spring boot 通过mybatis连接MySQL数据库

在上篇中，已经创建好了boot的三个服务。现在在service-A中说明一下连接数据库的详细过程。

1.在pom.xml中加入

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-jdbcartifactId>
        dependency>
        
        <dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
            <version>1.3.0version>
        dependency>
        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
        dependency>
        
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druidartifactId>
            <version>1.1.1version>
        dependency>
        
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatisartifactId>
            <version>3.4.4version>
        dependency>
        <dependency>
            <groupId>org.mybatisgroupId>
            <artifactId>mybatis-springartifactId>
            <version>1.3.1version>
        dependency>

2.创建实体类Test.java

    /**
     * Created by qqg on 2017/9/19.
     */
    public class Test {
        private int id;
        private String name;
        private String password;
        @Override
        public String toString() {
            return "Test{" +
                    "id=" + id +
                    ", name='" + name + '\'' +
                    ", password='" + password + '\'' +
                    '}';
        }
        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 String getPassword() {
            return password;
        }
        public void setPassword(String password) {
            this.password = password;
        }
    }

3.创建mapper接口

import com.hand.dto.Test;
import java.util.List;
/**
 * Created by qqg on 2017/9/19.
 */
public interface TestMapper {
    List findAll();
}

4.创建service接口

import com.hand.dto.Test;
import org.springframework.stereotype.Service;
import java.util.List;
/**
 * Created by qqg on 2017/9/19.
 */
public interface ITestService {
    List findAll();
}

5.实现service接口

import com.hand.dto.Test;
import com.hand.mapper.TestMapper;
import com.hand.service.ITestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
/**
 * Created by qqg on 2017/9/19.
 */
@Service
public class TestServiceImpl implements ITestService {
    @Autowired
    private TestMapper mapper;
    @Override
    public List findAll() {
        return mapper.findAll();
    }
}

6.在配置文件resources下创建mapper文件夹，并在里面添加 TestMapper.xml文件。

TestMapper.xml 文件编写：

<mapper namespace="com.hand.mapper.TestMapper">
    <select id="findAll" resultType="com.hand.dto.Test">
        SELECT id,name,password from test
    select>
mapper>

7.resources下创建application.yml，并配置

server:
  port: 9092

spring:
  application:
    name: spring-cloud-consumer
  datasource:
    name: test
    url: jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf8
    username: root
    password: 123456
    #使用druid数据源  &useSSL=true
    type: com.alibaba.druid.pool.DruidDataSource
    driverClassName: com.mysql.jdbc.Driver
    filters: stat
    maxActive: 20
    initialSize: 1
    maxWait: 60000
    minIdle: 1
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: select 'x'
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
    maxOpenPreparedStatements: 20

mybatis:
  mapperLocations: classpath:mapper/*.xml  #指定*Mapper.xml的位置
#设置日志级别，打印mybatis的日志
logging:
  level:
    root: debug

8.1 mybatis映射文件类MybatisConfig

import com.alibaba.druid.pool.DruidDataSource;
import org.apache.ibatis.logging.LogFactory;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import javax.sql.DataSource;
/**
 * Created by qqg on 2017/9/19.
 */
@Configuration
public class MybatisConfig {
    /**
     * 注入环境变量的值
     */
    @Autowired
    private Environment environment;

    /**
     * 获取数据源DataSource
     * @return
     */
    @Bean
    public DataSource druidDataSource() {
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setUrl(environment.getProperty("spring.datasource.url"));
        druidDataSource.setUsername(environment.getProperty("spring.datasource.username"));
        druidDataSource.setPassword(environment.getProperty("spring.datasource.password"));
        druidDataSource.setDriverClassName(environment.getProperty("spring.datasource.driverClassName"));
        druidDataSource.setMaxActive(Integer.parseInt(environment.getProperty("spring.datasource.maxActive")));
        druidDataSource.setInitialSize(Integer.parseInt(environment.getProperty("spring.datasource.initialSize")));
        druidDataSource.setMaxWait(Long.parseLong(environment.getProperty("spring.datasource.maxWait")));
        druidDataSource.setMinIdle(Integer.parseInt(environment.getProperty("spring.datasource.minIdle")));
        druidDataSource.setTimeBetweenEvictionRunsMillis(Long.parseLong(environment.getProperty("spring.datasource.timeBetweenEvictionRunsMillis")));
        druidDataSource.setMinEvictableIdleTimeMillis(Long.parseLong(environment.getProperty("spring.datasource.minEvictableIdleTimeMillis")));
        druidDataSource.setValidationQuery(environment.getProperty("spring.datasource.validationQuery"));
        druidDataSource.setTestWhileIdle(Boolean.parseBoolean(environment.getProperty("spring.datasource.testWhileIdle")));
        druidDataSource.setTestOnBorrow(Boolean.parseBoolean(environment.getProperty("spring.datasource.testOnBorrow")));
        druidDataSource.setTestOnReturn(Boolean.parseBoolean(environment.getProperty("spring.datasource.testOnReturn")));
        druidDataSource.setPoolPreparedStatements(Boolean.parseBoolean(environment.getProperty("spring.datasource.poolPreparedStatements")));
       druidDataSource.setMaxOpenPreparedStatements(Integer.parseInt(environment.getProperty("spring.datasource.maxOpenPreparedStatements")));
        return druidDataSource;
    }
    /**
     * 获取SqlSessionFactory
     * @param druidDataSource
     * @return
     */
    @Bean(name = "sqlSessionFactory")
    public SqlSessionFactory sqlSessionFactoryBean(DataSource druidDataSource) {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(druidDataSource);
        LogFactory.useLog4JLogging();
        //添加XML目录
        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        String xmlPath = environment.getProperty("mybatis.mapperLocations");
        try {
         bean.setMapperLocations(resolver.getResources(xmlPath));
            return bean.getObject();
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
    /**
     *
     * @param sqlSessionFactory
     * @return
     */
    @Bean
    public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
    /**
     * 增加事务
     * @param druidDataSource
     * @return
     */
    @Bean
    public DataSourceTransactionManager transactionManager(DataSource druidDataSource) {
        return new DataSourceTransactionManager(druidDataSource);
    }
}

8.2MabatisMapperScanConfig类

import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
 * Created by qqg on 2017/9/19.
 */
@Configuration
//注意，由于MabatisMapperScanConfig执行的比较早，所以必须有下面的注解
@AutoConfigureAfter(MybatisConfig.class)
public class MabatisMapperScanConfig {
    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer() {
        MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
        //注意这里的sqlSessionFactory就是MybatisConfig里面的sqlSessionFactoryBean方法，注解bean的名字
       mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
        //接口路径，通过这些接口调用sql的配置，操作数据库
      mapperScannerConfigurer.setBasePackage("com.mapper");
        return mapperScannerConfigurer;
    }
}

9. controller的编写

import com.hand.dto.Test;
import com.hand.service.ITestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
import java.util.logging.Logger;
/**
 * Created by qqg on 2017/9/15.
 */
@RestController
public class ComputeController {
    private final Logger logger = Logger.getLogger(String.valueOf(getClass()));
    @Autowired
    private DiscoveryClient client;
    @Autowired
    private ITestService service;
    @RequestMapping(value = "/list")
    public List getList(){
        return service.findAll();
    }
    @RequestMapping(value = "/add" ,method = RequestMethod.GET)
    public Integer add(@RequestParam Integer a, @RequestParam Integer b) {
        ServiceInstance instance = client.getLocalServiceInstance();

        Integer r = a + b;
        logger.info("/add, host:" + instance.getHost() + ", service_id:" + instance.getServiceId() + ", result:" + r);
        return r;
    }
}

10.建立数据库，以及表，这里的数据库名称为test,表名为test，里面的字段根据实体类的自己看。

11.重新启动3个服务，访问http://localhost:5555/api-a/list?accessToken=token

OK。

相关连接：http://blog.csdn.net/j903829182/article/details/75643661