第一步，在application.yml文件里面配置

server:
port: 9970

spring:
datasource:
url: jdbc:sqlserver://192.168.209.176:1433;DatabaseName=master_data
username: db_master_data
password: 123456
driverClassName: com.microsoft.sqlserver.jdbc.SQLServerDriver
initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 1000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 30000
validationQuery: select 'x'
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
maxPoolPreparedStatementPerConnectionSize: 20
filters: stat,wall,slf4j
connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000

mybatis:
mapper-locations: classpath:mapping/*Mapper.xml
type-aliases-package: com.aoyuan.entity

第二部，增加一个config的配置文件，这里使用阿里的druid连接池

package com.aoyuan.utils;
import java.sql.SQLException;

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;

import com.alibaba.druid.pool.DruidDataSource;

/**
* 数据源配置
* @author Administrator
*
*/
@Configuration
public class DruidConfiguration {

@Value("${spring.datasource.url}")
private String url;

@Value("${spring.datasource.username}")
private String username;

@Value("${spring.datasource.password}")
private String password;

@Value("${spring.datasource.driverClassName}")
private String driverClassName;

@Value("${spring.datasource.initialSize}")
private int initialSize;

@Value("${spring.datasource.minIdle}")
private int minIdle;

@Value("${spring.datasource.maxActive}")
private int maxActive;

@Value("${spring.datasource.maxWait}")
private int maxWait;

@Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
private int timeBetweenEvictionRunsMillis;

@Value("${spring.datasource.minEvictableIdleTimeMillis}")
private int minEvictableIdleTimeMillis;

@Value("${spring.datasource.validationQuery}")
private String validationQuery;

@Value("${spring.datasource.testWhileIdle}")
private boolean testWhileIdle;

@Value("${spring.datasource.testOnBorrow}")
private boolean testOnBorrow;

@Value("${spring.datasource.testOnReturn}")
private boolean testOnReturn;

@Value("${spring.datasource.poolPreparedStatements}")
private boolean poolPreparedStatements;

@Value("${spring.datasource.maxPoolPreparedStatementPerConnectionSize}")
private int maxPoolPreparedStatementPerConnectionSize;

@Value("${spring.datasource.filters}")
private String filters;

@Value("{spring.datasource.connectionProperties}")
private String connectionProperties;

@Bean
@Primary
public DataSource dataSource() {
DruidDataSource datasource = new DruidDataSource();

datasource.setUrl(url);
datasource.setUsername(username);
datasource.setPassword(password); //这里可以做加密处理
datasource.setDriverClassName(driverClassName);

//configuration
datasource.setInitialSize(initialSize);
datasource.setMinIdle(minIdle);
datasource.setMaxActive(maxActive);
datasource.setMaxWait(maxWait);
datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
datasource.setValidationQuery(validationQuery);
datasource.setTestWhileIdle(testWhileIdle);
datasource.setTestOnBorrow(testOnBorrow);
datasource.setTestOnReturn(testOnReturn);
datasource.setPoolPreparedStatements(poolPreparedStatements);
datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
try {
datasource.setFilters(filters);
} catch (SQLException e) {

}
datasource.setConnectionProperties(connectionProperties);

return datasource;
}

}

第三步，要在启动类上面加一个注解， mapperScan

@SpringBootApplication(scanBasePackages="com.aoyuan")
@MapperScan("com.aoyuan.dao")
public class RunApplication {
public static void main(String[] args) {
SpringApplication.run(RunApplication.class, args);
}
}