（1）SpringBoot 2.X 集成Mybatis和Druid数据源

1.集成Mybatis

1.pom.xml中添加依赖

    <dependency>
      <groupId>org.mybatis.spring.bootgroupId>
      <artifactId>mybatis-spring-boot-starterartifactId>
      <version>1.3.1version>
    dependency>
    
    <dependency>
      <groupId>mysqlgroupId>
      <artifactId>mysql-connector-javaartifactId>
    dependency>

2.application.properties中添加配置

#mybatis
mybatis.type-aliases-package=com.lhj.miaosha.domain
mybatis.configuration.map-underscore-to-camel-case=true
mybatis.configuration.default-fetch-size=100
mybatis.configuration.default-statement-timeout=3000
mybatis.mapperLocations = classpath:com/lhj/miaosha/dao/*.xml

2. 集成Druid数据源

1.pom.xml中添加依赖

    
    <dependency>
      <groupId>com.alibabagroupId>
      <artifactId>druidartifactId>
      <version>1.1.10version>
    dependency>

2.application.properties中添加配置，更多配置

#JDBC配置
spring.datasource.url=jdbc:mysql://47.103.118.58:3306/miaosha?useAffectedRows=true&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&useSSL=false
spring.datasource.username=username
spring.datasource.password=pass
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

#连接池配置
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.filters=stat
spring.datasource.maxActive=1000
spring.datasource.initialSize=100
spring.datasource.maxWait=60000
spring.datasource.minIdle=500
spring.datasource.timeBetweenEvictionRunsMillis=60000
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery=select 'x'
spring.datasource.testWhileIdle=true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn=false
spring.datasource.poolPreparedStatements=true
spring.datasource.maxOpenPreparedStatements=20

3.代码

1.Dao层

@Mapper
public interface UserDao {
	
	@Select("select * from user where id = #{id}")
	public User getById(@Param("id")int id	);

	@Insert("insert into user(id, name)values(#{id}, #{name})")
	public int insert(User user);
	
}

2.Service层

@Service
public class UserService {
	/**
	 *测试查询
	 */
	@Autowired
	UserDao userDao;
	
	public User getById(int id) {
		 return userDao.getById(id);
	}
	/**
	 *测试事务
	 */
	@Transactional
	public boolean tx() {
		User u1= new User();
		u1.setId(2);
		u1.setName("2222");
		userDao.insert(u1);
		
		User u2= new User();
		u2.setId(1);
		u2.setName("11111");
		userDao.insert(u2);
		return true;
	}	
}

3.View层

@Controller
@RequestMapping("/demo")
public class SampleController {

	@Autowired
	UserService userService;
	
    @RequestMapping("/db/get")
    @ResponseBody
    public Result<User> dbGet() {
    	User user = userService.getById(1);
        return Result.success(user);
    }
    @RequestMapping("/db/tx")
    @ResponseBody
    public Result<Boolean> dbTx() {
    	userService.tx();
        return Result.success(true);
    }
}

4.User对象

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

    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;
    }
}