needback.java

JAVA的MVC三层开发的图书馆管理系统。

package mypackage;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.PrintWriter;
import java.io.IOException;
import java.sql.*;
import javax.sql.DataSource;
import java.util.Vector;
import java.util.Calendar;

public class NeedBack extends HttpServlet 
{
  private static final String CONTENT_TYPE = "text/html; charset=GBK";

  public void init(ServletConfig config) throws ServletException
  {
    super.init(config);
  }

  public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    response.setContentType(CONTENT_TYPE);
    request.setCharacterEncoding("GBK");
    PrintWriter out = response.getWriter();
    
    String bookID = request.getParameter("bookID");
    String readerID = request.getParameter("readerID");
    DataSource ds = (DataSource)request.getSession().getServletContext().getAttribute("DataSrc");
    Connection conn = null;
    //Statement stmt = null;
    PreparedStatement pst = null;
    ResultSet rs = null;
    //Calendar time = Calendar.getInstance();
    //int year = time.get(Calendar.YEAR);
    //int month = time.get(Calendar.MONTH)+1;
    //int date = time.get(Calendar.DATE);
    String today = new FormatDate().nowDate();
    Date date = Date.valueOf(today);
    //String sql = "select * from lendview where isreturn = 1 and returndate < #"+month+"-"+date+"-"+year+"#" ;
    String sql = "select * from lendview where isreturn = 1 and returndate < ?";
    Vector result = new Vector();
    Lend lend;
    
    try{
      conn = ds.getConnection();
      //stmt = conn.createStatement();
      //rs = stmt.executeQuery(sql);
      pst = conn.prepareStatement(sql);
      pst.setDate(1, date);
      rs = pst.executeQuery();
      out.print(date);
      
      while(rs.next()){
        lend = new Lend();
        lend.bookID = rs.getString("bookid");
        lend.bookName = rs.getString("bookname");
        lend.readerID = rs.getString("readerid");
        lend.readerName = rs.getString("readername");
        lend.lenddate = rs.getDate("lenddate");
        lend.returndate = rs.getDate("returndate");
        lend.isreturn = rs.getInt("isreturn");
        result.add(lend);
      }
      rs.close();
      //stmt.close();
      pst.close();
      conn.close();
    }
    catch(SQLException e){
      System.out.println(e.getMessage());
    }
    request.setAttribute("result",result);
    request.getSession().getServletContext().getRequestDispatcher("NeedBack.jsp").forward(request, response);
  }
}