图书管理系统的dao层

dao层

package bean;

import java.sql.*;
import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.*;
import java.util.Date;


public class dao {
      
    public static Long between_days(String a, String b) {

        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");// �Զ���ʱ���ʽ

        Calendar calendar_a = Calendar.getInstance();// ��ȡ��������
        Calendar calendar_b = Calendar.getInstance();

        Date date_a = null;
        Date date_b = null;

        try {
            date_a = simpleDateFormat.parse(a);//�ַ���תDate
            date_b = simpleDateFormat.parse(b);
            calendar_a.setTime(date_a);// ��������
            calendar_b.setTime(date_b);
        } catch (Exception e) {
            e.printStackTrace();//��ʽ���쳣
        }

        long time_a = calendar_a.getTimeInMillis();
        long time_b = calendar_b.getTimeInMillis();

        long between_days = (time_b - time_a) / (1000 * 3600 * 24);//�����������

        return between_days;
    }
    
      public String passing(String account,String password) throws SQLException {          //login
          bd database=new bd();
          Connection connect=database.getlink();
          Statement state=null;
          ResultSet rsp=null;
          state=connect.createStatement();
          rsp=state.executeQuery("select * from name where code='"+account+"'and password='"+password+"'");
          if(rsp.next())
          {   System.out.print(rsp.getString("using"));
              return rsp.getString("using");}
            return "0";
      }
      public readerform selfcheck(String code) throws SQLException {
          readerform me=new readerform();
          bd database=new bd();
             Connection connect=database.getlink();
             Statement state=null;
          state=connect.createStatement();
          ResultSet rs = state.executeQuery("select * from reader where code='"+code+"'");
          if(rs.next()) {
          me.setCode(rs.getString("code"));
          me.setName(rs.getString("name"));    
          me.setSex(rs.getString("sex"));   
          me.setAcd(rs.getString("acd"));
          }
          return me;  
      }
      
      public int Iputreader(readerform w){
          bd database=new bd();
          Connection connect=database.getlink();
          Statement state=null;
          try {
            state=connect.createStatement();
           } catch (SQLException e) {System.out.print("sqlboom!
");}
          try {
            state.executeUpdate("INSERT INTO reader VALUES('"+w.getCode()+"','"+w.getName()+"','"+w.getSex()+"','"+w.getAcd()+"')");
            state.executeUpdate("INSERT INTO name VALUES('"+w.getCode()+"','0000','2')");
            return 1;
           } catch (SQLException e) {System.out.print("insert error!
");return 0;}           
      }
      
      public int Iputbook(bookform w){
          bd database=new bd();
          Connection connect=database.getlink();
          Statement state=null;
          try {
            state=connect.createStatement();
           } catch (SQLException e) {System.out.print("sqlboom!
");}
          try {
            state.executeUpdate("INSERT INTO books VALUES('"+w.getCode()+"','"+w.getName()+"','"+w.getMaster()+"','"+w.getOutput()+"','"+w.getMaxamount()+"','0')");
            return 1;
           } catch (SQLException e) {System.out.print("insert error!
");return 0;}           
      }
      
      public bookform[] viewall() {
          bd database=new bd();
              Connection connect=database.getlink();
              Statement state=null;
              try {
                state=connect.createStatement();
               } catch (SQLException e) {System.out.print("sqlboom!
");}
              bookform[] pop=new bookform[1000];
              for(int i=0;i<1000;i++) {
                  pop[i]=new bookform();
              }
              ResultSet rsp=null;
              try {
           rsp = state.executeQuery("select * from books");
           } catch (SQLException e) {System.out.print("rs.error");}
              try {
            for(int i=0;rsp.next();i++) {
                pop[i].setCode(rsp.getString("code"));
                pop[i].setName(rsp.getString("name"));   
                pop[i].setMaster(rsp.getString("master"));  
                pop[i].setOutput(rsp.getString("output"));  
                pop[i].setAmount(Integer.parseInt(rsp.getString("amount")));   
                pop[i].setMaxamount(Integer.parseInt(rsp.getString("maxamount")));   
            }
            } catch (SQLException e) {System.out.print("rsget.error");}
              return pop;
     }
      
      public int select(String student,String code) throws SQLException {
          int i=1;
          LocalDate date = LocalDate.now();
          DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd"); 
          String day=date.format(formatter);
           bd database=new bd();
              Connection connect=database.getlink();
              Statement state=null;
           state=connect.createStatement();Statement st = connect.createStatement();
           ResultSet rs = state.executeQuery("select count(*) from seekbook where student='"+student+"' and book='"+code+"'");
           rs.next();
           int result = rs.getInt(1);
           rs.close();
           ResultSet rsp = st.executeQuery("select * from  books where code='"+code+"'");
           int num=0;int maxnum=0;
           if(rsp.next()) {
           num=Integer.parseInt(rsp.getString("amount"));
           maxnum=Integer.parseInt(rsp.getString("maxamount"));
           System.out.print(result);
           System.out.print(num);
           
           }
           if(result==0&&(num<maxnum)){
               state.executeUpdate("INSERT INTO seekbook VALUES('"+student+code+"','"+code+"','"+student+"','"+day+"')");
               num++;
               state.executeUpdate("update books set amount='"+num+"' where code='"+code+"'");
           }else {
               i=0;    
           }
           return i;
    }
     
      public bookform[] viewonly(String name,String master) {
             bd database=new bd();
                 Connection connect=database.getlink();
                 Statement state=null;
                 try {
                   state=connect.createStatement();
                  } catch (SQLException e) {System.out.print("sqlboom!
");}
                 bookform[] pop=new bookform[1000];
                 for(int i=0;i<1000;i++) {
                     pop[i]=new bookform();
                 }
                 ResultSet rsp=null;
                 try {
              rsp = state.executeQuery("select * from books where name like '%"+name+"%' and master like '%"+master+"%'");
              } catch (SQLException e) {System.out.print("rs.error");}
                 try {
               for(int i=0;rsp.next();i++) {
                   pop[i].setCode(rsp.getString("code"));
                   pop[i].setName(rsp.getString("name"));   
                   pop[i].setMaster(rsp.getString("master"));  
                   pop[i].setOutput(rsp.getString("output"));  
                   pop[i].setAmount(Integer.parseInt(rsp.getString("amount")));   
                   pop[i].setMaxamount(Integer.parseInt(rsp.getString("maxamount")));   
               }
               } catch (SQLException e) {System.out.print("rsget.error");}
                 return pop;
        }
      
      public int date(String day1,String day2) {
          String between_dayInteger = ""+between_days(day1, day2);
          return Integer.parseInt(between_dayInteger);
      }
      
      public int refuse(String code,String book) throws SQLException {
          bd database=new bd();
              Connection connect=database.getlink();
              Statement state=null;
           state=connect.createStatement();
           state.executeUpdate("delete  from seekbook where student='"+code+"' and book='"+book+"'");
           return 1;
      }
      public seekform[] viewme(String code) throws SQLException {
           bd database=new bd();
           seekform[] pop=new seekform[1000];
              Connection connect=database.getlink();
              Statement state=null;
           state=connect.createStatement();
           ResultSet rsp = state.executeQuery("select * from seekbook where student='"+code+"'");
           for(int i=0; i<1000; i++)
           {pop[i] = new seekform();}
           for(int i=0;rsp.next();i++) {
                pop[i].setBook(rsp.getString("book"));
                pop[i].setDay(rsp.getString("day"));
                pop[i].setStudent(rsp.getString("student"));
            }
           return pop;
     }
     public seekform[] viewself(String code) throws SQLException {
           bd database=new bd();
           seekform[] pop=new seekform[1000];
              Connection connect=database.getlink();
              Statement state=null;
           state=connect.createStatement();
           ResultSet rsp = state.executeQuery("select * from seekbook where student='"+code+"'");
           for(int i=0; i<1000; i++)
           {pop[i] = new seekform();}
           for(int i=0;rsp.next();i++) {
               LocalDate date = LocalDate.now();
                  DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd"); 
                  String day=date.format(formatter);
                  if(date(rsp.getString("day"),day)>30) {
                pop[i].setBook(rsp.getString("book"));
                pop[i].setDay(rsp.getString("day"));
                pop[i].setStudent(rsp.getString("student"));
                  }else {
                   i--;
                  }
            }
           return pop;
     }
     public seekform[] viewas() throws SQLException {
           bd database=new bd();
           seekform[] pop=new seekform[1000];
              Connection connect=database.getlink();
              Statement state=null;
           state=connect.createStatement();
           ResultSet rsp = state.executeQuery("select * from seekbook");
           for(int i=0; i<1000; i++)
           {pop[i] = new seekform();}
           for(int i=0;rsp.next();i++) {
               LocalDate date = LocalDate.now();
                  DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd"); 
                  String day=date.format(formatter);
                  if(date(rsp.getString("day"),day)>30) {
                pop[i].setBook(rsp.getString("book"));
                pop[i].setDay(rsp.getString("day"));
                pop[i].setStudent(rsp.getString("student"));
                  }else {
                   i--;
                  }
            }
           return pop;
     }
      
      
}