Springboot 整合JDBC

对于数据访问层，无论是 SQL(关系型数据库) 还是 NOSQL(非关系型数据库)，Spring Boot 底层都是采用 Spring Data 的方式进行统一处理。

Spring Boot 底层都是采用 Spring Data 的方式进行统一处理各种数据库

Sping Data 官网：https://spring.io/projects/spring-data

1 SpringBoot 整合JDBC

1 导入依赖

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

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

2 springboot 配置文件 配置数据库连接信息

spring:
  datasource:
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai

3 测试数据库是否连接上

• 分析SpringBoot 数据源自动装配

// 使@ConfigurationProperties 注解的类生效。
@EnableConfigurationProperties(DataSourceProperties.class)
@Import({ DataSourcePoolMetadataProvidersConfiguration.class, DataSourceInitializationConfiguration.class })
public class DataSourceAutoConfiguration {

}

我们能够修改的属性在DataSourceProperties中

@ConfigurationProperties(prefix = "spring.datasource")
public class DataSourceProperties implements BeanClassLoaderAware, InitializingBean {

}

4 测试数据源

@SpringBootTest
class SpringbootJdbcApplicationTests {

    @Autowired
    DataSource dataSource;

    @Test
    void contextLoads() {
        System.out.println(dataSource);
    }

}

结果
class com.zaxxer.hikari.HikariDataSource

HikariProxyConnection@839259983 wrapping com.mysql.cj.jdbc.ConnectionImpl@42fb8c87

2 SpringBoot JDBC 增删改查

SpringBoot 自动装配JdbcTemplate 帮助我们进行数据库操作

1 搜索JdbcTemplateAutoConfiguration

@AutoConfigureAfter(DataSourceAutoConfiguration.class)
@EnableConfigurationProperties(JdbcProperties.class)
@Import({ JdbcTemplateConfiguration.class, NamedParameterJdbcTemplateConfiguration.class })
public class JdbcTemplateAutoConfiguration {

}

2 进入JdbcTemplateConfiguration.class

@Configuration(proxyBeanMethods = false)
@ConditionalOnMissingBean(JdbcOperations.class)
class JdbcTemplateConfiguration {

	@Bean
	@Primary
	JdbcTemplate jdbcTemplate(DataSource dataSource, JdbcProperties properties) {
		JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);
		JdbcProperties.Template template = properties.getTemplate();
		jdbcTemplate.setFetchSize(template.getFetchSize());
		jdbcTemplate.setMaxRows(template.getMaxRows());
		if (template.getQueryTimeout() != null) {
			jdbcTemplate.setQueryTimeout((int) template.getQueryTimeout().getSeconds());
		}
		return jdbcTemplate;
	}

}

1 使用JDBCtemplate 进行增删改查

@RestController
public class JdbcController {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @RequestMapping("/user")
    public List<Map<String,Object>> userList(){
        String sql  = "select * from user";
        List<Map<String, Object>> maps = jdbcTemplate.queryForList(sql);
        return maps;
    }


    @RequestMapping("/addUser")
    public String addUser(){
        String sql = "insert into user(id,name,pwd) values (?,?,?)";
        Object[] objects = new Object[3];
        objects[0] = 4;
        objects[1]="zz";
        objects[2]="1234";
        jdbcTemplate.update(sql,objects);
        return  "jdbcTmeplate-Add";
    }

    @RequestMapping("/updateUser/{id}")
    public String update(@PathVariable("id") int id){
        String sql = "update user set name=?, pwd=? where id ="+id;
        Object[] objects = new Object[2];
        objects[0]="updatezz";
        objects[1]="1234";
        jdbcTemplate.update(sql,objects);
        return  "jdbcTmeplate-update";
    }

    @RequestMapping("/deleteUser/{id}")
    public String deleteUser(@PathVariable("id") int id){
        String sql = "delete  from user where id ="+id;
        jdbcTemplate.update(sql);
        return  "jdbcTmeplate-delete";
    }
}