frontcontroller.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;

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

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

  public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    response.setContentType(CONTENT_TYPE);
    request.setCharacterEncoding("GBK");
    if(request.getParameter("task") == null)
      ctx.getRequestDispatcher("index.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("validate") == 0)
      ctx.getNamedDispatcher("Validate").forward(request, response);
    if(request.getSession().getAttribute("validate") == null)
      ctx.getRequestDispatcher("Login.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("addNewBook") == 0)
      ctx.getRequestDispatcher("AddNewBook.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("saveAddNewBook") == 0)
      ctx.getNamedDispatcher("AddNewBook").forward(request, response);
    if(request.getParameter("task").compareTo("deleteBook") == 0)
      ctx.getNamedDispatcher("DeleteBook").forward(request, response);
    if(request.getParameter("task").compareTo("searchBook") == 0)
      ctx.getRequestDispatcher("SearchBook.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("saveSearchBook") == 0)
      ctx.getNamedDispatcher("SearchBook").forward(request, response);
    if(request.getParameter("task").compareTo("listBook") == 0)
      ctx.getNamedDispatcher("ListBook").forward(request, response);
    if(request.getParameter("task").compareTo("searchBook") == 0)
      ctx.getNamedDispatcher("SearchBook").forward(request, response);
    if(request.getParameter("task").compareTo("addNewReader") == 0)
      ctx.getRequestDispatcher("AddNewReader.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("saveAddNewReader") == 0)
      ctx.getNamedDispatcher("AddNewReader").forward(request, response);
    if(request.getParameter("task").compareTo("deleteReader") == 0)
      ctx.getRequestDispatcher("DeleteReader.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("saveDeleteReader") == 0)
      ctx.getNamedDispatcher("DeleteReader").forward(request, response);
    if(request.getParameter("task").compareTo("searchReader") == 0)
      ctx.getRequestDispatcher("SearchReader.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("saveSearchReader") == 0)
      ctx.getNamedDispatcher("SearchReader").forward(request, response);
    if(request.getParameter("task").compareTo("listReader") == 0)
      ctx.getNamedDispatcher("ListReader").forward(request, response);
    if(request.getParameter("task").compareTo("searchReader") == 0)
      ctx.getNamedDispatcher("SearchReader").forward(request, response);
    if(request.getParameter("task").compareTo("modifyReader") == 0)
      ctx.getRequestDispatcher("ModifyReader.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("saveModifyReader") == 0)
      ctx.getNamedDispatcher("ModifyReader").forward(request, response);
    if(request.getParameter("task").compareTo("lendInfo")  == 0)
      ctx.getNamedDispatcher("LendInfo").forward(request, response);
    if(request.getParameter("task").compareTo("lendBook") == 0)
      ctx.getRequestDispatcher("LendBook.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("saveLendBook") == 0)
      ctx.getNamedDispatcher("LendBook").forward(request, response);
    if(request.getParameter("task").compareTo("listLendBook") == 0)
      ctx.getNamedDispatcher("AllLendBook").forward(request, response);
    if(request.getParameter("task").compareTo("returnBook") == 0)
      ctx.getRequestDispatcher("ReaderReturn.jsp").forward(request, response);
    if(request.getParameter("task").compareTo("returnInfo") == 0)
      ctx.getNamedDispatcher("ReturnInfo").forward(request, response);
    if(request.getParameter("task").compareTo("saveReturnBook") == 0)
      ctx.getNamedDispatcher("ReturnBook").forward(request, response);
    if(request.getParameter("task").compareTo("needBack") == 0)
      ctx.getNamedDispatcher("NeedBack").forward(request, response);
  }
}