Spring Boot 揭秘与实战（二）数据存储篇

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。
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环境依赖

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


      
     
      org.springframework.boot
       
     
      spring-boot-starter-jdbc
     
    复制代码

添加mysql依赖。


      
     
      mysql
       
     
      mysql-connector-java
       
     
      5.1.35
     
    
      
     
      com.alibaba
       
     
      druid
       
     
      1.0.14
     
    复制代码

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.Driverspring.datasource.url=jdbc:mysql://localhost:3307/springboot_dbspring.datasource.username=rootspring.datasource.password=root复制代码

方案二手动创建

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

# mysqlsource.driverClassName = com.mysql.jdbc.Driversource.url = jdbc:mysql://localhost:3306/springboot_dbsource.username = rootsource.password = root复制代码

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;    }}复制代码

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;复制代码

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}复制代码

DAO相关

public interface AuthorDao {    int add(Author author);    int update(Author author);    int delete(Long id);    Author findAuthor(Long id);    List
    
      findAuthorList();}复制代码

我们来定义实现类，通过JdbcTemplate定义的数据访问操作。

@Repositorypublic 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
    
      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
      
        findAuthorList() {        List
       
         list = jdbcTemplate.query("select * from t_author", new Object[]{}, new BeanPropertyRowMapper
        
         (Author.class));        return list;    }}复制代码

Service相关

public interface AuthorService {    int add(Author author);    int update(Author author);    int delete(Long id);    Author findAuthor(Long id);    List
    
      findAuthorList();}复制代码

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
    
      findAuthorList() {        return this.authorDao.findAuthorList();    }}复制代码

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
    
      getAuthorList(HttpServletRequest request) {            List
     
       authorList = this.authorService.findAuthorList();    Map
      
        param = new HashMap
       
        ();    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");    }  }}复制代码

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：

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