JdbcTemplate

JdbcTemplate

Spring框架对JDBC进行了封装，使用JdbcTemplate实现对数据库的操作

1-连接数据库

<beans>
	<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
          destroy-method="close">
        <property name="url" value="jdbc:mysql:///book?useUnicode=true&amp;characterEncoding=utf8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    </bean>

    <!--    jdbcTemplate对象配置 并注入-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<!--        注入对象-->
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <context:component-scan base-package="JdbcTemplate"></context:component-scan>
</beans>

2-注解进行注入

@Repository
public class BookDaoImpl implements BookDAO {
    @Autowired
    private JdbcTemplate jdbcTemplate;
    ...
    ...
}

@Service
public class BookService {
    @Autowired
    private BookDAO bookDAO;
}

3-编写DAO层实现

package JdbcTemplate.dao;

import JdbcTemplate.pojo.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import java.util.Arrays;
import java.util.List;


@Repository
public class BookDaoImpl implements BookDAO {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Override
    public void add(Book book) {
        String sql = "insert into t_user values(?,?,?,?)";
        int update = jdbcTemplate.update(sql, book.getId(), book.getUsername(), book.getPassword(), book.getEmail());
        System.out.println("添加了：" + update + " 行！");
    }

    @Override
    public void update(Book book) {
        String sql = "update t_user set username=?,password=?,email=? where id=?";
        int update = jdbcTemplate.update(sql, book.getUsername(),book.getPassword(),book.getEmail(),book.getId());
        System.out.println("修改了：" + update + " 行！");
    }

    @Override
    public void delete(String id) {
        String sql = "delete from t_user where id=?";
        int update = jdbcTemplate.update(sql, id);
        System.out.println("删除了：" + update + " 行！");
    }

    @Override
    public int selectCount() {
        String sql = "select count(*) from t_user";
        Integer integer = jdbcTemplate.queryForObject(sql, Integer.class);
        return integer;
    }

    /**
     * 查询某个信息
     * @param id 查询索引
     * @return
     */
    @Override
    public Book findBookInfo(int id) {
        String sql = "select * from t_user where id=?";
        Book book = jdbcTemplate.queryForObject(sql, new BeanPropertyRowMapper<>(Book.class), id);
        return book;
    }

    @Override
    public List<Book> findBookList() {
        String sql = "select * from t_user";
        List<Book> list = jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(Book.class));
        return list;
    }

    @Override
    public void addBatch(List<Object[]> batch) {
        String sql = "insert into t_user values(?,?,?,?)";
        int[] ints = jdbcTemplate.batchUpdate(sql, batch);
        System.out.println(Arrays.toString(ints));
    }

    @Override
    public void batchDelete(List<Object[]> batch) {
        String sql = "delete from t_user where id=?";
        int[] ints = jdbcTemplate.batchUpdate(sql, batch);
        System.out.println(Arrays.toString(ints));
    }
}

• queryForObject（sql,xxx.class） 查询返回某个值
• queryForObject（sql,new BeanPropertyRowMapper<>(Book.class),xxx） 查询返回某个对象
• update(sql,xxx)：更新、删除、修改某个对象
• query(sql,RowMapper<>(Book.class))：返回集合
• batchUpdate(sql,List)：批量修改、删除、添加