创建数据库

可以使用下面的SQL

create table A(
`id` INT (255) not null,
primary key (`id`)
);

创建实体类

新建一个AEntity类用于映射表A的一行：

@Component
public class AEntity {private int id;public int getId() {return id;}public void setId(int id) {this.id = id;}}

接写来的App类将演示从数据库里查询数据。

查询一行

关键代码：template.queryForObject(String sql, RowMapper<T> rowMapper)。

@Component("app")
public class App 
{   @Resourceprivate JdbcTemplate jdbcTempalte;public static void main( String[] args ){ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");App app = (App) context.getBean("app");JdbcTemplate template = app.getJdbcTempalte();AEntity aEntity = (AEntity) template.queryForObject("select * from a where id = 1 ", new RowMapper<AEntity>(){@Overridepublic AEntity mapRow(ResultSet rs, int rowNum) throws SQLException {AEntity aEntity = new AEntity();aEntity.setId( rs.getInt("id") );return aEntity;}} );System.out.println(aEntity.getId());}public JdbcTemplate getJdbcTempalte() {return jdbcTempalte;}public void setJdbcTempalte(JdbcTemplate jdbcTempalte) {this.jdbcTempalte = jdbcTempalte;}}

查询集合

@Component("app")
public class App 
{   @Resourceprivate JdbcTemplate jdbcTempalte;public static void main( String[] args ){ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");App app = (App) context.getBean("app");JdbcTemplate template = app.getJdbcTempalte();List<Long> list = template.queryForList("select * from a limit 0,15 ",Long.class);for(Long id : list){System.out.println(id);}}public JdbcTemplate getJdbcTempalte() {return jdbcTempalte;}public void setJdbcTempalte(JdbcTemplate jdbcTempalte) {this.jdbcTempalte = jdbcTempalte;}}