-header {
background-color: #B3C0D1;
color: #333;
line-height: 60px;
}
.el-aside {
color: #333;
}
</style>
</head>
<body>
<div id="app">
<el-container style="height: 500px; border: 1px solid #eee">
<el-aside width="200px" style="background-color: rgb(238, 241, 246)">
<el-menu :default-openeds="['1', '3']">
<el-submenu index="1">
<template slot="title"><i class="el-icon-message"></i>导航一</template>
<el-menu-item-group>
<template slot="title">分组一</template>
<el-menu-item index="1-1">选项1</el-menu-item>
<el-menu-item index="1-2">选项2</el-menu-item>
</el-menu-item-group>
<el-menu-item-group title="分组2">
<el-menu-item index="1-3">选项3</el-menu-item>
</el-menu-item-group>
<el-submenu index="1-4">
<template slot="title">选项4</template>
<el-menu-item index="1-4-1">选项4-1</el-menu-item>
</el-submenu>
</el-submenu>
<el-submenu index="2">
<template slot="title"><i class="el-icon-menu"></i>导航二</template>
<el-menu-item-group>
<template slot="title">分组一</template>
<el-menu-item index="2-1">选项1</el-menu-item>
<el-menu-item index="2-2">选项2</el-menu-item>
</el-menu-item-group>
<el-menu-item-group title="分组2">
<el-menu-item index="2-3">选项3</el-menu-item>
</el-menu-item-group>
<el-submenu index="2-4">
<template slot="title">选项4</template>
<el-menu-item index="2-4-1">选项4-1</el-menu-item>
</el-submenu>
</el-submenu>
<el-submenu index="3">
<template slot="title"><i class="el-icon-setting"></i>导航三</template>
<el-menu-item-group>
<template slot="title">分组一</template>
<el-menu-item index="3-1">选项1</el-menu-item>
<el-menu-item index="3-2">选项2</el-menu-item>
</el-menu-item-group>
<el-menu-item-group title="分组2">
<el-menu-item index="3-3">选项3</el-menu-item>
</el-menu-item-group>
<el-submenu index="3-4">
<template slot="title">选项4</template>
<el-menu-item index="3-4-1">选项4-1</el-menu-item>
</el-submenu>
</el-submenu>
</el-menu>
</el-aside>
<el-container>
<el-header style="text-align: right; font-size: 12px">
<el-dropdown>
<i class="el-icon-setting" style="margin-right: 15px"></i>
<el-dropdown-menu slot="dropdown">
<el-dropdown-item>查看</el-dropdown-item>
<el-dropdown-item>新增</el-dropdown-item>
<el-dropdown-item>删除</el-dropdown-item>
</el-dropdown-menu>
</el-dropdown>
<span>王小虎</span>
</el-header>
<el-main>
<el-table :data="tableData">
<el-table-column prop="date" label="日期" width="140">
</el-table-column>
<el-table-column prop="name" label="姓名" width="120">
</el-table-column>
<el-table-column prop="address" label="地址">
</el-table-column>
</el-table>
</el-main>
</el-container>
</el-container>
</div>
<script src="js/vue.js"></script>
<script src="element-ui/lib/index.js"></script>
<link rel="stylesheet" href="element-ui/lib/theme-chalk/index.css">
<script>
new Vue({
el:"#app",
data() {
const item = {
date: '2016-05-02',
name: '王小虎',
address: '上海市普陀区金沙江路 1518 弄'
};
return {
tableData: Array(20).fill(item)
}
}
})
</script>
</body>
</html>
使用element-ui做一个前端页面示例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.el-table .warning-row {
background: oldlace;
}
.el-table .success-row {
background: #f0f9eb;
}
</style>
</head>
<body>
<div id="app">
<!--搜索表单-->
<el-form :inline="true" :model="brand" class="demo-form-inline">
<el-form-item label="当前状态">
<el-select v-model="brand.status" placeholder="当前状态">
<el-option label="启用" value="1"></el-option>
<el-option label="禁用" value="0"></el-option>
</el-select>
</el-form-item>
<el-form-item label="企业名称">
<el-input v-model="brand.companyName" placeholder="企业名称"></el-input>
</el-form-item>
<el-form-item label="品牌名称">
<el-input v-model="brand.brandName" placeholder="品牌名称"></el-input>
</el-form-item>
<el-form-item>
<el-button type="primary" @click="onSubmit">查询</el-button>
</el-form-item>
</el-form>
<!--按钮-->
<el-row>
<el-button type="danger" plain>批量删除</el-button>
<el-button type="primary" plain @click="dialogVisible = true">新增</el-button>
</el-row>
<!--添加数据对话框表单-->
<el-dialog
title="编辑品牌"
:visible.sync="dialogVisible"
width="30%"
>
<el-form ref="form" :model="brand" label-width="80px">
<el-form-item label="品牌名称">
<el-input v-model="brand.brandName"></el-input>
</el-form-item>
<el-form-item label="企业名称">
<el-input v-model="brand.companyName"></el-input>
</el-form-item>
<el-form-item label="排序">
<el-input v-model="brand.ordered"></el-input>
</el-form-item>
<el-form-item label="备注">
<el-input type="textarea" v-model="brand.description"></el-input>
</el-form-item>
<el-form-item label="状态">
<el-switch v-model="brand.status"
active-value="1"
inactive-value="0"
></el-switch>
</el-form-item>
<el-form-item>
<el-button type="primary" @click="addBrand">提交</el-button>
<el-button @click="dialogVisible = false">取消</el-button>
</el-form-item>
</el-form>
</el-dialog>
<!--表格-->
<template>
<el-table
:data="tableData"
style="width: 100%"
:row-class-name="tableRowClassName"
@selection-change="handleSelectionChange"
>
<el-table-column
type="selection"
width="55">
</el-table-column>
<el-table-column
type="index"
width="50">
</el-table-column>
<el-table-column
prop="brandName"
label="品牌名称"
align="center"
>
</el-table-column>
<el-table-column
prop="companyName"
label="企业名称"
align="center"
>
</el-table-column>
<el-table-column
prop="ordered"
align="center"
label="排序">
</el-table-column>
<el-table-column
prop="status"
align="center"
label="当前状态">
</el-table-column>
<el-table-column
align="center"
label="操作">
<el-row>
<el-button type="primary">修改</el-button>
<el-button type="danger">删除</el-button>
</el-row>
</el-table-column>
</el-table>
</template>
<!--分页工具条-->
<el-pagination
@size-change="handleSizeChange"
@current-change="handleCurrentChange"
:current-page="currentPage"
:page-sizes="[5, 10, 15, 20]"
:page-size="5"
layout="total, sizes, prev, pager, next, jumper"
:total="400">
</el-pagination>
</div>
<script src="js/vue.js"></script>
<script src="element-ui/lib/index.js"></script>
<link rel="stylesheet" href="element-ui/lib/theme-chalk/index.css">
<script>
new Vue({
el: "#app",
methods: {
tableRowClassName({row, rowIndex}) {
if (rowIndex === 1) {
return 'warning-row';
} else if (rowIndex === 3) {
return 'success-row';
}
return '';
},
// 复选框选中后执行的方法
handleSelectionChange(val) {
this.multipleSelection = val;
console.log(this.multipleSelection)
},
// 查询方法
onSubmit() {
console.log(this.brand);
},
// 添加数据
addBrand(){
console.log(this.brand);
},
//分页
handleSizeChange(val) {
console.log(`每页 ${val} 条`);
},
handleCurrentChange(val) {
console.log(`当前页: ${val}`);
}
},
data() {
return {
// 当前页码
currentPage: 4,
// 添加数据对话框是否展示的标记
dialogVisible: false,
// 品牌模型数据
brand: {
status: '',
brandName: '',
companyName: '',
id:"",
ordered:"",
description:""
},
// 复选框选中数据集合
multipleSelection: [],
// 表格数据
tableData: [{
brandName: '华为',
companyName: '华为科技有限公司',
ordered: '100',
status: "1"
}, {
brandName: '华为',
companyName: '华为科技有限公司',
ordered: '100',
status: "1"
}, {
brandName: '华为',
companyName: '华为科技有限公司',
ordered: '100',
status: "1"
}, {
brandName: '华为',
companyName: '华为科技有限公司',
ordered: '100',
status: "1"
}]
}
}
})
</script>
</body>
</html>
启动服务，登录http://localhost:8080/brand-case/selectAllServlet,可以查看后台数据
启动服务，登录http://localhost:8080/brand-case/brand.html，可以查看页面
条件查询会自动去掉第一个and
完整项目路径
https://gitee.com/lily3619/brandweb2
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