3、Spring Boot+Mybatis

依赖配置

结合前面的内容，这里我们要嵌入数据库的操作，这里以操作mysql为例整合Mybatis，首先需要在原来的基础上添加以下依赖

<!-- mybatis依赖 --><dependency>    <groupId>org.mybatis.spring.boot</groupId>    <artifactId>mybatis-spring-boot-starter</artifactId>    <version>1.1.1</version></dependency>

当然啦，只依赖mybatis是不够的还需要依赖jdbc驱动以及返回json数据的json库(格式化数据)

<!-- MySql驱动 --><dependency>    <groupId>org.apache.tomcat</groupId>    <artifactId>tomcat-jdbc</artifactId></dependency><dependency>    <groupId>mysql</groupId>    <artifactId>mysql-connector-java</artifactId>    <version>5.1.21</version></dependency><!--Json库的依赖 -->    <dependency>    <groupId>com.alibaba</groupId>    <artifactId>fastjson</artifactId>    <version>1.1.43</version></dependency>

应用配置

接着需要在application.properties中添加数据库配置

#JDBC配置spring.datasource.url=jdbc:mysql://127.0.0.1:3306/weibo?useUnicode=true&characterEncoding=gbk&zeroDateTimeBehavior=convertToNullspring.datasource.username=rootspring.datasource.password=rootspring.datasource.driver-class-name=com.mysql.jdbc.Driver

这里连接的数据库名叫weibo，其中表结构如下：

---

接下来就需要来具体的初始化MyBatis配置以及数据表的操作了，先看一下工程结构

编写配置类

数据库相关的DataSource，SqlSeesion配置，其中DataSourse的配置可以理解为解读application.properties中的jdbc相关配置然后初始化JDBC驱动的，SqlSeesion配置主要是针对Mybatis使用事务操作时的配置信息。

package com.example.demo.config;import javax.sql.DataSource;import org.apache.ibatis.session.SqlSessionFactory;import org.mybatis.spring.SqlSessionFactoryBean;import org.mybatis.spring.annotation.MapperScan;import org.springframework.boot.autoconfigure.EnableAutoConfiguration;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.core.io.support.PathMatchingResourcePatternResolver;import org.springframework.jdbc.datasource.DataSourceTransactionManager;import org.springframework.transaction.PlatformTransactionManager;@EnableAutoConfiguration@ComponentScan@MapperScan("com.example.demo.mapper")public class JdbcConfig {    // DataSource配置    @Bean    @ConfigurationProperties(prefix = "spring.datasource")    public DataSource dataSource() {        return new org.apache.tomcat.jdbc.pool.DataSource();    }    // 提供SqlSeesion(数据库事务操作相关的配置)    @Bean    public SqlSessionFactory sqlSessionFactoryBean() throws Exception {        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();        sqlSessionFactoryBean.setDataSource(dataSource());        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();        sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath:/mybatis/*.xml"));        return sqlSessionFactoryBean.getObject();    }    @Bean    public PlatformTransactionManager transactionManager() {        return new DataSourceTransactionManager(dataSource());    }}

pom.xml配置中要添加配置解析组件

<dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-configuration-processor</artifactId>    <optional>true</optional></dependency>

添加Pojo类

该类主要接收数据表中的数据，所以属性基本上跟数据表的属性一致

package com.example.demo.bean;public class Diary {    private int id;    private String title;    private String content;    private String pubTime;    private int userId;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getTitle() {        return title;    }    public void setTitle(String title) {        this.title = title;    }    public String getContent() {        return content;    }    public void setContent(String content) {        this.content = content;    }    public String getPubTime() {        return pubTime;    }    public void setPubTime(String pubTime) {        this.pubTime = pubTime;    }    public int getUserId() {        return userId;    }    public void setUserId(int userId) {        this.userId = userId;    }    @Override    public String toString() {        return "Diary [id=" + id + ", title=" + title + ", content=" + content + ", pubTime=" + pubTime + ", userId="                + userId + "]";    }}

添加数据表操作接口

该类描述了操作数据表的过程，SprintBoot在运行中会根据类上的@Mapper注解找到它，因此不能落下这个注解

package com.example.demo.mapper;import org.apache.ibatis.annotations.Mapper;import org.apache.ibatis.annotations.Param;import org.apache.ibatis.annotations.Select;import com.example.demo.bean.Diary;@Mapperpublic interface DiaryMapper {    @Select("select * from diary where _id = #{id}")    public Diary getDiaryById(@Param("id")Integer id);}

使用

package com.example.demo.controller;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import com.alibaba.fastjson.JSON;import com.example.demo.bean.Diary;import com.example.demo.mapper.DiaryMapper;@RestControllerpublic class DiaryMappingController {    @Autowired    DiaryMapper diaryMapper;    @RequestMapping("/diary")    public String getDiary(Integer id){        Diary d = diaryMapper.getDiaryById(id);        String json = JSON.toJSONString(d);        return json;    }}

最后运行SpringBoot项目，然后在浏览器上输入网址：
http://localhost:8080/diary?id=2
这样即可看到结果

到此SpringBoot+Mybatis的整合就完成了

源码：https://github.com/huajianzh/spring/tree/master/springdemo