Spring Boot 揭秘与实战（二）数据存储篇

文章目录

本文讲解Spring Boot基础下，如何整合MyBatis框架，编写数据访问。

环境依赖

修改 POM 文件，添加mybatis-spring-boot-starter依赖。值得注意的是，可以不添加spring-boot-starter-jdbc。因为，mybatis-spring-boot-starter依赖中存在spring-boot-starter-jdbc。

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

添加mysql依赖。

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.35</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.14</version>
</dependency>

数据源

方案一使用 Spring Boot 默认配置

在 src/main/resources/application.properties 中配置数据源信息。

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3307/springboot_db?useUnicode = true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull
spring.datasource.username=root
spring.datasource.password=root

方案二手动创建

在 src/main/resources/config/source.properties 中配置数据源信息。

# mysql
source.driverClassName = com.mysql.jdbc.Driver
source.url = jdbc:mysql://localhost:3306/springboot_db?useUnicode = true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull
source.username = root
source.password = root

通过 Java Config 创建 dataSource 和jdbcTemplate 。

@Configuration
@EnableTransactionManagement
@PropertySource(value = {"classpath:config/source.properties"})
public class BeanConfig {
@Autowired
private Environment env;
@Bean(destroyMethod = "close")
public DataSource dataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName(env.getProperty("source.driverClassName").trim());
dataSource.setUrl(env.getProperty("source.url").trim());
dataSource.setUsername(env.getProperty("source.username").trim());
dataSource.setPassword(env.getProperty("source.password").trim());
return dataSource;
}
@Bean
public JdbcTemplate jdbcTemplate() {
JdbcTemplate jdbcTemplate = new JdbcTemplate();
jdbcTemplate.setDataSource(dataSource());
return jdbcTemplate;
}
}

脚本初始化

先初始化需要用到的SQL脚本。

CREATE DATABASE /*!32312 IF NOT EXISTS*/`springboot_db` /*!40100 DEFAULT CHARACTER SET utf8 */;
USE `springboot_db`;
DROP TABLE IF EXISTS `t_author`;
CREATE TABLE `t_author` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT COMMENT '用户ID',
`real_name` varchar(32) NOT NULL COMMENT '用户名称',
`nick_name` varchar(32) NOT NULL COMMENT '用户匿名',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

MyBatis整合

方案一通过注解的方式

实体对象

public class Author {
private Long id;
@JSONField(name="real_name")
private String realName;
@JSONField(name="nick_name")
private String nickName;
// SET和GET方法
}

DAO相关

@Mapper
public interface AuthorMapper {
@Insert("insert into t_author(real_name, nick_name) values(#{real_name}, #{nick_name})")
int add(@Param("realName") String realName, @Param("nickName") String nickName);
@Update("update t_author set real_name = #{real_name}, nick_name = #{nick_name} where id = #{id}")
int update(@Param("real_name") String realName, @Param("nick_name") String nickName, @Param("id") Long id);
@Delete("delete from t_author where id = #{id}")
int delete(Long id);
@Select("select id, real_name as realName, nick_name as nickName from t_author where id = #{id}")
Author findAuthor(@Param("id") Long id);
@Select("select id, real_name as realName, nick_name as nickName from t_author")
List<Author> findAuthorList();
}

Service相关

@Service
public class AuthorService {
@Autowired
private AuthorMapper authorMapper;
public int add(String realName, String nickName) {
return this.authorMapper.add(realName, nickName);
}
public int update(String realName, String nickName, Long id) {
return this.authorMapper.update(realName, nickName, id);
}
public int delete(Long id) {
return this.authorMapper.delete(id);
}
public Author findAuthor(Long id) {
return this.authorMapper.findAuthor(id);
}
public List<Author> findAuthorList() {
return this.authorMapper.findAuthorList();
}
}

Controller相关

为了展现效果，我们先定义一组简单的　RESTful API 接口进行测试。

@RestController("mybatis.authorController")
@RequestMapping(value="/data/mybatis/author")
@MapperScan("com.lianggzone.springboot.action.data.mybatis.dao")
public class AuthorController {
@Autowired
private AuthorService authorService;
/**
* 查询用户列表
*/
@RequestMapping(method = RequestMethod.GET)
public Map<String,Object> getAuthorList(HttpServletRequest request) {
List<Author> authorList = this.authorService.findAuthorList();
Map<String,Object> param = new HashMap<String,Object>();
param.put("total", authorList.size());
param.put("rows", authorList);
return param;
}
/**
* 查询用户信息
*/
@RequestMapping(value = "/{userId:\\d+}", method = RequestMethod.GET)
public Author getAuthor(@PathVariable Long userId, HttpServletRequest request) {
Author author = this.authorService.findAuthor(userId);
if(author == null){
throw new RuntimeException("查询错误");
}
return author;
}
/**
* 新增方法
*/
@RequestMapping(method = RequestMethod.POST)
public void add(@RequestBody JSONObject jsonObject) {
String userId = jsonObject.getString("user_id");
String realName = jsonObject.getString("real_name");
String nickName = jsonObject.getString("nick_name");
try{
this.authorService.add(realName, nickName);
}catch(Exception e){
e.printStackTrace();
throw new RuntimeException("新增错误");
}
}
/**
* 更新方法
*/
@RequestMapping(value = "/{userId:\\d+}", method = RequestMethod.PUT)
public void update(@PathVariable Long userId, @RequestBody JSONObject jsonObject) {
Author author = this.authorService.findAuthor(userId);
String realName = jsonObject.getString("real_name");
String nickName = jsonObject.getString("nick_name");
try{
this.authorService.update(realName, nickName, author.getId());
}catch(Exception e){
e.printStackTrace();
throw new RuntimeException("更新错误");
}
}
/**
* 删除方法
*/
@RequestMapping(value = "/{userId:\\d+}", method = RequestMethod.DELETE)
public void delete(@PathVariable Long userId) {
try{
this.authorService.delete(userId);
}catch(Exception e){
throw new RuntimeException("删除错误");
}
}
}

方案二通过配置文件的方式

实体对象

public class Author {
private Long id;
@JSONField(name="real_name")
private String realName;
@JSONField(name="nick_name")
private String nickName;
// SET和GET方法
}

配置相关

在 src/main/resources/mybatis/AuthorMapper.xml 中配置数据源信息。

<?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.lianggzone.springboot.action.data.mybatis.dao.AuthorMapper2">
<resultMap id="authorMap" type="Author">
<id property="id" column="id" />
<result property="realName" column="real_name" />
<result property="nickName" column="nick_name" />
</resultMap>
<select id="findAuthor" resultMap="authorMap" resultType="Author">
select id, real_name, nick_name from t_author where id = #{id}
</select>
</mapper>

在 src/main/resources/application.properties 中配置数据源信息。

mybatis.mapper-locations=classpath*:mybatis/*Mapper.xml
mybatis.type-aliases-package=com.lianggzone.springboot.action.data.mybatis.entity

DAO相关

public interface AuthorMapper2 {
Author findAuthor(@Param("id") Long id);
}

Service相关

@Service
public class AuthorService2 {
@Autowired
private AuthorMapper2 authorMapper;
public Author findAuthor(Long id) {
return this.authorMapper.findAuthor(id);
}
}

Controller相关

为了展现效果，我们先定义一组简单的　RESTful API 接口进行测试。

@RestController("mybatis.authorController2")
@RequestMapping(value="/data/mybatis/author2")
@MapperScan("com.lianggzone.springboot.action.data.mybatis.dao")
public class AuthorController2 {
@Autowired
private AuthorService2 authorService;
/**
* 查询用户信息
*/
@RequestMapping(value = "/{userId:\\d+}", method = RequestMethod.GET)
public Author getAuthor(@PathVariable Long userId, HttpServletRequest request) {
Author author = this.authorService.findAuthor(userId);
if(author == null){
throw new RuntimeException("查询错误");
}
return author;
}
}

总结

上面这个简单的案例，让我们看到了 Spring Boot 整合 MyBatis 框架的大概流程。那么，复杂的场景，大家可以参考使用一些比较成熟的插件，例如com.github.pagehelper、mybatis-generator-maven-plugin等。

源代码

相关示例完整代码： springboot-action

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版权声明：本文由 梁桂钊 发表于梁桂钊的博客
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文章标题：Spring Boot 揭秘与实战（二）数据存储篇 - 数据访问与多数据源配置
文章链接：http://blog.720ui.com/2016/springboot_02_data_datasource/