placeorderservlet.java

这是个用JSP开发WAP的实例

import java.io.*;
import javax.servlet.http.*;
import javax.servlet.*;
import javax.rmi.*;
import javax.naming.*;
import java.util.*;
import java.sql.*;
import javax.sql.*;


public class PlaceOrderServlet extends HttpServlet
{
	Context ic;
	OrderHome home;
	javax.sql.DataSource ds;
	
	public void init() throws ServletException
	{
		try
		{
			System.out.println("trying to get initial context");
			ic = (InitialContext) getInitialContext();
			System.out.println("Got InitContext");
			ds = (javax.sql.DataSource)ic.lookup("wapDB");
			System.out.println("lookup for ds succeeded");
			
			Object objRef = ic.lookup("Order");
			home = (OrderHome)PortableRemoteObject.narrow(objRef,OrderHome.class);
			System.out.println("Got Home");
			
		}catch(Exception e){
			System.out.println("Error in init of PlaceOrderServlet: " + e.getMessage());
			e.printStackTrace();
		}
	
	
	}

	public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException
	{
	
		try
		{
			HttpSession session = req.getSession(false);
			String salesman_id = (String)session.getAttribute("SalesmanId");
			System.out.println("salesmanid: " + salesman_id);
			
			String client_id = (String)session.getAttribute("ClientId");
			System.out.println("clientid: " + client_id);

			String quantity = (String)req.getParameter("quant");
			System.out.println("quant: " + quantity);

			String item_id = (String)session.getAttribute("ItemId");
			System.out.println("itemid: " + item_id);

			String maxOrderId = null;
			Connection conn = ds.getConnection();
			//Get the max order id and then calculate the new order id
			PreparedStatement s = conn.prepareStatement("SELECT MAX(ID) FROM ORDER_INFO");
			s.executeQuery();
			ResultSet rs = s.getResultSet();
			while(rs.next())
			{
				maxOrderId = rs.getString(1);
			}
			System.out.println("length of maxorderid: " + maxOrderId.length());
			maxOrderId = maxOrderId.trim();
			System.out.println("length of maxorderid: " + maxOrderId.length());

			long orderId = Long.parseLong(maxOrderId);
			orderId++;
			String newOrderId = "" + orderId;
			System.out.println("order id: " + newOrderId);
			Order order = home.create(newOrderId,quantity,item_id,salesman_id,client_id);
			
			String time = order.getTime();
			session.setAttribute("OrderId",order.getPrimaryKey());
			session.setAttribute("OrderTime",time);
			res.sendRedirect(res.encodeURL("/Confirm.jsp"));
			
			
			
		}catch(Exception e)
		{
			
			System.out.println("Error in doGet of PlaceOrderServlet: " + e.getMessage());
			e.printStackTrace();
		}
				
	}
	
	private Context getInitialContext() throws NamingException
   {
    	Properties h = null;
    	try {
      // Get an InitialContext
      	h = new Properties();
      	h.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");
	      h.put(Context.PROVIDER_URL, "t3://localhost:7001");
      	
	      
    	}catch(Exception ne) {
      	System.out.println("Unable to get an initial context");
    	}
		return new InitialContext(h);   
   }
}