（数据库课设）数据库连接池&amp；&amp；Dbutils实现数据库操作（解放双手，无需在自写增删改查）

本文链接：https://blog.youkuaiyun.com/2401_84978573/article/details/138986589

既有适合小白学习的零基础资料，也有适合3年以上经验的小伙伴深入学习提升的进阶课程，涵盖了95%以上C C++开发知识点，真正体系化！

由于文件比较多，这里只是将部分目录截图出来，全套包含大厂面经、学习笔记、源码讲义、实战项目、大纲路线、讲解视频，并且后续会持续更新

        //采用类加载方式获取文件的内容，并封装成流
        InputStream is = ClassLoader.getSystemClassLoader().getResourceAsStream("Druid.properties");
        //将流传入到pros对象中
        pros.load(is);
        //利用工厂类创建数据库连接池
        source = DruidDataSourceFactory.createDataSource(pros);
    }catch (Exception e){
        e.printStackTrace();
    }
}
public static Connection getConnByDruid() throws Exception {
    //所有的数据连接池要想被java所使用，都必须先实现sun公司提供的一个接口DateSource
    //获取数据库连接池对象
    Connection conn = source.getConnection();
    return conn;
}

}



## 三.测试数据库连接池是否创建成功

/**

druid测试数据库连接池技术类
*/
public class TestDruid {
@Test
public void getDruidConn() throws Exception {
Properties pros = new Properties();
InputStream is = ClassLoader.getSystemClassLoader().getResourceAsStream(“Druid.properties”);
pros.load(is);
//所有的数据连接池要想被java所使用，都必须先实现sun公司提供的一个接口DateSource
//获取数据库连接池对象
DataSource source = DruidDataSourceFactory.createDataSource(pros);
Connection conn = source.getConnection();
System.out.println(conn);

}
}


![](https://img-blog.csdnimg.cn/c0a9a91f61fa475096b96b9e490fb492.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBA5L2Z5omv,size_20,color_FFFFFF,t_70,g_se,x_16)


## 


## 


![](https://img-blog.csdnimg.cn/23c0b5699f81421e9ec950c0516c3132.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBA5L2Z5omv,size_20,color_FFFFFF,t_70,g_se,x_16)


 


## 


##  四.利用Dbutils.jar，使用封装好的增删改查方法

public class Testdbutil {
//使用QueryRunner和数据库连接池实现数据库的增删改
@Test
public void testQueryRunnerUpdate() {
Connection conn = null;
try {
QueryRunner queryRunner = new QueryRunner();
conn = JDBCUtils.getConnByDruid();
String sql = “insert into user_tab (id,name,balance) values(?,?,?)”;
int count = queryRunner.update(conn, sql, 154, “吴用”, 10001);
}catch (Exception e){
e.printStackTrace();
}finally {
JDBCUtils.closeResource(conn,null);
}
}

//使用QueryRunner实现数据的单条查询
@Test
public void testQueryRunnerSelect() throws SQLException {
    Connection conn = null;
    try{
        conn = JDBCUtils.getConnByDruid();
        QueryRunner queryRunner = new QueryRunner();
        String sql = "select id,name,balance from user_tab where id = ?";
        BeanHandler beanHandler = new BeanHandler<User>(User.class);
        Object query = queryRunner.query(conn, sql, beanHandler, 109);
        System.out.println(query);
    }catch (Exception e){
        e.printStackTrace();
    }finally {
        JDBCUtils.closeResource(conn,null);
    }

}

//使用QueryRunner实现查询多条语句
@Test
public void testQueryRunnerSelectManyInfo() throws SQLException {
    Connection conn = null;
    try{
        conn = JDBCUtils.getConnByDruid();
        QueryRunner queryRunner = new QueryRunner();
        String sql = "select id,name,balance from user_tab where id > ?";
        BeanListHandler<User> listHandler = new BeanListHandler<>(User.class);
        List<User> query = queryRunner.query(conn, sql, listHandler, 106);
        query.forEach(System.out::println);
    }catch (Exception e){
        e.printStackTrace();
    }finally {
        JDBCUtils.closeResource(conn,null);
    }

}

//使用QueryRunner实现特殊查询
@Test
public void testQueryRunnerSelect3() {
    Connection conn = null;
    try{
        conn = JDBCUtils.getConnByDruid();
        QueryRunner queryRunner = new QueryRunner();
        String sql = "select count(*) from user_tab";
        ScalarHandler<Object> handler = new ScalarHandler<>();
        Long query =(Long) queryRunner.query(conn, sql, handler);
        System.out.println("user表中有"+query+"条数据");
    }catch (Exception e){
        e.printStackTrace();
    }finally {
        //悄悄的关闭资源
        DbUtils.closeQuietly(conn);
    }