(德鲁伊)druid数据库连接池工具类和QueryRunner(增删改查)的结合使用

druid数据库连接池工具类

依赖的jar包 druid-1.1.9.jar

package com.zhanghan.utils;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import sun.applet.Main;

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


public class JDBCUtils {

    public static void main(String[] args) {

    }
//    声明数据库连接池
    private static DruidDataSource dataSource;

//    静态代码块初始化
    static {
    Properties prop = new Properties();
//    读取JDBC.properties配置文件

    try {
        InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("jdbc.properties");
        prop.load(is);
//        创建数据库连接池
       dataSource = (DruidDataSource) DruidDataSourceFactory.createDataSource(prop);
        System.out.println(dataSource.getConnection());
    } catch (Exception e) {
        e.printStackTrace();
    }
}


public static Connection getConnection(){
    Connection connection = null;

    try {
        connection = dataSource.getConnection();
    }catch (SQLException e){
        e.printStackTrace();
    }


    return  connection;
}

    
    public static  void close(Connection connection){
        if(connection!=null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

3.baseDao

再javaWeb开发的过程中，可以创建一个抽象类baseDao来简便Dao层的开发，代码如下使用QueryRunner

依赖的jar包

package com.zhanghan.dao.impl;

import com.zhanghan.utils.JDBCUtils;
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.ScalarHandler;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;


public abstract  class  baseDao {

    //使用dautils操作数据库
    private QueryRunner queryRunner = new QueryRunner();

    
    public int update(String sql,Object ... args){

        Connection connection = JDBCUtils.getConnection();
        try {
            int update = queryRunner.update(connection, sql, args);
        return  update;
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            JDBCUtils.close(connection);
        }

        return  -1;
    }

    
    public  T queryForOne(String sql,Class type,Object ... args){
        Connection connection = JDBCUtils.getConnection();

        try {
            return  queryRunner.query(connection,sql,new BeanHandler(type),args);
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            JDBCUtils.close(connection);
        }

        return null;
    }

    
    public  List queryForList(String sql,Class type,Object ... args){
        Connection connection = JDBCUtils.getConnection();
        try {
            return  queryRunner.query(connection,sql,new BeanListHandler(type),args);
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            JDBCUtils.close(connection);
        }
        return null;
    }

    
    public Object queryForSinglevalue(String sql,Object ... args){

        Connection connection = JDBCUtils.getConnection();

        try {
          return  queryRunner.query(connection,sql,new ScalarHandler(),args);
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            JDBCUtils.close(connection);
        }
        return  null;
    }
}