Scala之Demo1

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1.创建Connection的object，在scala里面称为单例对象

package com.testimport java.sql.DriverManagerimport java.sql.Connectionobject SingleMySqlConn {  private var driver = "com.mysql.jdbc.Driver"  private var url = "jdbc:mysql://localhost/bms"  private var connection: Connection = null;  def getConnection(username: String, password: String): Connection = {    if (connection == null) {      try {               Class.forName(driver)        connection = DriverManager.getConnection(url, username, password)        connection      }       catch{                case e=>e.printStackTrace()        null      }    } else {      connection    }  }}

2.客户端调用连接MySQL单例对象的方法

package com.testimport java.sql.DriverManagerimport java.sql.Connectionobject ScalaMySql {  def main(args: Array[String]): Unit = {       val connection = SingleMySqlConn.getConnection("root", "123")    if (connection != null) {      val statement = connection.createStatement()      val resultSet = statement.executeQuery("SELECT * FROM bms_appuser")      while (resultSet.next()) {        val userName = resultSet.getString("userName")        val userCard = resultSet.getString("userCard")        println("userName, <span style="font-family: Arial, Helvetica, sans-serif;">userCard </span>= " + userName + ", " + userCard)      }      connection.close()    }      }}

3.简单测试结果

</pre><pre name="code" class="java">userName, userCard = zhao, XSJKLKLuserName, userCard = cui, <span style="font-family: Arial, Helvetica, sans-serif;">XSJKLKK</span>

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