java-mysql

类名DBHelper：

package collect;

import java.sql.Connection;
import java.sql.DriverManager;

public class DBHelper {
    private static final String driver="com.mysql.jdbc.Driver";  //数据库驱动
     //连接数据库的URL地址
    private static final String url="jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8";
    private static final String username="root";
    private static final String password="root";
    private static Connection conn=null;
   
    //静态加载块负责加载驱动
    static{
        try{
            Class.forName(driver);
        }
        catch(Exception ex){
            ex.printStackTrace();
        }
    }
    
    //单例模式返回数据库对象
    public static Connection getConnection() throws Exception{
        if(conn==null){
            conn=DriverManager.getConnection(url,username,password);
            return conn;
        }
        return conn;
    }
    
    public static void main(String[] args){
        try{
            Connection conn=DBHelper.getConnection();
            if(conn!=null){
                System.out.println("数据库连接成功");
            }else{
                System.out.println("数据库连接失败");
            }
          }
        catch(Exception ex){
            ex.printStackTrace();
        }
    }
}