马士兵讲jsp项目--BBS项目分析笔记

1 导言

作为一个新手JAVA程序员，我相信很多人和我一样急切的想要寻找项目来做，这里我把马士兵老师讲的JAVA WEB的第一个小项目拿过来给大家分享一下。

首先，对一个项目而言我们先要认识清楚我们要做什么。这里我们要做的是一个模拟的小型BBS，内容分为以下几块：

1、树形展示回帖内容

2.、详细展示帖子内容

3、回复帖子功能

4、管理员登陆功能

5、删除功能

对这个项目而言，我们使用纯JSP最为联系语言，以后使用JSP+JAVABEAN这种主流的方法。纯JSP将事物与展示放在一起做，业务逻辑混乱，但是做一次来培养我们的业务逻辑思考，在这个过程中我们会体会到这种不足，之后自然而然的会投入到JAVABEAN+JSP的怀抱中。

2 数据库分析

作为一个BBS网站，我们主要做的是将数据库中的内容在网页上展示出来，所以我们需要一个良好的数据库作为我们的测试数据。

数据库如下：

create database bbs;

use bbs;

create table article 
(
id int primary key auto_increment,
pid int,
rootid int,
title varchar(255),
cont text,
pdate datetime,
isleaf int 
);

insert into article values (null, 0, 1, '蚂蚁大战大象', '蚂蚁大战大象', now(), 1);
insert into article values (null, 1, 1, '大象被打趴下了', '大象被打趴下了',now(), 1);
insert into article values (null, 2, 1, '蚂蚁也不好过','蚂蚁也不好过', now(), 0);
insert into article values (null, 2, 1, '瞎说', '瞎说', now(), 1);
insert into article values (null, 4, 1, '没有瞎说', '没有瞎说', now(), 0);
insert into article values (null, 1, 1, '怎么可能', '怎么可能', now(), 1);
insert into article values (null, 6, 1, '怎么没有可能', '怎么没有可能', now(), 0);
insert into article values (null, 6, 1, '可能性是很大的', '可能性是很大的', now(), 0);
insert into article values (null, 2, 1, '大象进医院了', '大象进医院了', now(), 1);
insert into article values (null, 9, 1, '护士是蚂蚁', '护士是蚂蚁', now(), 0);

对于BBS中每个帖子的内容，首先我们要有帖子id,他回复的是哪个楼pid，以及主题rootid，回复内容的“主题title+正文cont”，回复日期pdate,是否为叶子节点即是否没有人回复他。对于一个小型测试用数据库已经足够，业务逻辑正确就行，我们不考虑界面美观，毕竟这是我们的练手项目。

三 JSP代码

1 树形展示帖子主题

每个bbs都有一个入口界面，BBS入口界面基本上都是以树形展示为主，比如百度贴吧与天涯论坛。代码如下：

<%@ page language="java" contentType="text/html; charset=gbk"
    pageEncoding="gbk"%>
<%@ page import="java.sql.*" %>

<%//检查管理员session是否登陆，若登陆显示删除按钮
String admin = (String)session.getAttribute("admin");
if(admin != null && admin.equals("true")) {
    login = true;
}
%>

<%!
String str = "";//全局声明，保存需要打印的字符串，即显示内容
boolean login = false;//默认设为管理员未登录
private void tree(Connection conn, int id, int level) {
    Statement stmt = null;
    ResultSet rs = null;
    String preStr = "";
    for(int i=0; i<level; i++) {//层次化结构显示，level为传入参数
        preStr += "----";
    }
    try {
        stmt = conn.createStatement();
        String sql = "select * from article where pid = " + id;
        rs = stmt.executeQuery(sql);
        String strLogin = "";
        
        while(rs.next()) {//递归查询该节点下是否还有子节点，先打印自己节点，再打印子节点
            if(login) {
                strLogin = "<td><a href='Delete.jsp?id=" + rs.getInt("id") + "&pid=" + rs.getInt("pid") + "'>删除</a>";
            }//字符串用于控制是否显示删除按钮
            str += "<tr><td>" + rs.getInt("id") + "</td><td>" +
                   preStr + "<a href='ShowArticleDetail.jsp?id=" + rs.getInt("id") + "'>" + 
                   rs.getString("title") + "</a></td>" +
                   strLogin +
                   "</td></tr>";
            if(rs.getInt("isleaf") != 0) {//如果不是叶子节点，证明还存在子节点，递归打印
                tree(conn, rs.getInt("id"), level+1);
            }
        }
    } catch (SQLException e) {
        e.printStackTrace();
    } finally {
        try {
            if(rs != null) {
                rs.close();
                rs = null;
            }
            if(stmt != null) {
                stmt.close();
                stmt = null;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}
%>

<%
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost/bbs?user=root&password=123456";
Connection conn = DriverManager.getConnection(url);

Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from article where pid = 0");
String strLogin = "";
while(rs.next()) {
    if(login) {
        strLogin = "<td><a href='Delete.jsp?id=" + rs.getInt("id") + "&pid=" + rs.getInt("pid") + "'>删除</a>";
    }
    str += "<tr><td>" + rs.getInt("id") + "</td><td>" +
           "<a href='ShowArticleDetail.jsp?id=" + rs.getInt("id") + "'>" + 
           rs.getString("title") + "</a></td>" +
           strLogin +
           "</td></tr>";
       if(rs.getInt("isleaf") != 0) {
           tree(conn, rs.getInt("id"), 1);
       }
}
rs.close();
stmt.close();
conn.close();
%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gbk">
<title>Insert title here</title>
</head>
<body>
<a href="Post.jsp">发表新帖</a>
<table border="1">
<%= str %>
<% 
str = ""; //清空str，否则每刷新一次打印一次
login = false;//清空登录位
%>
</table>
</body>

</html>

2 详情页面

在上面的页面中我们加入了查看详情的链接，这里我们写详情链接

<%@ page language="java" contentType="text/html; charset=GB18030"
    pageEncoding="GB18030"%>
<%@ page import="java.sql.*" %>
<%
String strid = request.getParameter("id");//查看上个页面，我们需要查询的内容传来了id，这里第一步就是接受id
int id = Integer.parseInt(strid);//传来的参数默认为字符串，我们转换为int类型，便于sql查询
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/bbs?user=root&password=123456";
Connection conn = DriverManager.getConnection(url);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from article where id = "+ id);
    
 %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030">
<title>Insert title here</title>
</head>
<body>
<%
if(rs.next()){//查询只能拿到一条记录，这里用if就行，用table展示出来
%>
    <table border="1">
        <tr>
            <td>ID</td>
            <td><%= rs.getInt("id") %></td>
        </tr>
        <tr>
            <td>Title</td>
            <td><%= rs.getString("title") %></td>
        </tr>
                <tr>
            <td>Content</td>
            <td><%= rs.getString("cont") %></td>
        </tr>
    </table>

<%--加入回复链接，指向回复页面，需要传入参数为，回复楼的id,以及帖子id,这里rootid不是必要参数，加上可以简化流程 --%>
 <a href="Reply.jsp?id=<%= rs.getInt("id")%>&rootid=<%= rs.getString("rootid")%>">回复</a>
 <%    
}//记得打开的东西要逆序关闭
rs.close();
stmt.close();
conn.close();
 %>
</body>
</html>

3 回复页面

<%@ page language="java" contentType="text/html; charset=gbk"
    pageEncoding="gbk"%>


<%//任何情况下都是先接受传递过来的参数
int id = Integer.parseInt(request.getParameter("id"));
int rootId = Integer.parseInt(request.getParameter("rootid"));
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gbk">
<title>Insert title here</title>

<script language="javascript">
<!--    
    //javascript去空格函数 
    function LTrim(str){ //去掉字符串 的头空格
        var i;
        for(i=0;i<str.length; i++) {
            if(str.charAt(i)!=" ") break;
        }
        str = str.substring(i,str.length);
        return str;
    }
    
    function RTrim(str){
        var i;
        for(i=str.length-1;i>=0;i--){
            if(str.charAt(i)!=" "&&str.charAt(i)!=" ") break;
        }
        str = str.substring(0,i+1);
        return str;
    }
    function Trim(str){
    
        return LTrim(RTrim(str));
    
    }
    
    function check() {
        if(Trim(document.reply.title.value) == "") {
            alert("please intput the title!");
            document.reply.title.focus();
            return false;
        }
        
        if(Trim(document.reply.cont.value) == "") {
            alert("plsease input the content!");
            document.reply.cont.focus();
            return false;
        }
        
        return true;
        
    }
-->
</script>

</head>
<body>
<form name=reply action="ReplyOK.jsp" method="post" onsubmit="return check()">
    <input type="hidden" name="id" value="<%=id %>">
    <input type="hidden" name="rootid" value="<%= rootId %>">
    <table border="1">
        <tr>
            <td>
                <input type="text" name="title" size="80">
            </td>
        </tr>
        <tr>
            <td>
                <textarea cols="80" rows="12" name="cont"></textarea>
            </td>
        </tr>
        <tr>
            <td>
                <input type="submit" value="提交">
            </td>
        </tr>
    </table>
</form>
</body>
</html>

4 回复成功，调转显示

任何帖子回复成功后都要进行跳转，否则用户需要手动点击，太不人性化

<%@ page language="java" contentType="text/html; charset=GB18030"
    pageEncoding="GB18030"%>
<%@ page import="java.sql.*" %>
<%
request.setCharacterEncoding("gbk");//request采用默认编码，我们给他转换成中文编码
int id = Integer.parseInt(request.getParameter("id"));//第一步，接受传递过来的参数
int rootid = Integer.parseInt(request.getParameter("rootid"));
String title = request.getParameter("title");
String cont = request.getParameter("cont");

if(title == null) {//虽然前台检查过了，后台仍然要检查
    out.println("error! please use my bbs in the right way!");
    return;
}

title = title.trim();

if(title.equals("")) {
    out.println("title could not be empty!");
    return;
}

cont = cont.trim();

if(cont.equals("")) {
    out.println("content could not be empty!");
    return;
}

cont = cont.replaceAll("\n", "<br>");//将用户输入域得到的字符串中的回车用html中的换行符替换
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/bbs?user=root&password=123456";
Connection conn = DriverManager.getConnection(url);
conn.setAutoCommit(false);//我们回复过的楼层必然不再是叶子节点，因此这里要用事物处理，关闭自动提交
String sql = "insert into article values(null,?,?,?,?,now(),0)";
PreparedStatement pstmt = conn.prepareStatement(sql);//sql语句过于负责，我们用PreparedStatement进行简便操作
Statement stmt = conn.createStatement();

pstmt.setInt(1,id);
pstmt.setInt(2,rootid);
pstmt.setString(3, title);
pstmt.setString(4, cont);
pstmt.executeUpdate();

stmt.executeUpdate("update article set isleaf = 1 where id = "+id);

conn.commit();
conn.setAutoCommit(true);//回复自动提交功能

stmt.close();
pstmt.close();
conn.close();
 %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030">
<title>Insert title here</title>
</head>
<body>
<%
response.sendRedirect("ShowArticleTree.jsp");//重定向到入口界面
 %>
</body>
</html>

5 发表新帖

<%@ page language="java" contentType="text/html; charset=gbk"
    pageEncoding="gbk"%>
<%@ page import="java.sql.*" %>

<%

request.setCharacterEncoding("gbk");
String action = request.getParameter("action");//接受传递给自己的参数
if(action != null && action.equals("post")) {
	String title = request.getParameter("title");
	String cont = request.getParameter("cont");
	
	cont = cont.replaceAll("\n" , "<br>");//将回车符换为html重的换行符
	
	Class.forName("com.mysql.jdbc.Driver");
	String url = "jdbc:mysql://localhost/bbs?user=root&password=123456";
	Connection conn = DriverManager.getConnection(url);
	
	conn.setAutoCommit(false);
	
	String sql = "insert into article values (null, 0, ?, ?, ?, now(), 0)";
	PreparedStatement pstmt = conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);
	Statement stmt = conn.createStatement();
	
	pstmt.setInt(1, -1);
	pstmt.setString(2, title);
	pstmt.setString(3, cont);
	pstmt.executeUpdate();
	
	ResultSet rsKey = pstmt.getGeneratedKeys();
	rsKey.next();
	int key = rsKey.getInt(1);
	rsKey.close();
	stmt.executeUpdate("update article set rootid = " + key + " where id = " + key);
	
	conn.commit();
	conn.setAutoCommit(true);
	
	stmt.close();
	pstmt.close();
	conn.close();
	
	response.sendRedirect("ShowArticleFlat.jsp");//重定向到平面显示
}
%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gbk">
<title>Insert title here</title>
</head>
<body>
<form action="Post.jsp" method="post">
	<input type="hidden" name="action" value="post">
	<table border="1">
		<tr>
			<td>
				<input type="text" name="title" size="80">
			</td>
		</tr>
		<tr>
			<td>
				<textarea cols="80" rows="12" name="cont"></textarea>
			</td>
		</tr>
		<tr>
			<td>
				<input type="submit" value="提交">
			</td>
		</tr>
	</table>
</form>
</body>
</html>

6 删除功能

<%@ page language="java" contentType="text/html; charset=GB18030"
    pageEncoding="GB18030"%>
<%@ page import="java.sql.*" %>
<%!//递归判断该id下面是否有子结点，有的话递归，最后删除自己
private void del(Connection conn,int id){
	Statement stmt = null;
	ResultSet rs = null;
	try{
		stmt = conn.createStatement();
		String sql = "select * from article where pid = "+ id;//查询该id下的所有内容，因此该id应作为pid查询
		rs = stmt.executeQuery(sql);
		while(rs.next()){//查询到的结果集进行一条一条循环迭代
			del(conn,rs.getInt("id"));
		}
		stmt.executeUpdate("delete from article where id = " + id);
	} catch(SQLException e){
		e.printStackTrace();
	} finally{
		try{
			if(rs != null){//注意异常的捕获，这样处理更加严谨
				rs.close();
				rs = null;
			}
			if(stmt != null){
				stmt.close();
				stmt = null;
			}
		
		} catch(SQLException e){
			e.printStackTrace();
		}
	}
}
 %>
 <%
String admin = (String)session.getAttribute("admin");
if(admin == null || !admin.equals("true")) {
	out.println("孙贼，别想找BUG来删除！");
	return;
}
  %>
<%
int id = Integer.parseInt(request.getParameter("id"));//第一步，接受传递过来的参数
int pid = Integer.parseInt(request.getParameter("pid"));//第一步，接受传递过来的参数
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/bbs?user=root&password=123456";
Connection conn = DriverManager.getConnection(url);
conn.setAutoCommit(false);//我们回复过的楼层必然不再是叶子节点，因此这里要用事物处理，关闭自动提交
del(conn,id);

Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select count(*) from article where pid = " + pid);
rs.next();
int count = rs.getInt(1);
rs.close();
stmt.close();
if (count <= 0){
	Statement stmtUpdate = conn.createStatement();
	stmtUpdate.executeUpdate("update article set isleaf = 0 where id = " + pid);
	stmtUpdate.close();
}
conn.commit();
conn.setAutoCommit(true);//回复自动提交功能
conn.close();
 %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030">
<title>Insert title here</title>
</head>
<body>
<%
response.sendRedirect("ShowArticleTree.jsp");//重定向到入口界面
 %>
</body>
</html>

7 登陆页面

登陆页面主要有美工来做，这里的代码主要看业务逻辑

<%@ page contentType="text/html; charset=gbk" pageEncoding="gbk" %>

<%
String action = request.getParameter("action");
if(action != null && action.equals("login")) {
	String username = request.getParameter("uname");
	String password = request.getParameter("pwd");
	if(username == null || !username.equals("admin")) {
		%>
		<font color="white" size=5>username not correct!</font>
		<%
		//return;
	}else if(password == null || !password.equals("admin")) {
		out.println("password not correct!");
		//return;
	}else {
		session.setAttribute("admin", "true");
		response.sendRedirect("ShowArticleTree.jsp");
	}
}
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!-- saved from url=(0054)http://www.simworld.com/client_access/client_login.asp -->
<HTML><HEAD><TITLE>SIM - Client Access - Login</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gbk" pageEncoding="gbk"><LINK 
href="images/sim_stylesheet.css" type=text/css 
rel=styleSheet>
<SCRIPT language=JavaScript src="" type=text/javascript></SCRIPT>

<SCRIPT language=JavaScript src="" type=text/javascript></SCRIPT>

<SCRIPT language=JavaScript src="" type=text/javascript></SCRIPT>

<META content="MSHTML 6.00.2900.2963" name=GENERATOR>
<style type="text/css">
<!--
.STYLE1 {color: #CCCCCC}
-->
</style>

</HEAD>
<BODY bgColor=#20355a leftMargin=0 topMargin=0 onload=init() marginheight="0" 
marginwidth="0"><!--Begin all TOP NAVIGATIOND ROPDOWN LAYERS ------------><!--Begin About Sim Dropdown 1 -->
<DIV id=about_sim_drop1>
<TABLE cellSpacing=0 cellPadding=0 width=140 border=0>
  <TBODY>
  <TR>
    <TD bgColor=#ffffff>
      <TABLE cellSpacing=2 cellPadding=2 width=140 border=0>
        <TBODY>
        <TR>
          <TD vAlign=top align=left width=130><A class=topnav 
            onmouseover="stopTime(); showLayer('about_sim_corporate_drop2'); hideLayer('about_sim_portfolio_drop2');" 
            onmouseout=startTime(); 
            href="http://www.simworld.com/about_sim/corporate/index.asp">Corporate 
            Info</A></TD>
          <TD vAlign=top width=10><IMG height=10 alt=arrow 
            src="images/nav_arrows.gif" 
        width=10></TD></TR></TBODY></TABLE></TD></TR><!-- 
	<tr> 
       <td bgcolor="#CACFDA"> 
         <table width="140" border="0" cellspacing="2" cellpadding="2">
           <tr> 
             <td width="130" valign="top" align="left"><a href="/about_sim/services/index.asp" onMouseOver="stopTime(); hideLayer('about_sim_corporate_drop2');" onMouseOut="startTime();" class="topnav">Services</a></td>
             <td width="10" valign="top"><img src="/pics/spacer.gif" alt="" width="10" height="10"></td>
           </tr>
         </table>
       </td>
     </tr>
-->
  <TR>
    <TD bgColor=#cacfda>
      <TABLE cellSpacing=2 cellPadding=2 width=140 border=0>
        <TBODY>
        <TR>
          <TD vAlign=top align=left width=130><A class=topnav 
            onmouseover="stopTime(); hideLayer('about_sim_corporate_drop2');" 
            onmouseout=startTime(); 
            href="http://www.simworld.com/about_sim/products/index.asp">Products</A></TD>
          <TD vAlign=top width=10><IMG height=10 alt="" 
            src="images/spacer.gif" 
        width=10></TD></TR></TBODY></TABLE></TD></TR><!--<tr> 
       <td bgcolor="#CACFDA"> 
         <table width="140" border="0" cellspacing="2" cellpadding="2">
           <tr> 
             <td width="130" valign="top" align="left"><a href="/about_sim/portfolio/index1.asp" onMouseOver="stopTime(); showLayer('about_sim_portfolio_drop2'); hideLayer('about_sim_corporate_drop2');" onMouseOut="startTime();" class="topnav">Portfolio</a></td>
             <td width="10" valign="top"><img src="/pics/nav_arrows.gif" alt="arrow" width="10" height="10"></td>
           </tr>
         </table>
       </td>
     </tr>-->
  <TR>
    <TD bgColor=#ffffff>
      <TABLE cellSpacing=2 cellPadding=2 width=140 border=0>
        <TBODY>
        <TR>
          <TD vAlign=top align=left width=130><A class=topnav 
            onmouseover=stopTime(); 
            onmouseout="startTime(); hideLayer('about_sim_corporate_drop2');" 
            href="http://www.simworld.com/about_sim/portfolio/index_temp.asp">Portfolio</A></TD>
          <TD vAlign=top width=10><IMG height=10 alt=arrow 
            src="images/spacer.gif" 
        width=10></TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE></DIV><!-- End About Sim Dropdown 1 --><!--Begin About Sim Corporate Dropdown 2 -->
<DIV id=about_sim_corporate_drop2>
<TABLE cellSpacing=0 cellPadding=0 width="100%" border=0>
  <TBODY>
  <TR>
    <TD bgColor=#cacfda>
      <TABLE cellSpacing=2 cellPadding=2 width="100%" border=0>
        <TBODY>
        <TR>
          <TD vAlign=top align=left width="100%"><A class=topnav 
            onmouseover=stopTime(); onmouseout=startTime(); 
            href="http://www.simworld.com/about_sim/corporate/mission.asp">Mission</A></TD></TR></TBODY></TABLE></TD></TR>
  <TR>
    <TD bgColor=#ffffff>
      <TABLE cellSpacing=2 cellPadding=2 width="100%" border=0>
        <TBODY>
        <TR>
          <TD vAlign=top align=left width="100%"><A class=topnav 
            onmouseover=stopTime(); onmouseout=startTime(); 
            href="http://www.simworld.com/about_sim/corporate/philosophy.asp">Philosophy</A></TD></TR></TBODY></TABLE></TD></TR>
  <TR>
    <TD bgColor=#cacfda>
      <TABLE cellSpacing=2 cellPadding=2 width="100%" border=0>
        <TBODY>
        <TR>
          <TD vAlign=top align=left width="100%"><A class=topnav 
            onmouseover=stopTime(); onmouseout=startTime(); 
            href="http://www.simworld.com/about_sim/corporate/team.asp">Team</A></TD></TR></TBODY></TABLE></TD></TR>
  <TR>
    <TD bgColor=#ffffff>
      <TABLE cellSpacing=2 cellPadding=2 width="100%" border=0>
        <TBODY>
        <TR>
          <TD vAlign=top align=left width="100%"><A class=topnav 
            onmouseover=stopTime(); onmouseout=startTime(); 
            href="http://www.simworld.com/about_sim/corporate/specialty.asp">Specialty 
            Markets </A></TD></TR></TBODY></TABLE></TD></TR>
  <TR>
    <TD bgColor=#cacfda>
      <TABLE cellSpacing=2 cellPadding=2 width="100%" border=0>
        <TBODY>
        <TR>
          <TD vAlign=top align=left width="100%"><A class=topnav 
            onmouseover=stopTime(); onmouseout=startTime(); 
            href="http://www.simworld.com/about_sim/corporate/news.asp">News 
            & Awards</A></TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE></DIV><!--Begin About Sim Corporate Dropdown 2 --><!--Begin About Sim Portfolio Dropdown 2 -->
<DIV id=about_sim_portfolio_drop2><!--<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr> 
    <td bgcolor="#CACFDA"> 
      <table width="100%" border="0" cellspacing="2" cellpadding="2">
        <tr> 
            <td width="100%" valign="top" align="left"><a href="/about_sim/portfolio/websites.asp" onMouseOver="stopTime();" onMouseOut="startTime();" class="topnav">Websites</a></td>
        </tr>
      </table>
    </td>
  </tr>
  <tr> 
    <td bgcolor="#FFFFFF"> 
      <table width="100%" border="0" cellspacing="2" cellpadding="2">
        <tr> 
            <td width="100%" valign="top" align="left"><a href="/about_sim/portfolio/multimedia.asp" onMouseOver="stopTime();" onMouseOut="startTime();" class="topnav">Multimedia Presentations</a></td>
        </tr>
      </table>
    </td>
  </tr>
  <tr> 
    <td bgcolor="#CACFDA"> 
      <table width="100%" border="0" cellspacing="2" cellpadding="2">
        <tr> 
            <td width="100%" valign="top" align="left"><a href="/about_sim/portfolio/print_graphic_design.asp" onMouseOver="stopTime();" onMouseOut="startTime();" class="topnav" target="_blank">Print / Graphic Design</a></td>
        </tr>
      </table>
    </td>
  </tr>
  <tr> 
    <td bgcolor="#FFFFFF"> 
      <table width="100%" border="0" cellspacing="2" cellpadding="2">
        <tr> 
            <td width="100%" valign="top" align="left"><a href="/about_sim/client_list.pdf" onMouseOver="stopTime();" onMouseOut="startTime();" class="topnav" target=_"blank">Client List (PDF)</a></td>
        </tr>
      </table>
    </td>
  </tr>
</table>--></DIV><!--Begin About Sim Portfolio Dropdown 2 --><!--Begin Client Access Dropdown 1 -->
<DIV id=client_access_drop1><!--<table width="140" border="0" cellspacing="0" cellpadding="0">
     <tr> 
       <td bgcolor="#FFFFFF"> 
         <table width="140" border="0" cellspacing="2" cellpadding="2">
           <tr> 
             <td width="130" valign="top" align="left"><a href="/client_access/client_login.asp" onMouseOver="stopTime(); hideLayer('client_access_customer_drop2');" onMouseOut="startTime();" class="topnav">Client Login</a></td>
             <td width="10" valign="top"><img src="/pics/spacer.gif" alt="" width="10" height="10"></td>
           </tr>
         </table>
       </td>
     </tr>
     <tr> 
       <td bgcolor="#CACFDA"> 
         <table width="140" border="0" cellspacing="2" cellpadding="2">
           <tr> 
             <td width="130" valign="top" align="left"><a href="/client_access/customerservice/index1.asp" onMouseOver="stopTime(); showLayer('client_access_customer_drop2');" onMouseOut="startTime();" class="topnav">Customer Service</a></td>
             <td width="10" valign="top"><img src="/pics/nav_arrows.gif" alt="arrow" width="10" height="10"></td>
           </tr>
         </table>
       </td>
     </tr>
     <tr> 
       <td bgcolor="#FFFFFF"> 
         <table width="140" border="0" cellspacing="2" cellpadding="2">
           <tr> 
             <td width="130" valign="top" align="left"><a href="/under_construction.asp" onMouseOver="stopTime(); hideLayer('client_access_customer_drop2');" onMouseOut="startTime();" class="topnav">Beyond Today</a></td>
             <td width="10" valign="top"><img src="/pics/spacer.gif" alt="" width="10" height="10"></td>
           </tr>
         </table>
       </td>
     </tr>
   </table>--></DIV><!-- End Client Access Dropdown 1 --><!--Begin Client Access Customer Service Dropdown 2 -->
<DIV id=client_access_customer_drop2><!--<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr> 
    <td bgcolor="#CACFDA"> 
      <table width="100%" border="0" cellspacing="2" cellpadding="2">
        <tr> 
            <td width="100%" valign="top" align="left"><a href="/client_access/customerservice/policy1.asp" onMouseOver="stopTime();" onMouseOut="startTime();" class="topnav">Our Policy</a></td>
        </tr>
      </table>
    </td>
  </tr>
  <tr> 
    <td bgcolor="#FFFFFF"> 
      <table width="100%" border="0" cellspacing="2" cellpadding="2">
        <tr> 
            <td width="100%" valign="top" align="left"><a href="/client_access/customerservice/help1.asp" onMouseOver="stopTime();" onMouseOut="startTime();" class="topnav">Help</a></td>
        </tr>
      </table>
    </td>
  </tr>
  <tr> 
    <td bgcolor="#CACFDA"> 
      <table width="100%" border="0" cellspacing="2" cellpadding="2">
        <tr> 
            <td width="100%" valign="top" align="left"><a href="/client_access/customerservice/downloads1.asp" onMouseOver="stopTime();" onMouseOut="startTime();" class="topnav">Downloads</a></td>
        </tr>
      </table>
    </td>
  </tr>
  <tr> 
    <td bgcolor="#FFFFFF"> 
      <table width="100%" border="0" cellspacing="2" cellpadding="2">
        <tr> 
            <td width="100%" valign="top" align="left"><a href="/client_access/customerservice/tech_standards1.asp" onMouseOver="stopTime();" onMouseOut="startTime();" class="topnav" target=_"blank">Technical Standards</a></td>
        </tr>
      </table>
    </td>
  </tr>
</table>--></DIV><!-- End Client Access Customer Service Dropdown 2 --><!--Begin Join our Team Dropdown 1 -->
<DIV id=join_our_team_drop1>
<TABLE cellSpacing=0 cellPadding=0 width=150 border=0>
  <TBODY>
  <TR>
    <TD bgColor=#ffffff>
      <TABLE cellSpacing=2 cellPadding=2 width=150 border=0>
        <TBODY>
        <TR>
          <TD vAlign=top width=10><IMG height=10 alt="" 
            src="images/client_access.htm" 
          width=10></TD>
          <TD vAlign=top align=right width=140><A class=topnav 
            onmouseover=stopTime(); onmouseout=startTime(); 
            href="http://www.simworld.com/join_our_team/job_openings.asp">Job 
            Openings</A></TD></TR></TBODY></TABLE></TD></TR>
  <TR>
    <TD bgColor=#cacfda>
      <TABLE cellSpacing=2 cellPadding=2 width=150 border=0>
        <TBODY>
        <TR>
          <TD vAlign=top width=10><IMG height=10 alt="" 
            src="images/spacer.gif" width=10></TD>
          <TD vAlign=top align=right width=140><A class=topnav 
            onmouseover=stopTime(); onmouseout=startTime(); 
            href="http://www.simworld.com/join_our_team/apply_online.asp">Employee 
            Benefits</A></TD></TR></TBODY></TABLE></TD></TR>
  <TR>
    <TD bgColor=#ffffff>
      <TABLE cellSpacing=2 cellPadding=2 width=150 border=0>
        <TBODY>
        <TR>
          <TD vAlign=top width=10><IMG height=10 alt="" 
            src="images/spacer.gif" width=10></TD>
          <TD vAlign=top align=right width=140><A class=topnav 
            onmouseover=stopTime(); onmouseout=startTime(); 
            href="http://www.simworld.com/join_our_team/corp_culture.asp">Corporate 
            Culture</A></TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE></DIV><!-- End Join Our Team  Dropdown 1 --><!--End all TOP NAVIGATIOND ROPDOWN LAYERS ------------><!--Begin Browser Spanning Table, this allows Main Web Site Table to be centered in the middle of the browser -->
<TABLE height="100%" cellSpacing=0 cellPadding=0 width="100%" align=center 
border=0>
  <TBODY>
  <TR>
    <TD><!--Begin Main Web Site Table All Website Design elements below-->
      <TABLE borderColor=#ffffff cellSpacing=0 cellPadding=0 width=760 
      align=center border=1>
        <TBODY>
        <TR>
          <TD>
            <TABLE cellSpacing=0 cellPadding=0 width="100%" border=0>
              <TBODY>
              <TR>
                <TD><!-- Begin Top Logo, Navigation and Message bar Table -->
                  <TABLE cellSpacing=0 cellPadding=0 width="100%" border=0><!--Beign Global Nav Buttons --->
                    <TBODY>
                    <TR>
                      <TD rowSpan=2><IMG height=53 
                        alt="Screened Images Multimedia" 
                        src="images/sim_logo_top.gif" 
                        width=136 useMap=#top_logo_map border=0><MAP 
                        name=top_logo_map><AREA shape=RECT 
                          alt="Screened Images Multimedia [Back to Home]" 
                          coords=11,4,120,54 
                          href="http://www.simworld.com/index.asp"></MAP></TD>
                      <TD><span class="STYLE1">欢迎来到
                        著名的BBS后台</span></TD>
                    </TR>
                    <TR><!--End Global Nav Buttons --->
                      <TD><span class="STYLE1">不输入用户名密码不许进 用户名: admin 密码: admin </span></TD>
                    </TR></TBODY></TABLE><!-- End Top Logo, Navigation and Message bar Table --></TD></TR>
              <TR>
                <TD><!-- Begin Inner Content Table:  This portion will be customizable throughout the website -->
                  <TABLE cellSpacing=0 cellPadding=0 width="100%" border=0>
                    <TBODY>
                    <TR>
                      <TD><IMG height=324 alt="" 
                        src="images/client_login_left_arc.gif" 
                        width=137 useMap=#bot_logo_map border=0><MAP 
                        name=bot_logo_map><AREA shape=RECT 
                          alt="Screened Images Multimedia [Back to Home]" 
                          coords=11,0,120,24 
                          href="http://www.simworld.com/index.asp"></MAP></TD>
                      <TD>
                        <TABLE cellSpacing=0 cellPadding=0 width="100%" 
border=0>
                          <TBODY>
                          <TR>
                            <TD><IMG height=91 alt="CLIENT LOG-IN" 
                              src="images/client_login_title.gif" 
                              width=282></TD></TR>
                          <TR>
                            <TD>
                              <FORM action=Login.jsp method=post>
                              <input type=hidden name=action value=login>
                              <TABLE cellSpacing=0 cellPadding=0 width="100%" 
                              background="images/client_login_text_bg.gif" 
                              border=0>
                                <TBODY>
                                <TR>
                                <TD rowSpan=4><IMG height=158 alt="" 
                                src="images/spacer.gif" 
                                width=22 border=0></TD>
                                <TD colSpan=2>
                                <P class=bodydarkblue>Please enter your username 
                                and password here to preview your designs, check 
                                project status and/or submit new job 
                                requests.</P></TD></TR>
                                <TR>
                                <TD>
                                <P class=bodyldarkblue><LABEL 
                                for=uname>用户名:</LABEL></P></TD>
                                <TD><INPUT id=uname name=uname></TD></TR>
                                <TR>
                                <TD>
                                <P class=bodyldarkblue><LABEL 
                                for=pwd>密码:</LABEL></P></TD>
                                <TD><INPUT id=pwd type=password 
                                name=pwd></TD></TR>
                                <TR>
                                <TD vAlign=top colSpan=2><A class=bodydarkblue 
                                href="http://www.simworld.com/client_access/client_login.asp"><STRONG><!--Forget your password?--></STRONG></A><IMG 
                                height=1 alt="" 
                                src="images/spacer.gif" 
                                width=132 
                                border=0>     <INPUT 
                                type=image alt=Submit 
                                src="images/client_login_submit.gif" 
                                align=absMiddle value=Submit 
                                name=Submit></TD></TR></TBODY></TABLE></TD></TR>
                          <TR>
                            <TD><IMG height=75 alt="" 
                              src="images/client_login_bot_arc.gif" 
                              width=282></TD></TR></TBODY></TABLE></TD>
                      <TD><IMG height=324 alt="Log-in Image" 
                        src="images/client_login_main_pic.jpg" 
                        width=341></TD></TR></TBODY></TABLE><!-- End Inner Content Table --------></TD></TR>
              <TR>
                <TD><!-- Begin Bottom Navigation: Contact Us, Request A- Quote -->
                  <TABLE cellSpacing=0 cellPadding=0 width="100%" border=0>
                    <TBODY>
                    <TR>
                      <TD><A 
                        onmouseover="Rollover('nav_homepage_a','nav_homepage');" 
                        onmouseout="Rollover('nav_homepage','nav_homepage');" 
                        href="http://www.simworld.com/index.asp"></A><IMG height=26 
                        alt="" 
                        src="images/interior_bot_nav_bar.gif" 
                        width=100%></TD>
                    </TR>
                    <TR>
                      <TD><IMG height=12 
                        alt="Copyright 2003 Screened Images, Inc." 
                        src="images/bot_footer_bar.gif" 
                        width=760></TD></TR></TBODY></TABLE><!-- End Bottom Navigation: Contact Us, Request A- Quote --></TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE><!--End Main Web Site Table --></TD></TR></TBODY></TABLE><!--End Browser Spanning Table --></BODY></HTML>

8 平面展示

<%@ page language="java" contentType="text/html; charset=gbk"
	pageEncoding="gbk"%>
<%@ page import="java.sql.*"%>


<%
	int pageSize = 3;//定义一页显示多少条数据

	String strPageNo = request.getParameter("pageNo");//接受当前页数
	int pageNo;
	if (strPageNo == null || strPageNo.equals("")) {
		pageNo = 1;//若没有则默认第一页
	} else {
		try {
			pageNo = Integer.parseInt(strPageNo.trim());
		} catch (NumberFormatException e) {
			pageNo = 1;
		}
		if (pageNo <= 0)//不合法页默认第一页
			pageNo = 1;
	}

	Class.forName("com.mysql.jdbc.Driver");
	String url = "jdbc:mysql://localhost/bbs?user=root&password=123456";
	Connection conn = DriverManager.getConnection(url);

	Statement stmtCount = conn.createStatement();
	ResultSet rsCount = stmtCount
			.executeQuery("select count(*) from article where pid = 0");//拿出父亲节点为0的，即主题帖
	rsCount.next();
	int totalRecords = rsCount.getInt(1);

	int totalPages = totalRecords % pageSize == 0 ? totalRecords
			/ pageSize : totalRecords / pageSize + 1;//若可以整除则显示多少页，否则+1页
	if (pageNo > totalPages)
		pageNo = totalPages;//指定最多页数不可溢出

	int startPos = (pageNo - 1) * pageSize;//确定mysql中要取出来的数据位置

	Statement stmt = conn.createStatement();
	ResultSet rs = stmt
			.executeQuery("select * from article where pid = 0 order by pdate desc limit "
			+ startPos + "," + pageSize);//利用mysql中的分页来显示
%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gbk">
<title>Insert title here</title>
</head>
<body>
<a href="Post.jsp">发表新帖</a>

<table border="1">

	<%
	while (rs.next()) {
	%>
	<tr>
		<td><%=rs.getString("title")%></td>
	</tr>
	<%
	}
	rs.close();
	stmt.close();
	conn.close();
	%>
</table>

共<%=totalPages%>页 第<%=pageNo%>页
<a href="ShowArticleFlat.jsp?pageNo=<%=pageNo-1%>"> < </a>   <%--传递给本页要显示的页数 --%>
    
<a href="ShowArticleFlat.jsp?pageNo=<%=pageNo+1%>"> > </a>

<form name="form1" action="ShowArticleFlat.jsp"><%--动态提交数据--%>
	<select name="pageNo" onchange="document.form1.submit()">
		<%
		for(int i=1; i<=totalPages; i++) {
		%>
		<option value=<%=i%> <%=(pageNo == i) ? "selected" : ""%>> 第<%=i%>页
		<%
		}
		%>
	</select>
</form>

<form name="fom2" action="ShowArticleFlat.jsp">
	<input type=text size=4 name="pageNo" value=<%=pageNo%> />
	<input type="submit" value="go" />
</form>

</body>

</html>

3 总结

到此为止，一个纯JSP的BBS完成，大家应该感觉到了头绪有点乱的感觉，正是由于这种感觉，我们之后会采取jsp+javabean的方法来开发，那样代码逻辑性看上去会强很多。

给大家一个建议：这些代码都是先写出来功能模块，能够独立运行以后才慢慢加入其他控制模块以及健壮性模块，所以按照这个顺序写还是没那么困难的，希望大家都能够学好JAVA WEB！