adminservlet.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.util.List;

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

import me.work.services.DBOperation;

public class AdminServlet extends HttpServlet {

	/**
	 * serialVersionUID
	 */
	private static final long serialVersionUID = 1L;
	/**
	 * ITEMS_OF_ONE_PAGE
	 */
	private static final int ITEMS_OF_ONE_PAGE = 2;
	/*
	 * (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 {
		// TODO Auto-generated method stub
		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 method = req.getParameter("method");
		DBOperation dbo = new DBOperation();
		if ("all".equals(method)) {
			// show all the message
			req.setAttribute("meth", "all");
			int begin;
			int count;
			// show 2 items a page
			try {
				// begining items
				String sb = req.getParameter("b");
				// end items
				String se = req.getParameter("e");
				count = dbo.getMsgCount(true);
				if(count % ITEMS_OF_ONE_PAGE == 0){
					req.setAttribute("pages", count / ITEMS_OF_ONE_PAGE);	
				}else{
					req.setAttribute("pages", count / ITEMS_OF_ONE_PAGE + 1);
				}
				
				
				if (sb != null && !"".equals(sb)) {
					begin = Integer.valueOf(sb).intValue() - ITEMS_OF_ONE_PAGE;
					if (begin < 1) {
						begin = 1;
					}else if(begin > count){
						begin = count - ITEMS_OF_ONE_PAGE + 1;
					}
					req.setAttribute("b", begin);
					req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
					//the current page
					req.setAttribute("c", begin/ITEMS_OF_ONE_PAGE + 1);
				} else if (se != null && !"".equals(se)) {
					begin = Integer.valueOf(se).intValue() + 1;
					if (begin < 1) {
						begin = 1;
					}else if(begin > count){
						begin = count - ITEMS_OF_ONE_PAGE + 1;
					}
					req.setAttribute("b", begin);
					req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
					//the current page
					req.setAttribute("c", begin/ITEMS_OF_ONE_PAGE + 1);
				} else {
					// intial
					begin = 1;
					req.setAttribute("b", begin);
					req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
					//the current page
					req.setAttribute("c", 1);
				}

			} catch (Exception e) {
				begin = 1;
				req.setAttribute("b", begin);
				req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
				//the current page
				req.setAttribute("c", 1);
			}

			try {
				List list = dbo.getMessagePageList(begin, ITEMS_OF_ONE_PAGE,true);
				req.setAttribute("msgList", list);
				req.getRequestDispatcher("./pages/adminPage.jsp").forward(req,
						resp);
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

		} else if ("un".equals(method)) {
			///*************************************************************
			//get unreplied messages
			///*************************************************************
			req.setAttribute("meth", "un");
			int begin;
			int count;
			// show 2 items a page
			try {
				// begining items
				String sb = req.getParameter("b");
				// end items
				String se = req.getParameter("e");
				count = dbo.getMsgCount(false);
				if(count % ITEMS_OF_ONE_PAGE == 0){
					req.setAttribute("pages", count / ITEMS_OF_ONE_PAGE);	
				}else{
					req.setAttribute("pages", count / ITEMS_OF_ONE_PAGE + 1);
				}
				
				
				if (sb != null && !"".equals(sb)) {
					begin = Integer.valueOf(sb).intValue() - ITEMS_OF_ONE_PAGE;
					if (begin < 1) {
						begin = 1;
					}else if(begin > count){
						begin = count - ITEMS_OF_ONE_PAGE + 1;
					}
					req.setAttribute("b", begin);
					req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
					req.setAttribute("c", begin/ITEMS_OF_ONE_PAGE + 1);
				} else if (se != null && !"".equals(se)) {
					begin = Integer.valueOf(se).intValue() + 1;
					if (begin < 1) {
						begin = 1;
					}else if(begin > count){
						begin = count - ITEMS_OF_ONE_PAGE + 1;
					}
					req.setAttribute("b", begin);
					req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
					req.setAttribute("c", begin/ITEMS_OF_ONE_PAGE + 1);
				} else {
					// intial
					begin = 1;
					req.setAttribute("b", begin);
					req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
					req.setAttribute("c", 1);
				}

			} catch (Exception e) {
				begin = 1;
				req.setAttribute("b", begin);
				req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
			}

			try {
				//get unreplied msg list
				List list = dbo.getMessagePageList(begin, ITEMS_OF_ONE_PAGE,false);
				req.setAttribute("msgList", list);
				req.getRequestDispatcher("./pages/adminPage.jsp").forward(req,
						resp);
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		} else if ("user".equals(method)) {
			req.setAttribute("meth", "user");
			int begin;
			int count;
			// show 2 items a page
			try {
				// begining items
				String sb = req.getParameter("b");
				// end items
				String se = req.getParameter("e");
				count = dbo.getUserCount();
				if(count % ITEMS_OF_ONE_PAGE == 0){
					req.setAttribute("pages", count / ITEMS_OF_ONE_PAGE);	
				}else{
					req.setAttribute("pages", count / ITEMS_OF_ONE_PAGE + 1);
				}
				
				
				if (sb != null && !"".equals(sb)) {
					begin = Integer.valueOf(sb).intValue() - ITEMS_OF_ONE_PAGE;
					if (begin < 1) {
						begin = 1;
					}else if(begin > count){
						begin = count - ITEMS_OF_ONE_PAGE + 1;
					}
					req.setAttribute("b", begin);
					req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
					req.setAttribute("c", begin/ITEMS_OF_ONE_PAGE + 1);
				} else if (se != null && !"".equals(se)) {
					begin = Integer.valueOf(se).intValue() + 1;
					if (begin < 1) {
						begin = 1;
					}else if(begin > count){
						begin = count - ITEMS_OF_ONE_PAGE + 1;
					}
					req.setAttribute("b", begin);
					req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
					req.setAttribute("c", begin/ITEMS_OF_ONE_PAGE + 1);
				} else {
					// intial
					begin = 1;
					req.setAttribute("b", begin);
					req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
					req.setAttribute("c", 1);
				}

			} catch (Exception e) {
				begin = 1;
				req.setAttribute("b", begin);
				req.setAttribute("e", begin + ITEMS_OF_ONE_PAGE - 1);
			}

			try {
				//get unreplied msg list
				List list = dbo.getUserList(begin, ITEMS_OF_ONE_PAGE);
				req.setAttribute("userList", list);
				req.getRequestDispatcher("./pages/adminPage.jsp").forward(req,
						resp);
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}

}