package jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBConnection {
 public Connection getConnection(){
  Connection conn = null;
  String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
  String url = "jdbc:sqlserver://localhost:1433;DatabaseName = mp";
  String user = "sa";
  String password = "sa";
  
  try{
  Class.forName(driverName);
  conn = DriverManager.getConnection(url,user,password);
  if(conn!=null){
   System.out.println("ok");
  }
  }catch(Exception e){
   e.printStackTrace();
   System.out.println("false");
  }
  return conn;
 }
 public void closeConnection(Connection conn){
  if(conn!=null){
   try {
    conn.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
 }
 public static void main(String args[]){
  DBConnection dbc = new DBConnection();
  Connection conn = null;
  conn = dbc.getConnection();
 }
}
第二种方法：

package jdbc;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

public class DBConnection {
    //配置文件名
 private static String CONFIG_FILENAME="config.properties";
 //配置文件
 private Properties prop = null;
 //连接数据库的驱动程序
 private String driverName="";
 //配置数据库的 url,拥护名和密码
 private String url="";
 private static String user="";
 private static String password="";
 /**
  * 构造函数，从配置文件中获取连接数据库的信息
  */
 public DBConnection(){
  prop = new Properties();
  //度曲文件信息
  InputStream in = jdbc.DBConnection.class.getResourceAsStream("/"+CONFIG_FILENAME);
  try {
   prop.load(in);
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  //驱动程序名称
  driverName = prop.getProperty("DataBaseDrivers").trim();
  user = prop.getProperty("DataBaseUser");
  password = prop.getProperty("DataBaseUserPassword");
  url = getDBURL();
  //装载驱动程序
  try {
   Class.forName(driverName).newInstance();
  } catch (InstantiationException e) {
   e.printStackTrace();
  } catch (IllegalAccessException e) {
   e.printStackTrace();
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  }
 }
  /**
   * 从属性文件中获取信息组装数据库连接的URL
   */
  private String getDBURL(){
   if(prop.getProperty("DataBaseType").equals("SQLServer")){
    return "jdbc:sqlserver://"+prop.getProperty("DataBaseServerName")+":"+prop.getProperty("DatabaseServerPort")+";"+"SelectMode=cursor;DataBaseName="+prop.getProperty("DataBaseName");
               }
   return url;
   }
   /**
    * 返回数据库连接
    */
   public static Connection getConnection() throws SQLException{
    return DriverManager.getConnection(user,password,user);
    }
   public static void main(String[] args){
    Connection conn = null;
    System.out.println("ok");
   }
 }