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;
- }
- }
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;
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。
来源:https://www.cnblogs.com/wirr/p/8989035.html