mysql查询数据库

需要导入的jar包：

1、commons-dbutils-1.6.jar

2、mysql-connector-java-5.1.10.jar

获取链接封装：

package com.xingxue.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

import org.apache.commons.dbutils.DbUtils;

public class DBUtil {
    
    private final static String URL = "jdbc:mysql://localhost:3306/test";
    private final static String USER = "root";
    private final static String PASSWORD = "asdfghjkl";
    private static Connection conn =null;
    
    
    static{
        
        DbUtils.loadDriver("com.mysql.jdbc.Driver");
        try {
            conn = DriverManager.getConnection(URL, USER, PASSWORD);
        } catch (SQLException e) {
            e.printStackTrace();
            System.out.println("数据库连接失败！");
        }
        
    }
    
    
    public static Connection getConn() {
        return conn;
        }
    
    
}

数据库的查询语句

public class FeiyongDaoImpl implements FeiyongDao {
    
    QueryRunner queryRunner = new QueryRunner();
    @SuppressWarnings("rawtypes")
    public ArrayList selectFeiyong() {
        Connection conn = DBUtil.getConn();
        ArrayList list=null;
        try {
            String sql = "select * from db";
            list = (ArrayList) queryRunner.query(conn, sql,new BeanListHandler<Feiyong>(Feiyong.class));
            return list;
        } catch (SQLException e) {
            e.printStackTrace();
            System.out.println("数据库操作查询异常");
        }
        
        return list;
    }
}

package com.xingxue.util;
import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;
import org.apache.commons.dbutils.DbUtils;
public class DBUtil {private final static String URL = "jdbc:mysql://localhost:3306/test";private final static String USER = "root";private final static String PASSWORD = "asdfghjkl";private static Connection conn =null;static{DbUtils.loadDriver("com.mysql.jdbc.Driver");try {conn = DriverManager.getConnection(URL, USER, PASSWORD);} catch (SQLException e) {e.printStackTrace();System.out.println("数据库连接失败！");}}public static Connection getConn() {return conn;}}