c3p0 Druid

package datasource;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.junit.Test;

import java.beans.PropertyVetoException;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

/**
 * 演示c3p0的使用
 */
public class C3p0_ {
    @Test
    public void test() throws IOException, PropertyVetoException, SQLException {
        //1.创建一个数据源对象
        ComboPooledDataSource comboPooledDataSource = new ComboPooledDataSource();
        //2.通过配置文件获取相关连接
        Properties properties = new Properties();

        properties.load(new FileInputStream("src\\re.properties"));
        String user = properties.getProperty("user");
        String password = properties.getProperty("password");
        String url = properties.getProperty("url");
        String driver = properties.getProperty("driver");

        //给数据源comboDataSource  设置相关的参数
        //下面连接的管理就是有comboDataSource 来管理
        comboPooledDataSource.setDriverClass(driver);
        comboPooledDataSource.setJdbcUrl(url);
        comboPooledDataSource.setUser(user);
        comboPooledDataSource.setPassword(password);

        //设置的连接数  set connection number
        comboPooledDataSource.setInitialPoolSize(10);//ten connection is created
        comboPooledDataSource.setMaxPoolSize(50);//max size is 50;

        Connection connection = comboPooledDataSource.getConnection();
        System.out.println("connection is completed");
        connection.close();
    }

    //second :create connection by using model
    //1.we  should paste c3po.config.xml which is provided for c3p0 to src contents
    //2.改文件定义了相关的参数。
    @Test
    public void testc3p002() throws SQLException {
        ComboPooledDataSource hello = new ComboPooledDataSource("hello");
        hello.getConnection();
        System.out.println("ok");
        hello.close();
    }
}

package datasource;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.sql.Connection;
import java.util.Properties;

public class testDruid {
    //1加入Druid  jar  包
    //2.加入配置文件 druid.properties,将文件拷贝到src目录
    //3.创建properties文件
    public void testDruid() throws Exception {
        Properties properties = new Properties();
        properties.load(new FileInputStream("src\\druid.properties"));
        //创建一个指定参数的数据库连接池，就像当于是自己的连接池。
        DataSource dataSource = DruidDataSourceFactory.createDataSource(properties);
        Connection connection = dataSource.getConnection();
        System.out.println("连接成功");
        connection.close();

    }

}

jdbc.Utils

package com.wgs.jdbc.Utils;


import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;
import java.sql.*;

/**
 *完成mysql的连接和关闭资源。
 */
public class JDBCUtils {
    private static String user;
    private static String password;
    private static String url;
    private static String driver;
    //在static代码块中实现初试化
    static{

            Properties properties = new Properties();
        try {
            properties.load(new FileInputStream("src\\re.properties"));
        } catch (IOException e) {
            e.printStackTrace();
        }
        user = properties.getProperty("users");
            password = properties.getProperty("password");
            url = properties.getProperty("url");
            driver = properties.getProperty("driver");
        try {
            Class.forName(driver);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }


    }
    //连接数据库
    public static Connection getConnection(){
        try {
            Connection connection = DriverManager.getConnection(url, user, password);
            return connection;
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    //关闭相关的资源，
    public static void close (ResultSet set, PreparedStatement statement, Connection connection){
        //关闭结果集
        try {
            if (set != null){
                set.close();
            }

            if (statement != null){
                statement.close();
            }

            if (connection !=null){
                connection.close();
            }
        } catch (SQLException throwables) {
            throw new RuntimeException(throwables);
        }
    }
}