bookretrun.java

基于jsp的图书管理系统的功能和实现

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*; 
import java.sql.*;
import java.sql.Date;
import data.LoginData;
public class BookRetrun extends HttpServlet{
	private static final String CONTENT_TYPE="text/html;charset=GBK";
	public void doPost(HttpServletRequest request,HttpServletResponse response)
	throws ServletException,IOException{
		String strSql=null;
		String strSql1=null;
		String stautes=null;
	    String date=null;
		ResultSet rs=null;
		Statement stmt=null;
		int result=0;
		int result1=0;
		int bcstatus=0;
		request.setCharacterEncoding("GBK");
    	String BhRnumber =request.getParameter("BhRnumber");
		String BhBnumber =request.getParameter("BhBnumber");
		String BhBname = request.getParameter("BhBname");
        HttpSession session =request.getSession(false);
         if(session==null)
        {
         response.sendRedirect("tushu/error.jsp");
         return;
        }
        session.setAttribute("Bhr",BhRnumber);
        session.setAttribute("Bhb", BhBname);
		LoginData loginData = new LoginData();
		Connection conn = loginData.getConn();
        try{
             
             stmt=conn.createStatement();
             strSql="SELECT * FROM Bcurrent WHERE BcBnumber='"+BhBnumber+"'"+"AND"+" "+"BcRnumber='"+BhRnumber+"'";
             rs=stmt.executeQuery(strSql);
             if(rs.next()){
             	   bcstatus=rs.getInt("Bcstatus");
             	   date=(String)rs.getString("Bctodate");
             	  
             	}
              else {
                      	stautes ="您借的书不在库,请下次借书!";
			   		  	session.setAttribute("Modify",stautes);
			   		    response.sendRedirect("tushu/RetrunBook_Sucess.jsp");
			   		}
			   /*****************************************************/		
			    if(bcstatus==0){
			   	
			   	         strSql="UPDATE Book SET Bstate=1"+" "+"WHERE Bnumber='"+BhBnumber+"'";
			   	         strSql1="UPDATE Bcurrent SET Bcstatus=1"+" "+"WHERE BcBnumber='"+ BhBnumber+"'";
                         result=stmt.executeUpdate(strSql);
                         result1=stmt.executeUpdate(strSql1);
                          if(result>0&&result1>0){
                          	   //strSql="insert into Bhistory(BhRnumber,BhBnumber,BhBname) values('"+BhRnumber+"','"+BhBnumber+"','"+BhBname+"')";
		                       strSql="insert into Bhistory(BhRnumber,BhBnumber,Bhtodate,BhBname) values('"+BhRnumber+"','"+BhBnumber+"','"+date+"','"+BhBname+"')";
		                       result=stmt.executeUpdate(strSql);
		                       if(result>0){
		                       	    stautes ="还书成功!";
			   	  	                session.setAttribute("Modify",stautes);
			   		   	            response.sendRedirect("tushu/RetrunBook_Sucess.jsp");
		                       	}
		                       else{
		                       	   strSql="UPDATE Book SET Bstate=0"+" "+"WHERE Bnumber='"+BhBnumber+"'";
		                       	   strSql1="UPDATE Bcurrent SET Bcstatus=0"+" "+"WHERE BcBnumber='"+ BhBnumber+"'";
		                  	       result=stmt.executeUpdate(strSql);
		                  	       result1=stmt.executeUpdate(strSql1);
             	   	               stautes ="还书失败,系统问题,请下次还书!";
			   	  	               session.setAttribute("Modify",stautes);
			   		               response.sendRedirect("tushu/RetrunBook_Sucess.jsp");	
		                       	}
		                         
                          	  
                          	}
                          else{
                          	
                          	    stautes ="系统问题，请下次在还!";
			   		  	        session.setAttribute("Modify",stautes);
			   		    	    response.sendRedirect("tushu/RetrunBook_Sucess.jsp");
                          	}
			   	
			   	}
			   	else{
			   		    stautes ="您还的书以还,请核实!";
			   	  	    session.setAttribute("Modify",stautes);
			   		    response.sendRedirect("tushu/RetrunBook_Sucess.jsp");	
			   		  
			   		}
			   
		   }catch(Exception ex){
		   	ex.printStackTrace();
		   	}
		
		}
		public void destroy(){
			}
	
	}