1、JDBC&DBCP总结

1、DBCP工具类的实现：

import javax.sql.DataSource;
import org.apache.commons.dbcp.BasicDataSource;

public class DBCPUtils {
    private static BasicDataSource ds;
    
    private static String dbName = "logandreg";
    private static String driverClassName = "com.mysql.jdbc.Driver";
    private static String url = "jdbc:mysql://localhost/" + dbName; //+一个具体的数据库名称
    private static String userName = "root";
    private static String password = "*****";
    
    static {
        ds = new BasicDataSource(); 
        ds.setDriverClassName(driverClassName);
        ds.setUrl(url);
        ds.setUsername(userName);
        ds.setPassword(password);
    }
    
    //注意返回到通用接口上
    public static DataSource getConnection() {
        return ds;
    }
}

2、核心操作：

//获取DButils的QueryRunner
QueryRunner qr = new QueryRunner(DBCPUtils.getConnection());
//一个接收数据库中一行数据的JavaBean,或者一个List<User> users
User user = null;
//sql语句
String sql = "select * from users where username = ? and psword = ?";
//执行查询所需要的参数
Object[] params = {username,psword};
/*
    Object BeanHandler<Object>(Object.class) 
    List<Object> BeanListHandler<>(Object.class) 
*/
try { //操作数据库
    user = qr.query(sql,new BeanHandler<User>(User.class), params);
} catch (SQLException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}