spring boot 通过mybatis连接MySQL数据库

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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

<!-- 与数据库操作相关的依赖 -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-jdbc</artifactId>        </dependency>        <!--mybatis与springboot整合包-->        <dependency>            <groupId>org.mybatis.spring.boot</groupId>            <artifactId>mybatis-spring-boot-starter</artifactId>            <version>1.3.0</version>        </dependency>        <!--mysql驱动-->        <dependency>            <groupId>mysql</groupId>            <artifactId>mysql-connector-java</artifactId>        </dependency>        <!-- 使用druid数据源 -->        <dependency>            <groupId>com.alibaba</groupId>            <artifactId>druid</artifactId>            <version>1.1.1</version>        </dependency>        <!-- mybatis包 -->        <dependency>            <groupId>org.mybatis</groupId>            <artifactId>mybatis</artifactId>            <version>3.4.4</version>        </dependency>        <dependency>            <groupId>org.mybatis</groupId>            <artifactId>mybatis-spring</artifactId>            <version>1.3.1</version>        </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<Test> 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<Test> 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. */@Servicepublic class TestServiceImpl implements ITestService {    @Autowired    private TestMapper mapper;    @Override    public List<Test> 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：

<?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.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: 9092spring:  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: 20mybatis:  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. */@Configurationpublic 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. */@RestControllerpublic class ComputeController {    private final Logger logger = Logger.getLogger(String.valueOf(getClass()));    @Autowired    private DiscoveryClient client;    @Autowired    private ITestService service;    @RequestMapping(value = "/list")    public List<Test> 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;    }}