SpringBoot入门

1.导入maven包

<parent>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-parent</artifactId>
	<version>1.4.3.RELEASE</version>
</parent>
<!-- jdk版本 -->
<properties>
	<java.version>1.8</java.version>
</properties>

<dependencies>
	<!-- springboot启动器 -->
	<dependency>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-web</artifactId>
	</dependency>

	<!-- jdbc驱动 -->
	<dependency>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-jdbc</artifactId>
	</dependency>

	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
	</dependency>

	<!-- mybatis集成springboot -->
	<dependency>
		<groupId>org.mybatis.spring.boot</groupId>
		<artifactId>mybatis-spring-boot-starter</artifactId>
		<version>1.2.0</version>
	</dependency>
	
</dependencies>
<!-- maven支持插件 -->
<build>
	<plugins>
		<plugin>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-maven-plugin</artifactId>
		</plugin>
	</plugins>
</build>

2.在resources根目录下配置application.propertie或者application.yml

建议使用yml,因为yml具有层次感,也是比较潮流的

 # mysql四大金刚
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis
spring.datasource.username=root
spring.datasource.password=

# 配置xml的路径
mybatis.mapper-locations=classpath*:cn/itsource/mapperr/*.xml
# 实体类的别名
mybatis.type-aliases-package=cn.itsource.model

3.新建cn.itsource包,然后在写一个Application.java文件

@SpringBootApplication
public class Application implements CommandLineRunner {

	@Autowired
	private CountryMapper countryMapper;
	
	public static void main(String[] args) {
		SpringApplication.run(Application.class, args);
	}

//实现CommandLineRunner 接口,重写的方法会在tomcat启动之后立即运行
	@Override
public void run(String... args) throws Exception {
	List<Country> selectAll = countryMapper.selectAll();
	for (Country country : selectAll) {
		System.out.println(country);
		
	}
}

4.新建cn.itsource.model,并写一个实体类Country.java

public class Country {
	private Long id;
	private String countryname;
	private String countrycode;
	//getter setter

}

5.新建cn.itsource.mapper包并写CountryMapper.java

@mapper就会自动扫描,如果是@repository或者@service或者是@component@controller,那么就需要在Application启动类上配置扫描注解@MapperScan(“cn.itsource.mapper”)

		@Mapper
		public interface CountryMapper {
			/**
			 * 查询全部数据
			 * 
			 * @return
			 */
			List<Country> selectAll();
		}

6.早resources下面创建cn.itsource.mapper并创建映CountryMapper.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="tk.mybatis.springboot.mapper.CountryMapper">
	<select id="selectAll" resultType="Country">
		select id,countryname,countrycode from country
	</select>
</mapper>

7.最后在mysql里面新建一个数据库mybatis并新建一张表country,添加数据,然后启动Application里面的main方法,然后就能打印出来