|NO.Z.00095|——————————|BigDataEnd|——|Java&MySQL.数据库连接池和DBUtils.V04|——|MySQL.v04|DBCP连接池工具类编写|

一、DBCP连接池工具类编写

### --- 编写工具类

——>        连接数据库表的工具类, 采用DBCP连接池的方式来完成
——>        Java中提供了一个连接池的规则接口 ： DataSource , 它是java中提供的连接池
——>        在DBCP包中提供了DataSource接口的实现类，我们要用的具体的连接池 BasicDataSource 类

二、代码示例

public class DBCPUtils {
    //1.定义常量 保存数据库连接的相关信息
    public static final String DRIVERNAME = "com.mysql.jdbc.Driver";
    public static final String URL = "jdbc:mysql://localhost:3306/db5?characterEncoding=UTF-8";
    public static final String USERNAME = "root";
    public static final String PASSWORD = "123456";
    //2.创建连接池对象 (有DBCP提供的实现类)
    public static BasicDataSource dataSource = new BasicDataSource();
    //3.使用静态代码块进行配置
    static{
        dataSource.setDriverClassName(DRIVERNAME);
        dataSource.setUrl(URL);
        dataSource.setUsername(USERNAME);
        dataSource.setPassword(PASSWORD);
    }
    //4.获取连接的方法
    public static Connection getConnection() throws SQLException {

        //从连接池中获取连接
        Connection connection = dataSource.getConnection();
        return connection;
    }

    //5.释放资源方法
    public static void close(Connection con, Statement statement){
        if(con != null && statement != null){
            try {
                statement.close();
                //归还连接
            con.close();
         } catch (SQLException e) {
                e.printStackTrace();
            }
       }
    }
    public static void close(Connection con, Statement statement, ResultSet resultSet){
        if(con != null && statement != null && resultSet != null){
            try {
                resultSet.close();
                statement.close();
                //归还连接
                con.close();
            } catch (SQLException e) {
                 e.printStackTrace();
             }
        }
    }
}

三、sql语句

package com.yanqi.jdbc06;

import org.apache.commons.dbcp.BasicDataSource;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DbcpUtils {

    //1.定义常量 保存数据库连接的相关信息
    public static final String DRIVERNAME = "com.mysql.jdbc.Driver";
    public static final String URL = "jdbc:mysql://localhost:3306/db5?characterEncoding=UTF-8";
    public static final String USERNAME = "root";
    public static final String PASSWORD = "123456";

    //2.创建连接池对象 (有DBCP提供的实现类)
    public static BasicDataSource dataSource = new BasicDataSource();

    //3.使用静态代码块进行配置
    static{
        dataSource.setDriverClassName(DRIVERNAME);
        dataSource.setUrl(URL);
        dataSource.setUsername(USERNAME);
        dataSource.setPassword(PASSWORD);
        dataSource.setMaxActive(20);
    }

    //4.获取连接的方法
    public static Connection getConnection() throws SQLException {

        //从连接池中获取连接
        Connection connection = dataSource.getConnection();
        return connection;
    }

    //5.释放资源方法
    public static void close(Connection con, Statement statement){

        if(con != null && statement != null){
            try {
                statement.close();
                //归还连接
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }

    public static void close(Connection con, Statement statement, ResultSet resultSet){

        if(con != null && statement != null && resultSet != null){
            try {
                resultSet.close();
                statement.close();
                //归还连接
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }

}

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Walter Savage Landor:strove with none,for none was worth my strife.Nature I loved and, next to Nature, Art:I warm'd both hands before the fire of life.It sinks, and I am ready to depart

                                                                                                                                                   ——W.S.Landor

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