使用单例模式创建DBConnection
package com.singleton;import java.sql.Connection;import java.sql.DriverManager;public class DBConnection {private static DBConnection dbc;private String url="jdbc:sqlserver://10.10.0.98:1433;databaseName=mydb"; private String user="username"; private String password="password";private Connection conn; //私有构造器,只允许内部实用,不允许在外面调用创建类实例private DBConnection(){}public static DBConnection getInstance(){if (dbc == null) {dbc = new DBConnection();}return dbc;}public Connection getConnection(){try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); if (conn == null){conn= DriverManager.getConnection(url,user,password);} }catch (Exception e){e.printStackTrace();}return conn;}}