closechannel.java

JAVA邮件系统

/* 
 *
 */

import java.io.*;
import java.text.*;
import java.sql.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

/**
 * 
 *
 * @author lizhaoshan
 */

public class CloseChannel extends HttpServlet {


    public void doGet(HttpServletRequest request,
                      HttpServletResponse response)
        throws IOException, ServletException
    {
		HtmlOut htmlOut = new HtmlOut (response);

		// 得到名字和口令
		String name,pass;

		Person person = new Person();
		person.setName (CommonMethods.GetUserName(request));
		pass = CommonMethods.GetUserPass (request);
		if( person.getName ()==null || (!person.checkPassword(pass)) )
		{
	    	htmlOut.setErrorID (htmlOut.SHOW_SIMPLE_MESSAGE ,"",
								"请先登录！","Login?action=reLog");
			htmlOut.outHtml();
			return;
		}
	
		String channelname = request.getParameter("channel");
		if( channelname==null ){
			htmlOut.setErrorID (htmlOut.SHOW_SIMPLE_MESSAGE  ,
							 "","不知关闭内容","Login");
			htmlOut.outHtml ();
			return;
		}

		DBOperater DB = new DBOperater ("userchannel");
		String queryString;
		queryString = "select pagenumber from userchannel where ( username='"
					+ CommonMethods.DealWithSQLParameter (person.getName())
					+ "' and channelid='" +
					CommonMethods.DealWithSQLParameter (channelname)+"')";
		ResultSet rs;
		int nPage=0;
	
		if( ( rs = DB.executeQuery  (queryString) )==null ){
			htmlOut.setErrorID (htmlOut.SHOW_SIMPLE_MESSAGE ,
							 "","未选此频道","Login");
			htmlOut.outHtml ();
			DB.close ();
			return;
		}
		else{
			try{
				if(rs.next()){
					nPage = rs.getInt (1);		
				}
			}
			catch(Exception e){
			}
		}
			
		queryString = "delete from userchannel where ( username='"
					+ CommonMethods.DealWithSQLParameter (person.getName())
					+ "' and channelid='" 
					+ (CommonMethods.DealWithSQLParameter(channelname))+ "')";
		DB.executeUpdate (queryString);
		DB.close ();
																				 
		htmlOut.setRedirect ("Login?p="+nPage);
		htmlOut.outHtml ();
    }
}