replyservlet.java

简单的流言板系统,用myeclipse进行编写的,采用简单的jstl+javabean+servlet+jsp,属于三层架构.

package me.work.servlets;

import java.io.IOException;
import java.sql.SQLException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import me.work.beans.MessageBean;
import me.work.services.DBOperation;

public class ReplyServlet extends HttpServlet {

	/*
	 * (non-Javadoc)
	 * 
	 * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest,
	 *      javax.servlet.http.HttpServletResponse)
	 */
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		doPost(req, resp);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest,
	 *      javax.servlet.http.HttpServletResponse)
	 */
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		String msgID = req.getParameter("msgID");
		String content = req.getParameter("content");
		String method = req.getParameter("method");
		req.setAttribute("msgID", msgID);

		int id;
		if (msgID != null && !"".equals(msgID.trim())) {
			try {
				id = Integer.valueOf(msgID).intValue();
			} catch (Exception e) {
				// TODO: handle exception
				id = 0;
			}
		} else {
			id = 0;
		}
		DBOperation dbo = new DBOperation();
		HttpSession se = req.getSession();

		// delete reply
		if (method != null && method.equals("delete")) {
			String repID = req.getParameter("id");
			try {
				if (dbo.deleteReply(Integer.valueOf(repID).intValue(), id)) {
					List replyList;

					replyList = dbo.getReplyListOfSpecifiedMessage(id);

					MessageBean msg = dbo.getMessageByID(id);
					req.setAttribute("msg", msg);
					req.setAttribute("info", "delete reply successfully!");
					req.setAttribute("replyList", replyList);
					req.getRequestDispatcher("./pages/reply.jsp").forward(req,
							resp);
				} else {
					List replyList;

					replyList = dbo.getReplyListOfSpecifiedMessage(id);
					MessageBean msg = dbo.getMessageByID(id);
					req.setAttribute("msg", msg);
					req.setAttribute("info", "delete reply failed");
					req.setAttribute("replyList", replyList);
					req.getRequestDispatcher("./pages/reply.jsp").forward(req,
							resp);
				}
			} catch (NumberFormatException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (ClassNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (Exception e) {
				// TODO: handle exception
				e.printStackTrace();
			}
			return;
		}

		if (!(content != null && !content.trim().equals(""))) {
			req
					.setAttribute("info",
							"You must enter some words before submit!");
			List replyList;
			try {
				replyList = dbo.getReplyListOfSpecifiedMessage(id);
				MessageBean msg = dbo.getMessageByID(id);
				req.setAttribute("msg", msg);
				req.setAttribute("replyList", replyList);
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

			req.getRequestDispatcher("./pages/reply.jsp").forward(req, resp);
			return;
		}
		try {
			if (dbo.replyMessage(id, se.getAttribute("userName").toString(),
					content)) {
				List replyList;

				replyList = dbo.getReplyListOfSpecifiedMessage(id);
				MessageBean msg = dbo.getMessageByID(id);
				req.setAttribute("msg", msg);
				req.setAttribute("info", "Reply successfully!");
				req.setAttribute("replyList", replyList);
				req.getRequestDispatcher("./pages/reply.jsp")
						.forward(req, resp);
				return;
			} else {
				List replyList;

				replyList = dbo.getReplyListOfSpecifiedMessage(id);
				MessageBean msg = dbo.getMessageByID(id);
				req.setAttribute("msg", msg);
				req.setAttribute("replyList", replyList);
				req.setAttribute("info", "Some error occured while insert DB");
				req.getRequestDispatcher("./pages/reply.jsp")
						.forward(req, resp);
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}
}