Spring Boot 揭秘与实战（二） 数据存储篇

文章链接：http://blog.720ui.com/2016/springboot_02_data_jdbc/

本文讲解 Spring Boot 基础下，如何使用 JDBC，配置数据源和通过 JdbcTemplate 编写数据访问。

环境依赖

修改 POM 文件，添加spring-boot-starter-jdbc依赖。

 <dependency>      <groupId>org.springframework.boot</groupId>      <artifactId>spring-boot-starter-jdbc</artifactId>  </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

使用 Spring Boot 默认配置，不需要在创建 dataSource 和 jdbcTemplate 的 Bean。

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    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    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;        }    }

SQL语句初始化

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;

使用JdbcTemplate操作

实体对象

    public class Author {        private Long id;        private String realName;        private String nickName;        // SET和GET方法    }

DAO相关

public interface AuthorDao {        int add(Author author);        int update(Author author);        int delete(Long id);        Author findAuthor(Long id);        List<Author> findAuthorList();    }

我们来定义实现类，通过JdbcTemplate定义的数据访问操作。

 @Repository    public class AuthorDaoImpl implements AuthorDao {        @Autowired        private JdbcTemplate jdbcTemplate;        @Override        public int add(Author author) {            return jdbcTemplate.update("insert into t_author(real_name, nick_name) values(?, ?)",                     author.getRealName(), author.getNickName());        }        @Override        public int update(Author author) {            return jdbcTemplate.update("update t_author set real_name = ?, nick_name = ? where id = ?",                     new Object[]{author.getRealName(), author.getNickName(), author.getId()});              }        @Override        public int delete(Long id) {            return jdbcTemplate.update("delete from t_author where id = ?", id);        }        @Override        public Author findAuthor(Long id) {            List<Author> list = jdbcTemplate.query("select * from t_author where id = ?", new Object[]{id}, new BeanPropertyRowMapper(Author.class));            if(null != list && list.size()>0){                Author auhtor = list.get(0);                return auhtor;            }else{                return null;            }        }        @Override        public List<Author> findAuthorList() {            List<Author> list = jdbcTemplate.query("select * from t_author", new Object[]{}, new BeanPropertyRowMapper<Author>(Author.class));            return list;        }    }

Service相关

public interface AuthorService {        int add(Author author);        int update(Author author);        int delete(Long id);        Author findAuthor(Long id);        List<Author> findAuthorList();    }

我们来定义实现类，Service层调用Dao层的方法，这个是典型的套路。

 @Service("authorService")    public class AuthorServiceImpl implements AuthorService {        @Autowired        private AuthorDao authorDao;        @Override        public int add(Author author) {            return this.authorDao.add(author);        }        @Override        public int update(Author author) {            return this.authorDao.update(author);              }        @Override        public int delete(Long id) {            return this.authorDao.delete(id);        }        @Override        public Author findAuthor(Long id) {            return this.authorDao.findAuthor(id);        }        @Override        public List<Author> findAuthorList() {            return this.authorDao.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    @RequestMapping(value="/data/jdbc/author")    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");        Author author = new Author();        if (author!=null) {            author.setId(Long.valueOf(userId));        }        author.setRealName(realName);        author.setNickName(nickName);        try{            this.authorService.add(author);        }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");        author.setRealName(realName);        author.setNickName(nickName);        try{            this.authorService.update(author);        }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");        }      }    }

总结

通过，上面这个简单的案例，我们发现 Spring Boot 仍然秉承了 Spring 框架的一贯套路，并简化 Spring 应用的初始搭建以及开发过程。

源代码

相关示例完整代码： [springboot-action](https://github.com/lianggzone/springboot-action)

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