commons-dbutils工具栏的编写

db.properties

driverClass=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/test_db?useUnicode=true&characterEncoding=UTF-8&jdbcCompliantTruncation=false
user=root
password=

　　

commonsDbutils工具类

package com.variflight.b.gateway.utils;

import com.variflight.b.gateway.entity.po.VisitorRateConfPO;
import org.apache.commons.dbutils.BasicRowProcessor;
import org.apache.commons.dbutils.GenerousBeanProcessor;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.BeanMapHandler;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import java.util.Properties;

/**
 * @author muyang
 * @date 2019/5/23 11:37
 */
public class CommonsDbutils {

    private static Connection conn;

    private static String driverClass;

    private static String url;

    private static String user;

    private static String password;

    static {

        try {
            readDBConfig();
            Class.forName(driverClass);
            conn = DriverManager.getConnection(url, user, password);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void readDBConfig(){
        try {
            InputStream in = CommonsDbutils.class.getClassLoader().getResourceAsStream("db.properties");
            Properties pro = new Properties();
            pro.load(in);
            driverClass = pro.getProperty("driverClass");
            url = pro.getProperty("url");
            user = pro.getProperty("user");
            password = pro.getProperty("password");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static Connection getConnection(){
        return conn;
    }


    public static <T> T queryBean(Class<T> clazz, String sql){
        T t  = null;
        QueryRunner queryRunner = new QueryRunner();
        try {
            t = queryRunner.query(conn, sql, new BeanHandler<>(clazz, new BasicRowProcessor(
                    new GenerousBeanProcessor()
            )));
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return t;
    }

    public static <T> List<T> queryBeanList(Class<T> clazz, String sql){
        List<T> t  = null;
        QueryRunner queryRunner = new QueryRunner();
        try {
            t = queryRunner.query(conn, sql, new BeanListHandler<>(clazz, new BasicRowProcessor(
                    new GenerousBeanProcessor()
            )));
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return t;
    }

    public static <T> Map<String, T> queryMap(Class<T> clazz,  String sql){
        Map<String,  T> t =null;
        QueryRunner runner = new QueryRunner();
        try {
            t = runner.query(conn, sql, new BeanMapHandler<String, T>(clazz));
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return t;
    }



}

　　

测试

  public static void main(String[] args){

        //获取连接
        String sql = "select * from visitor_rate_conf";
        //List<VisitorRateConfPO> confPOList = queryBeanList(conn, sql);
        //VisitorRateConfPO confPOList = CommonsDbutils.queryBean(VisitorRateConfPO.class, sql);
        List<VisitorRateConfPO> confPOList = CommonsDbutils.queryBeanList(VisitorRateConfPO.class,  sql);
        //Map<String, VisitorRateConfPO> confPOList = CommonsDbutils.queryMap(VisitorRateConfPO.class,sql);
        System.out.println(confPOList);
    }