spring boot自动配置与jdbc模板自动装配数据源问题

使用Spring Boot的自动配置功能和JdbcTemplate的自动装配功能，可以方便地配置和使用数据源。在本文中，我们将探讨如何使用这些功能来简化数据源的配置，并提供一个案例代码来演示其用法。

spring.datasource.url=jdbc:mysql://localhost:3306/mydb
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

java
@Service
public class UserService {
    
    private JdbcTemplate jdbcTemplate;
    
    @Autowired
    public UserService(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }
    
    public List getAllUsers() {
        String sql = "SELECT * FROM users";
        List users = jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(User.class));
        return users;
    }
}

xml
    
        org.springframework.boot
        spring-boot-starter
    
    
        org.springframework.boot
        spring-boot-starter-jdbc
    
    
        mysql
        mysql-connector-java
    

java
@Configuration
public class DataSourceConfig {
    @Value("${spring.datasource.url}")
    private String url;
    @Value("${spring.datasource.username}")
    private String username;
    @Value("${spring.datasource.password}")
    private String password;
    @Value("${spring.datasource.driver-class-name}")
    private String driverClassName;
    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        dataSource.setDriverClassName(driverClassName);
        return dataSource;
    }
}

java
@Service
public class UserService {
    private JdbcTemplate jdbcTemplate;
    @Autowired
    public UserService(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }
    public List getAllUsers() {
        String sql = "SELECT * FROM users";
        List users = jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(User.class));
        return users;
    }
}

java
@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}