图书管理系统

package ActionServlet; import java.io.IOException; import java.io.PrintWriter; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; import java.io.IOException; import java.io.PrintWriter; import java.nio.charset.Charset; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import cf.h.hcfBook.dbc.DBconnection; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.swing.JOptionPane; import javax.swing.plaf.basic.BasicInternalFrameTitlePane.SystemMenuBar; import javax.swing.text.AbstractDocument.Content; import com.sun.corba.se.spi.orbutil.fsm.Guard.Result; import com.sun.crypto.provider.RSACipher; import cf.h.hcfBook.dbc.DBconnection; public class BorrowBk extends HttpServlet{ public BorrowBk() { super(); // TODO Auto-generated constructor stub } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { /*int n=JOptionPane.showConfirmDialog(null,"确认借阅该图书？","确认借阅该图书",JOptionPane.YES_NO_OPTION); if(n==JOptionPane.YES_OPTION){*/ // TODO Auto-generated method stub DBconnection dbcon = new DBconnection(); Connection conn = dbcon.getConnection(); resp.setContentType("text/html;charset=utf-8"); resp.setCharacterEncoding("utf-8"); req.setCharacterEncoding("utf-8"); resp.setHeader("Content-type", "text/html;charset=UTF-8"); PrintWriter wout=resp.getWriter(); String username=req.getSession().getAttribute("username")+""; String bookid=req.getParameter("bookid"); Statement insertbkStm; /*Date nowdate=new Date(); Calendar calendar=new Calendar(); calendar.setTime(nowdate);*/ //获取当前时间和归还时间 Calendar currDate = Calendar.getInstance(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); String borrowdate = sdf.format(currDate.getTime()); currDate.add(Calendar.MONTH, 1); String returndate = sdf.format(currDate.getTime()); /*String borrowdate="1";*/ /*String returndate="1";*/ String bstate="已借阅"; String state="借阅成功"; /*String delsql="delete from borrow where bookid='"+bookid+"' and username='"+username+"'";*/ String nowsql="select count(*) cn from borrow where username='" + username + "'"+" group by username"; ResultSet rs; int count=0; try { PreparedStatement stm=conn.prepareStatement(nowsql); rs = stm.executeQuery(); if(rs.next()){ count=rs.getInt("cn"); } } catch (SQLException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } if(count>=10){ wout.println("<script>alert('借阅已达上限，请先归还');window.location.href='returnbook.jsp'</script>"); } else{ String insertbksql="insert into borrow(username,bookid,borrowdate,returndate,state) values('"+username+"','"+bookid+"','"+borrowdate+"','"+returndate+"','"+state+"')"; String updatebksql="update book set kucun=kucun-1,borrowcount=borrowcount+1 where bookid="+bookid; /* System.out.println(updatebksql);*/ /* String updatesbksql="update borrow set state='"+state+"' where bookid="+bookid;*/ /*System.out.println(updatesbksql);*/ try { insertbkStm = conn.createStatement(); /* insertbkStm.execute(delsql);*/ insertbkStm.execute(insertbksql); insertbkStm.execute(updatebksql); /*insertbkStm.execute(updatesbksql);*/ } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } wout.println("<script>alert('借阅成功，请及时归还!');window.location.href='borrowbook.jsp'</script>"); wout.flush(); wout.close(); } /*} else{ resp.sendRedirect("borrowbook.jsp"); }*/ } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { // TODO Auto-generated method stub this.doGet(req, resp); } }