spring3 jdbctemplate 注解实例

标签： javawebTimestampspring第一步,先引入需要的包,这里不作详细说明

 

第二步,配置注解扫描,txManager是事务管理提供datasource就可以了

 

<aop:aspectj-autoproxy />

    <!-- transaction manager, use JtaTransactionManager for global tx -->
    <bean id="txManager"
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dynamicDataSource" />
    </bean>

    <!--
        enable component scanning (beware that this does not enable mapper
        scanning!)
    -->
    <context:component-scan base-package="com.shadow" />

    <!-- enable autowire -->
    <context:annotation-config />

    <!-- enable transaction demarcation with annotations -->
    <tx:annotation-driven transaction-manager="txManager" />

第三步,配置jdbctemplate的实例,同样提供一个datasource就可以了

 

 

<!-- JDBC模板 -->
    <bean id="jdbcTemplate"
        class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dynamicDataSource" />
    </bean>

第四步,写个BaseDao方便下面的dao层调用,由于时间转换经常用到,这里只写了个通用的时间转换

 

 

/**
 *
 * @author shadow
 * @email [email protected]
 * @create 2012.04.28
 *
 * @param <T>
 */
public abstract class AbstractBaseDao<T> implements DateFormatEntry {

    // SPRING JDBC模板接口
    private JdbcTemplate jdbcTemplate;

    public JdbcTemplate getJdbcTemplate() {
        return jdbcTemplate;
    }

    @Resource
    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    /**
     * 获取日期
     *
     * @param timestamp
     * @return Date
     */
    public Date getDate(Timestamp timestamp) {
        return toDate(timestamp, null);
    }

    /**
     * 获取日期
     *
     * @param timestamp
     * @param format
     * @return Date
     */
    public Date getDate(Timestamp timestamp, String format) {
        return toDate(timestamp, format);
    }

    /**
     * Timestamp按格式转换成Date
     *
     * @param timestamp
     * @param format
     * @return Date
     */
    public Date toDate(Timestamp timestamp, String format) {
        Date date = null;
        if (null == format || "".equals(format))
            format = DEFAULT_FORMAT;
        SimpleDateFormat sdf = new SimpleDateFormat(format);
        try {
            date = sdf.parse(sdf.format(timestamp));
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;
    }

}

第五步,写个UserDao接口跟实现类

 

 

public interface UserDao {

    public List<User> queryByUserName(String username);

    public int checkUser(String username);

    public List<User> queryForAll();

}

 

这里使用@Component("userDao"),相当于在xml配置里做一个<bean id="userDao" class="xxxxxx.UserDaoImpl"/>,然后我们在service调用就直接Resource("userDao")就能自动匹配这个实现类了

@Component("userDao")
public class UserDaoImpl extends AbstractBaseDao<User> implements UserDao {

    public int checkUser(String username) {
        // TODO Auto-generated method stub
        return 0;
    }

    @SuppressWarnings("unchecked")
    public List<User> queryByUserName(String username) {
        String sql = "select t1.* from t_user t1 where t1.username = ?";
        List<User> list = this.getJdbcTemplate().query(sql,
                new Object[] { username }, new UserMapper());
        return list;
    }

    public List<User> queryForAll() {
        SqlRowSet rowSet = getJdbcTemplate().queryForRowSet(null);
        while (rowSet.next()) {
        }
        return null;
    }

    @SuppressWarnings("unchecked")
    private class UserMapper implements RowMapper {
        public Object mapRow(ResultSet rs, int i) throws SQLException {
            User vo = new User();
            vo.setId(rs.getInt("id"));
            vo.setUsername(rs.getString("username"));
            vo.setPassword(rs.getString("password"));
            vo.setName(rs.getString("name"));
            return vo;
        }
    }

}

第六步,写service层调用dao的方法

 

 

public interface UserService {

    /**
     * 更新登录信息
     *
     * @param user
     */
    public void LoginForUpdate(User user);

    /**
     * 安全退出功能
     *
     * @return String
     */
    public String logout();

    /**
     * 检测用户是否存在
     *
     * @param username
     * @return Boolean
     */
    public boolean checkUser(String username);

    /**
     * 通过用户名获取账号
     *
     * @param username
     * @return List<User>
     */
    public List<User> findByUserName(String username);

 

这里使用了的@Resource没有带参数就是默认使用接口类名首字母小写(例如接口是UserDao,默认匹配是userDao),@Transactional是事务的注解,可加各种参数设置,

具体请看帮助文档

@Transactional
@Component("userService")
public class UserServiceImpl implements UserService {

    @Resource
    private UserDao userDao;

    public void LoginForUpdate(User user) {
        // TODO Auto-generated method stub
    }

    public boolean checkUser(String username) {
        // TODO Auto-generated method stub
        return false;
    }

    public List<User> findByUserName(String username) {
        return this.userDao.queryByUserName(username);
    }

    public String logout() {
        // TODO Auto-generated method stub
        return null;
    }

}

第七步,写junit测试

 

 

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:application.xml")
public class Junit {

    @Resource
    private UserService userService;

    @Test
    public void test() {
        for (int i = 0; i < 10; i++) {
            List<User> users = userService.findByUserName("3213231");
            System.out.println("当前用户数:" + users.size());
        }
    }

}

最后右键run as junit就ok了

 

 

附言,其实spring jdbctemplate是很灵活的,性能也很不错,你能使用queryForXX一类的方法返回map,也能返回原始ResultSet,当然也能使用回调接口映射成对象,我的例子里就是演示了如何把结果集映射成实体对象