JDBC连接数据库(单例设计模式)

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
//单例设计模式
public class ConnectionFactory {
//创建一个自身的实例
private static ConnectionFactory connectionFactory = new ConnectionFactory();
//注册驱动程序
private ConnectionFactory()//使用private而不是public
{
try
{
Class.forName("com.mysql.jdbc.Driver");//如果是其他的数据库则做相应的更改
}
catch (Exception e)
{
System.out.println(e.getMessage());
}
}
//返回一个Connection
public static Connection getConnection() throws SQLException
{
String url = "jdbc:mysql://localhost:3306/mybookmanagment";//如果是其他的数据库则做相应的更改
return DriverManager.getConnection(url, "root", "123456");
}

//关闭Connection
public static void close(Connection connection)throws SQLException
{
if(connection != null && !connection.isClosed())
{
connection.close();
}
}
//关闭Statement
public static void close(Statement statement)throws SQLException
{
if(statement != null && !statement.isClosed())
{
statement.close();
}
}
//关闭ResultSet
public static void close(ResultSet resultSet) throws SQLException
{
if(resultSet != null && !resultSet.isClosed())
{
resultSet.close();
}
}
}