checkuser.java

商品销售管理系统工程代码

package method;

import java.sql.ResultSet;
import java.sql.Connection;
import java.sql.PreparedStatement;
import data.*;

public class CheckUser {

  private String name = "";
  private String password = "";
  private int state = 1;

  public CheckUser(String name, String password, int state) {
   this.name = name;
   this.password = password;
   this.state = state;
  }

  //检查用户的方法
  public String checkLogin(){
    String message = "";
    Connection conn = null;
    try{
      LoginData loginData = new LoginData();
      //取得数据库连接
      conn = loginData.setupConn();
      //创建数据表的查询SQL语句
      String sql = "select * from login where userName = ? and userPassword = ? " +
                   "and userState = ?";
      //创建数据集
      ResultSet rs;
      //创建查询的PreparedStatement类
      PreparedStatement queryPs = conn.prepareStatement(sql);
      //设置查询类的3个参数
      queryPs.setString(1,name);
      queryPs.setString(2,password);
      queryPs.setInt(3,state);
      //执行查询操作
      rs = queryPs.executeQuery();
      if(rs.next()){
        //取得用户名和密码
        String nameData = rs.getString(2);
        String passwordData = rs.getString(3);
        //检查用户名和密码的大小写
        if ( (name.compareTo(nameData) == 0) &&
            (password.compareTo(passwordData) == 0)) {
          if(state == 0){
            message = "0";    //管理员用户信息
          }else{
            message = "1";    //用户信息
          }
        }else{
          message = "-1";     //登陆不成功信息
        }
      }else{
        message = "-1";       //登陆不成功信息
      }
    }catch(Exception e){
      e.printStackTrace();
      return e.getMessage();
    }finally{
      try{conn.close();} catch(Exception e){}
    }
    return message;
  }
}