package action;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionError;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionServlet;
import bussness.UserInfoBo;
import entity.UserInfoForm;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

public final class LogonAction extends Action {

  public ActionForward execute(ActionMapping mapping,
         ActionForm form,
         HttpServletRequest request,
         HttpServletResponse response)
         throws IOException, ServletException {
    UserInfoForm userInfoForm = (UserInfoForm) form;
    //從web層獲得用戶名和口令
    String username = userInfoForm.getUsername().trim();
    String password = userInfoForm.getPassword().trim();
    //聲明錯(cuò)誤集對象
    ActionErrors errors = new ActionErrors();
    //聲明數(shù)據(jù)源和連接對象
    DataSource dataSource;
    Connection cnn=null;

    //校驗(yàn)輸入
    if(username.equals("")){
      ActionError error=new ActionError("error.missing.username");
      errors.add(ActionErrors.GLOBAL_ERROR,error);
    }
    if(password.equals("")){
      ActionError error=new ActionError("error.missing.password");
      errors.add(ActionErrors.GLOBAL_ERROR,error);
    }

    //調(diào)用業(yè)務(wù)邏輯
    if(errors.size()==0){
      String validated = "";
      try{
        //取得數(shù)據(jù)庫連接
        dataSource = getDataSource(request,"A");
        cnn = dataSource.getConnection();

        UserInfoBo userInfoBo=new UserInfoBo(cnn);
        validated =userInfoBo.validatePwd(username,password);
        if(validated.equals("match")){
          //一切正常就保存用戶信息并轉(zhuǎn)向成功的頁面
          HttpSession session = request.getSession();
          session.setAttribute("userInfoForm", form);
                return mapping.findForward("success");
        }
      }

      catch(Throwable e){
        //處理可能出現(xiàn)的錯(cuò)誤
        e.printStackTrace();
        ActionError error=new ActionError(e.getMessage());
        errors.add(ActionErrors.GLOBAL_ERROR,error);
      }
    }
    //如出錯(cuò)就轉(zhuǎn)向輸入頁面，并顯示相應(yīng)的錯(cuò)誤信息
    saveErrors(request, errors);
    return new ActionForward(mapping.getInput());
  }
}

package bussness;

import entity.UserInfoForm;
import java.sql.Connection;
import java.sql.SQLException;
import java.lang.Exception;
import db.UserInfoDao;

public class UserInfoBo {
  private Connection cnn=null;

  public UserInfoBo(Connection cnn){
    this.cnn=cnn;
  }

  public String validatePwd(String username,String password){

    String validateResult="";
   
    try{
      UserInfoDao userInfoDao = new UserInfoDao(cnn);
      validateResult=userInfoDao.validatePwd(username,password);
      if(validateResult.equals("error.logon.invalid")){
        //如果用戶名與口令不匹配則報(bào)此錯(cuò)
        throw new RuntimeException("error.logon.invalid"); 
      }
      else if(validateResult.equals("error.removed.user")){
        //如果找不到用戶則報(bào)此錯(cuò)，這樣用戶看到的出錯(cuò)信息會(huì)更詳細(xì)
        throw new RuntimeException("error.removed.user"); 
      }
    }
    catch(Exception e){
      throw new RuntimeException(e.getMessage());
    }
    finally{
      try{
        if(cnn!=null){
          cnn.close();
        }
      }
      catch(SQLException sqle){
        sqle.printStackTrace();
        throw new RuntimeException("error.unexpected");
      }
    }
    return validateResult;
  }
}

package db;
import entity.UserInfoForm;
import java.sql.*;

public class UserInfoDao {
  private Connection con;

  public UserInfoDao(Connection con) {
    this.con=con;
  }
  
  public String validatePwd(String username,String password){
    PreparedStatement ps=null;
    ResultSet rs=null;
    String validated="error.logon.invalid";
    UserInfoForm userInfoForm=null;
    String sql="select * from userInfo where username=?";
    try{
      if(con.isClosed()){
        throw new IllegalStateException("error.unexpected");

      }
      ps=con.prepareStatement(sql);
      ps.setString(1,username);
      rs=ps.executeQuery();
      if(rs.next()){
        if(!rs.getString("password").trim().equals(password)){
          return validated;//口令不正確返回口令不匹配信息
          
        }
        else{

          validated = "match";//口令正確返回口令匹配信息
          return validated;
        }
      }else{
        
        validated="error.removed.user";//沒有找到該用戶
        return validated;
        
      }

    }catch(SQLException e){
        e.printStackTrace();
        throw new RuntimeException("error.unexpected");
    }finally{
      try{
        if(ps!=null)
          ps.close();
        if(rs!=null)
          rs.close();
      }catch(SQLException e){
        e.printStackTrace();
        throw new RuntimeException("error.unexpected");
      }
    }
  }
}