如何做bbs系统?

Question

结构上随便参考哪一个bbs
有用户登录，主题列表，发帖回复 。
可以在后台用一个数据库 
用bean来访问数据库
将结果集用jsp显示出来

Answer 1

第一步:建立一个数据库文件,最好建两个,一个放每条留言的数据,另一条放所有留言的树形目录,也就是XML文档;
第二步:建立你自己的类文件,存放树形目录的文档就是留言的关系树;
第三步:完成JSP页面.
我曾经写过的一个类文件代码,可以参考一下:
****************************************
public class ForumList {
    private LinkSQL ls=null;
    private ResultSet rs=null;
    private String viewXML=null;
    private String xsl=""; //XSL解析文件
    private Document document=null;
    private int total=0;    public int getTotal(){return this.total;}    /**
     * 设置XSL解析文档字串
     * @return String
     */
    public String getxsl(){
        this.xsl="<?xml version=\"1.0\" encoding=\"gb2312\"?>"
                    +"<xsl:stylesheet version=\"1.0\" xmlns:xsl=\"http://www.w3.org/1999/XSL/Transform\" >"
                    +"<xsl:output method=\"xml\" indent=\"yes\" encoding=\"gb2312\"/>"
                    +"<xsl:template match=\"/\">"
                    +"<table width=\"98%\">"
                    +"<xsl:for-each select=\"bbs//notes|bbs//renotes|bbs//notes//renotes\">"
                    +"<tr><td><a>"
                    +"<xsl:attribute name=\"href\">content.jsp?id=<xsl:value-of select=\"id\"/></xsl:attribute>"
                    +"<xsl:attribute name=\"target\">InfoFrame</xsl:attribute>"
                    +"<xsl:value-of select=\"title\"/>"
                    +"</a></td></tr>"
                    +"</xsl:for-each>"
                    +"</table>"
                    +"</xsl:template>"
                    +"</xsl:stylesheet>";
        return this.xsl;
    }    /**
     * 从数据库里提取信息
     * @return String
     */
    public String getList(){
        StringBuffer sb=new StringBuffer();
        sb.append("<?xml version=\"1.0\" encoding=\"gb2312\"?>");
        sb.append("<bbs>");
        ls=new LinkSQL();
        ls.setsql("select groupvalue from groupTable order by groupID desc");
        try{
            this.rs=ls.getResultSet();
            while(rs.next()){
                String s=rs.getString("groupvalue");
                sb.append(s);
            }
        }catch(IOException ioe){ioe.printStackTrace();}
        catch(ClassNotFoundException cnfe){cnfe.printStackTrace();}
        catch(SQLException se){se.printStackTrace();}
        finally{
            try{
                if(this.rs!=null) rs.close();
                this.ls.closeAll();
            }catch(Exception e){e.printStackTrace();}
        }
        sb.append("</bbs>");
        return sb.toString();
    }    /**
     * XML文档以HTML形式输出
     * @return String
     * @throws Exception
     */
    public String getHtmlList(int nowpage) throws Exception{
        String xml="";
        int pageNumber=0 ,countInfo=0 ,pageTotalNumber=0 ,perNumber=10;
        xml=this.getList(); //取得XML文档内容
        StringBuffer newxml=new StringBuffer();
        newxml.append("<?xml version=\"1.0\" encoding=\"gb2312\"?>");
        newxml.append("<bbs>");
        ////////////
        javax.xml.parsers.DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        org.xml.sax.InputSource is=new InputSource(new StringReader(xml));
        javax.xml.parsers.DocumentBuilder builder=factory.newDocumentBuilder();
        this.document=builder.parse(is);
        NodeList idlist=this.document.getElementsByTagName("id");
        NodeList titlelist=this.document.getElementsByTagName("title");
        countInfo=idlist.getLength();
        pageTotalNumber=countInfo/perNumber+1;
        this.total=pageTotalNumber;
        pageNumber=nowpage;
        if(pageNumber<1) pageNumber=1;
        if(pageNumber>pageTotalNumber) pageNumber=pageTotalNumber;
        for(int i=(pageNumber-1)*perNumber;i<pageNumber*perNumber;i++){
            if(i>=countInfo) break;
            else{
                newxml.append("<notes><id>"+idlist.item(i).getFirstChild().getNodeValue()+"</id>");
                newxml.append("<title>"+titlelist.item(i).getFirstChild().getNodeValue()+"</title></notes>");
            }
        }
        newxml.append("</bbs>");
        System.out.println(newxml);
        ///////////
        Transformer tf=TransformerFactory.newInstance().newTransformer(
                            new javax.xml.transform.stream.StreamSource(
                                new StringReader(this.getxsl())));
        ByteArrayOutputStream bos=new ByteArrayOutputStream();
        tf.transform(new StreamSource(new StringReader(newxml.toString()))
                    ,new StreamResult(bos)); //XSL解析XML文档并输出
        byte[] ba=bos.toByteArray();
        return new String(ba);
    }    public String updatedocument(){
        CharArrayWriter caw=new CharArrayWriter();//exporting the io into the EMS momory.
        TransformerFactory tfFactory =TransformerFactory.newInstance();
        try{
            Transformer transformer = tfFactory.newTransformer();
            DOMSource source=new DOMSource(this.document);
            StreamResult result=new StreamResult(caw);
            transformer.transform(source, result);
        }catch(TransformerConfigurationException tce){tce.printStackTrace();}
        catch(TransformerException tfe){tfe.printStackTrace();}
        char[] ba=caw.toCharArray();
        return new String(ba);//
    }    //test!!
    public static void main(String[] args) throws Exception{
        ForumList fl=new ForumList();
        fl.getHtmlList(3);
        System.out.println(fl.getTotal()+"");
    }
}