快速入门

快速入门

第一步：添加jar包

<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/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.hous.spring</groupId>
	<artifactId>mybatis-1</artifactId>
	<packaging>war</packaging>
	<version>0.0.1-SNAPSHOT</version>
	<name>mybatis-1 Maven Webapp</name>
	<url>http://maven.apache.org</url>
	<dependencies>
		<dependency>
			<groupId>org.mybatis</groupId>
			<artifactId>mybatis</artifactId>
			<version>3.2.8</version>
		</dependency>

		<!-- 添加mysql驱动包 -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>5.1.30</version>
		</dependency>
		<!-- 单元测试 -->
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.11</version>
			<scope>test</scope>
		</dependency>
	</dependencies>
	<build>
		<finalName>mybatis-1</finalName>
	</build>
	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>3.1</version>
				<type>maven-plugin</type>
				<configuration>
					<source>1.7</source>
					<target>1.7</target>
				</configuration>
			</dependency>
		</dependencies>
	</dependencyManagement>
</project>

 第二步：创建数据库和表，并添加数据

create database mybatis;
use mybatis;
create table users(
id int primary key auto_increment,
name varchar(20),
age int
);
insert into users(name, age) values('hous', 11),('geny',12);

 第三步：添加mybatis对应的配置文件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>
	<!-- 
		development:开发模式
		work：工作模式
	 -->
	<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://localhost:3306/mybatis" />
				<property name="username" value="root" />
				<property name="password" value="root" />
			</dataSource>
		</environment>
	</environments>
	<mappers>
		<mapper resource="com/hous/day1/userMapper.xml" />
	</mappers>

</configuration>

 第四步：定义表所对应实体类

package com.hous.day1;

public class User {
	private int id;
	private String name;
	private int age;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
	}

}

 第五步：定义操作users表的sql映射文件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.hous.day1.userMapper">
	<!-- 根据id查询到一个对象 -->
	<select id="getUser" parameterType="int" 
		resultType="com.hous.day1.User">
		select * from users where id=#{id}
	</select>
</mapper>

 第六步：在config.xml注册userMapper.xml文件

<mappers>
	<mapper resource="com/hous/day1/userMapper.xml" />
</mappers>

 第七步：编写测试代码，执行定义的select语句

package com.hous.day1;

import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class Test {
	public static void main(String[] args) throws IOException {
		String resource = "day1/config.xml";
		// 加载mybatis的配置文件（它也加载关联的映射文件）
//		Reader reader = Resources.getResourceAsReader(resource);
		InputStream is = Test.class.getClassLoader().getResourceAsStream(resource);
		// 构建sqlSession的工厂
		SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(is);
		// 创建能执行映射文件中sql的sqlSession
		SqlSession session = sessionFactory.openSession();
		// 映射sql的标识字符串
		String statement = "com.hous.day1.userMapper" + ".getUser";
		// 执行查询返回一个唯一user对象的sql
		User user = session.selectOne(statement, 3);
		System.out.println(user);
	}

}