msgservlet.java

新闻,新闻类别管理,批量删除,不同的用户登陆

package cn.edu.zucc.news.servlet;

import java.io.IOException;

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

import myjsp.*;

import cn.edu.zucc.news.model.*;

public class MsgServlet extends HttpServlet {
	private WebMsgDAO dao = new WebMsgDAO();

	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		this.doPost(request, response);
	}

	private String listMsg(HttpServletRequest request) {
        try {
            request.setAttribute("objlist", dao.loadAllMsgs());
            return "/msg_list.jsp";
        } catch (Exception ex) {
            request.setAttribute("errormsg", ex.getMessage());
            return "/error.jsp";
        }
    }
	private String addMsg(HttpServletRequest request) {
        request.setAttribute("obj", new WebMsg());
        return "/msg_edit.jsp";
    }
	private String addMsgresult(HttpServletRequest request) {
        WebMsg msg = new WebMsg();
        String userid=(String)request.getSession().getAttribute("userid");
         //System.out.println(userid);
        String msgs=request.getParameter("msg");
        msg.setUserid(userid);
        msg.setMsg(msgs);
        try {
            this.dao.addMsg(userid,msgs);
            return this.listMsg(request);
        } catch (Exception ex) {
            request.setAttribute("errormsg", ex.getMessage());
            return "/error.jsp";
        }
    }
	private String deleteMsg(HttpServletRequest request) {
        try {
        	int msgid=Integer.parseInt(request.getParameter("msg_id"));
            this.dao.delMsg(msgid);
            return this.listMsg(request);
        } catch (Exception ex) {
            request.setAttribute("errormsg", ex.getMessage());
            return "/error.jsp";
        }
    }
	private String deleteMoreMsg(HttpServletRequest request) {
        try {
        	String[] checked=request.getParameterValues("ckb");
        	for(int i=0;i<checked.length;i++){
        		int msgid=Integer.parseInt(checked[i].toString());
        		System.out.println(msgid);
                this.dao.delMsg(msgid);
        	}
            return this.listMsg(request);
        } catch (Exception ex) {
            request.setAttribute("errormsg", ex.getMessage());
            return "/error.jsp";
        }
    }
	
	protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("gbk");
        String method = request.getParameter("method");
        //System.out.println(method);
        if (method == null)  method ="listMsg";
        String result="";
        if (method.equals("addMsg"))
            result = addMsg(request);
        else if (method.equals("addMsgresult"))
            result = addMsgresult(request);
        else if (method.equals("deleteMsg"))
            result = deleteMsg(request);
        else if (method.equals("deleteMoreMsg"))
            result = deleteMoreMsg(request);
        else
            result = listMsg(request);
        RequestDispatcher dispatcher = request.getSession().getServletContext().getRequestDispatcher(result);
        if (dispatcher != null)
            dispatcher.forward(request, response);
	}
	public void destroy() {
        // TODO Auto-generated method stub
        super.destroy();
        dao.release();
    }
}