boardbbs.java

在学校做的第一个jsp专周论坛,用了些ajax技术.

package com.service;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Iterator;
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 com.dao.*;
import com.data.*;

public class boardbbs extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public boardbbs() {
		super();
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
  
	response.setContentType("text/xml;charset=utf-8");
	response.setHeader("Cache-Control","no-cache"); 
	PrintWriter out = response.getWriter();
	request.setCharacterEncoding("UTF-8"); 
	StringBuffer backInf=new StringBuffer();
	HttpSession sess=request.getSession(true);
	
	String indentity=null;
	indentity=(String)sess.getAttribute("indentity");
	
	if(indentity==null){
		indentity="yonghu";
	}
	System.out.println("indentity:"+indentity);
	
	String condition=request.getParameter("condition");
	
  String order=request.getParameter("order");
  StringBuffer sql=new StringBuffer();
  sql.append("select * from bbs ");
  //选择条件
  System.out.println(condition+order);
  boolean a=false;
  if(condition.equals("shot")){
  	sql.append("where bbshot=1 ");//加精
  	a=true;
  }else
  if(condition.equals("putong")){
  	sql.append("where bbshot=0 ");//未加精
      a=true;
  }
  
  //条件二版面
 int con;
 
 
 String name=(String)sess.getAttribute("name");
 Boards board=BoardDao.getBoardDao(name);
 con=board.getBoard_id();
 if(con!=-1){
  	if(a){
  	 sql.append("and board_id="+con+" " );
      }else{
       sql.append("where board_id="+con+" ");	
      }
  }
  //排序方式
  if(order.equals("bbshits")){
  	sql.append("order by bbshits desc");//点击率
  }else
  if(order.equals("bbsrecount")){
  	sql.append("order by bbsrecount desc");//回复数量
  }else
  if(order.equals("bbsdata")){
  	sql.append("order by 'bbsdata' desc");//发表时间
  }else
  if(order.equals("bbsredata")){
  	sql.append("order by 'bbsredata' desc");//回复时间
  }
  
  //获取显示的页数
  int page=Integer.parseInt(request.getParameter("page"));
  //int pageSize=Integer.parseInt((String)sess.getAttribute("pageSize"));
  int cupage=0;
  if(page==-2||page==-3){
  	
  	cupage=(Integer)sess.getAttribute("currentPage");
  	
  }
  int pageSize=10;
  
  System.out.println("sql:"+sql.toString());
  List rs=BbsDao.getBbsDao(sql.toString(), page, pageSize,cupage);//获取数据库信息
	System.out.println(rs.size());
	Bbs bbs=new Bbs();
	//将结果集表示成xml，由于是ajax技术没有做太多解释
	backInf.append("<bbss>");
	backInf.append("<indentity>"+indentity+"</indentity>");	
	Iterator it=rs.iterator();
	int totalpages=(Integer)it.next();
	backInf.append("<totalpages>"+totalpages+"</totalpages>");	
	int currentpage=(Integer)it.next();
	setCurrentPage(sess,currentpage);
	backInf.append("<currentpage>"+currentpage+"</currentpage>");
	int pagecounts=(Integer)it.next();
	backInf.append("<pagecounts>"+pagecounts+"</pagecounts>");
	
	System.out.println("totalpages:"+totalpages+"currentpage:"+currentpage+"pagecounts:"+pagecounts);
	while(it.hasNext()){
		bbs=(Bbs)it.next();
		backInf.append("<bbs>");
		backInf.append("<bbs_id>"+bbs.getBbs_id()+"</bbs_id>");			
	    backInf.append("<bbshot>"+bbs.getBbshot()+"</bbshot>");
	    backInf.append("<bbstopic>"+bbs.getBbstopic()+"</bbstopic>");
	    backInf.append("<bbscontent>"+bbs.getBbscontent()+"</bbscontent>");
	    backInf.append("<username>"+bbs.getUsername()+"</username>");
	    backInf.append("<bbsdata>"+bbs.getBbsdata()+"</bbsdata>");
	    backInf.append("<bbsrecount>"+bbs.getBbsrecount()+"</bbsrecount>");
	    backInf.append("<bbshits>"+bbs.getBbshits()+"</bbshits>");
	    backInf.append("<bbsrename>"+bbs.getBbsrename()+"</bbsrename>");
	    backInf.append("<board_id>"+bbs.getBoard_id()+"</board_id>");
	    backInf.append("<bbsredata>"+bbs.getBbsredata()+"</bbsredata>");
	    backInf.append("</bbs>");  
	    System.out.print("bbs.getBbs_id()"+bbs.getUsername());
	    
	}
	backInf.append("</bbss>");
    out.print(backInf.toString());
	out.flush();
	out.close();
    }

  public  void setCurrentPage(HttpSession sess,int currentPage){
	if(sess.getAttribute("currentPage")!=null){
		sess.removeAttribute("currentPage");
	}
	sess.setAttribute("currentPage", currentPage);
	System.out.print(currentPage+"设置当前页 ");
}
	public void init() throws ServletException {
		// Put your code here
	}

}