一个完整的新闻发布系统

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一个完整的新闻发布系统

关键字:JSP、Java、新闻发布
环境:Tomcat 5.5.7 + J2SE 5.0 + PostgreSQL 8.0

我将分几个步骤完成对一个新闻发布系统的构建,来理解JSP的一些基本使用方法!

首先我将先介绍这个新闻发布系统的基本结构:

index.jsp:管理员登陆界面
check.jsp:验证管理员身份
main.jsp:管理员添加新闻的页面
pub.jsp:发布信息的页面
display:显示所有的新闻

而后台的程序主要有:

DB.java:数据库连接
MD5.java:MD5算法
PubBean.java:发布
CheckBean.java:核实登陆身份

即当你从index -> main -> display 走一趟你基本就可以完成一个新闻发布系统的基本功能了!

我并非把新闻的标题和内容都写入数据库,因为那样太耗费数据库系统的资源,而且在访问的时候总要读取数

据库,很费劲,我把新闻写入了一个单独的HTM文件,之后把标题及HTM文件的名字写入的数据库!

而这个HTM文件的名字怎么随机生成呢?我选择了MD5算法,因为每个新闻的标题都不会相同,所以保证了唯一

性!

下面我先把这个系统的基本框架勾勒出来,说的大一点,这似乎就是这个“系统”的“内核”啦!:)

================数据库部分==================

CREATE TABLE administrator
(
  admin char(16),
  "password" char(32)
)
WITHOUT OIDS;
ALTER TABLE administrator OWNER TO admin;

CREATE TABLE news
(
  title char(255),
  page char(255)
)
WITHOUT OIDS;
ALTER TABLE news OWNER TO admin;

================程序部分==================

package login;

import java.sql.*;

public class DB {

 private Connection conn;
 private Statement stmt;
 private ResultSet rs;
 
 public DB() {
  try {
   Class.forName("org.postgresql.Driver");
   conn = DriverManager.getConnection

("jdbc:postgresql://localhost:5432/news?user=admin&&password=");
   stmt = conn.createStatement();   
  }
  catch(Exception e) {
   System.out.println(e);
  }
 }
 
 public void update(String sql) {
  try {
   stmt.executeUpdate(sql);
  }
  catch(Exception e) {
   System.out.println(e);
  }
 }
 
 public ResultSet quarry(String sql) {
  try {
   rs = stmt.executeQuery(sql);
  }
  catch(Exception e) {
   System.out.println(e);
  }
  return rs;
 }
 
}

package login;

import java.sql.*;
import java.io.*;

public class PubBean {
 
 private String title,context;
 private DB db;
 private MD5 md5;
 
 public PubBean() {
  db = new DB();
  md5 = new MD5();  
 }
 
 public void setTitle(String title){
  this.title = title;
 }
 
 public void setContext(String context) {
  this.context = context;
 }

 public void pubIt() {
  try {
   title = new String(title.getBytes("8859_1"),"gb2312");
   context = new String(context.getBytes("8859_1"),"gb2312");
   String titleMD5 = md5.getkeyBeanofStr(title);
   db.update("insert into news values('"+title+"','"+titleMD5+"')");
   String file = "news\\ice"+titleMD5+".htm";
   PrintWriter pw = new PrintWriter(new FileOutputStream(file));
   pw.println("<title>"+title+"</title>");
   pw.println(context);
   pw.close(); 
  }
  catch(Exception e){
   System.out.println(e);
  }
 }
 
}

package login;

import java.sql.*;

public class CheckBean {
 
 private String message="",admin,password;
 private DB db;
 
 public CheckBean() {
  db = new DB(); 
 }
 
 public void setAdmin(String admin){
  this.admin = admin;
 }
 
 public void setPassword(String password) {
  this.password = password;
 }
 
 public String checkIt() {
  try {
   ResultSet rs = db.quarry("select * from administrator where

admin='"+this.admin+"'");
   while(rs.next()){
    String pws = rs.getString("password").trim();
    if(pws.equals(this.password)){
     message = "密码正确!"; 
    }
    else message = "密码错误!";
    return message;
   }
   message = "用户不存在!";
  }
  catch(Exception e) {
   System.out.println(e);
  }
  return message;
 }
 
}

================页面部分==================

index.jsp:

<% page contentType="text/html;charset=gb2312"%>
<html><head><title>登陆系统</title></head>
<body>
<form name="login" action="check.jsp" method="post">
 用户:<input type="text" name="admin">

 密码:<input type="password" name="password">

 <input type="submit" value="登陆">

</form>
</body>
</html>
<%
 String error=request.getParameter("error");
 error=new String(error.getBytes("8859_1"),"gb2312");
 if(error==null) {}
 else{
  %>
  <%=error%>
  <%
 }
%>

check.jsp

<% page contentType="text/html;charset=gb2312"%>
<% page import="login.CheckBean"%>
<%
 String admin = request.getParameter("admin");
 String password = request.getParameter("password");
%>
<jsp:useBean id="checkBean" class="login.CheckBean"/>
<jsp:setProperty name="checkBean" property="admin" value="<%= admin.trim() %>"/>
<jsp:setProperty name="checkBean" property="password" value="<%= password.trim() %>"/>
<%
 String result = checkBean.checkIt();
 if(result.equals("密码正确!")){
  session.setAttribute("admin",admin);
  response.sendRedirect("main.jsp");
 }
 else
 {
  %>
  <jsp:forward page="index.jsp">
   <jsp:param name="error" value="<%=result%>"/>
  </jsp:forward>      
  <%
 }
%>

main.jsp

<% page contentType="text/html;charset=gb2312"%>
<%
 String admin =(String)(session.getAttribute("admin"));
 if(admin==null){
  response.sendRedirect("index.jsp");
 }
 else{
%>
<html><head><title>新闻发布</title></head>
<body>
<form name="pub" action="pub.jsp" method="post">
 题目:<input type="text" name="title">

 内容:<textarea cols="100" rows="10" name="context"></textarea>

 <input type="submit" value="提交">

</form>
</body>
</html>
<%}%>

pub.jsp

<% page contentType="text/html;charset=gb2312"%>
<%
 String admin = (String)(session.getAttribute("admin"));
 String title = request.getParameter("title");
 String context = request.getParameter("context");
 if(admin == null){
  response.sendRedirect("index.jsp");
 }
 else{
 %>
  <jsp:useBean id="pubBean" class="login.PubBean"/>
  <jsp:setProperty name="pubBean" property="title" value="<%= title.trim() %>"/>
  <jsp:setProperty name="pubBean" property="context" value="<%= context %>"/>
 <%
  pubBean.pubIt();
  response.sendRedirect("display.jsp");
 }
%>

display.jsp

<% page contentType="text/html;charset=gb2312"%>
<% page import="java.sql.*"%>
<%
 Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
 Connection conn=DriverManager.getConnection("jdbc:odbc:PostgreSQL","","");
 Statement stmt=conn.createStatement(); 
%>
<html><head><title>新闻</title></head>
<body>
<%
 ResultSet rs=stmt.executeQuery("SELECT * FROM news");
 //显示记录
 while(rs.next()){
  out.print("<a href=news/ice"+rs.getString(2)+".htm target=_blank>"+rs.getString

(1)+"</a>");
  out.println("
");
 }  %>
</body>
</html>

好了,基本的东西都实现了,希望现在已经可以给你一个完整的面貌了,在后面的文章中,我再把程序一步步

的完善,增加一些新的功能!

下面的是md5的算法在网上找的,转载一下:

package login;

import java.lang.reflect.*;

public class MD5 {
        /* 下面这些S11-S44实际上是一个4*4的矩阵,在原始的C实现中是用#define 实现的,
        这里把它们实现成为static final是表示了只读,切能在同一个进程空间内的多个
        Instance间共享*/
        static final int S11 = 7;
        static final int S12 = 12;
        static final int S13 = 17;
        static final int S14 = 22;

        static final int S21 = 5;
        static final int S22 = 9;
        static final int S23 = 14;
        static final int S24 = 20;

        static final int S31 = 4;
        static final int S32 = 11;
        static final int S33 = 16;
        static final int S34 = 23;

        static final int S41 = 6;
        static final int S42 = 10;
        static final int S43 = 15;
        static final int S44 = 21;

        static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
        /* 下面的三个成员是keyBean计算过程中用到的3个核心数据,在原始的C实现中
           被定义到keyBean_CTX结构中

         */
        private long[] state = new long[4];  // state (ABCD)
        private long[] count = new long[2];  // number of bits, modulo 2^64 (lsb first)
        private byte[] buffer = new byte[64]; // input buffer

        /* digestHexStr是keyBean的唯一一个公共成员,是最新一次计算结果的
          16进制ASCII表示.
        */
        public String digestHexStr;

        /* digest,是最新一次计算结果的2进制内部表示,表示128bit的keyBean值.
        */
        private byte[] digest = new byte[16];

        /*
          getkeyBeanofStr是类keyBean最主要的公共方法,入口参数是你想要进行keyBean变换的字符串
          返回的是变换完的结果,这个结果是从公共成员digestHexStr取得的.
        */
        public String getkeyBeanofStr(String inbuf) {
                keyBeanInit();
                keyBeanUpdate(inbuf.getBytes(), inbuf.length());
                keyBeanFinal();
                digestHexStr = "";
                for (int i = 0; i < 16; i++) {
                        digestHexStr += byteHEX(digest[i]);
                }
                return digestHexStr;

        }
        // 这是keyBean这个类的标准构造函数,JavaBean要求有一个public的并且没有参数的构造函数
        public MD5() {
                keyBeanInit();

                return;
        }

        /* keyBeanInit是一个初始化函数,初始化核心变量,装入标准的幻数 */
        private void keyBeanInit() {
                count[0] = 0L;
                count[1] = 0L;
                ///* Load magic initialization constants.

                state[0] = 0x67452301L;
                state[1] = 0xefcdab89L;
                state[2] = 0x98badcfeL;
                state[3] = 0x10325476L;

                return;
        }
        /* F, G, H ,I 是4个基本的keyBean函数,在原始的keyBean的C实现中,由于它们是
        简单的位运算,可能出于效率的考虑把它们实现成了宏,在java中,我们把它们
       实现成了private方法,名字保持了原来C中的。 */

        private long F(long x, long y, long z) {
                return (x & y) | ((~x) & z);

        }
        private long G(long x, long y, long z) {
                return (x & z) | (y & (~z));

        }
        private long H(long x, long y, long z) {
                return x ^ y ^ z;
        }

        private long I(long x, long y, long z) {
                return y ^ (x | (~z));
        }

       /*
          FF,GG,HH和II将调用F,G,H,I进行近一步变换
          FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
          Rotation is separate from addition to prevent recomputation.
       */

        private long FF(long a, long b, long c, long d, long x, long s,
                long ac) {
                a += F (b, c, d) + x + ac;
                a = ((int) a << s) | ((int) a >>> (32 - s));
                a += b;
                return a;
        }

        private long GG(long a, long b, long c, long d, long x, long s,
                long ac) {
                a += G (b, c, d) + x + ac;
                a = ((int) a << s) | ((int) a >>> (32 - s));
                a += b;
                return a;
        }
        private long HH(long a, long b, long c, long d, long x, long s,
                long ac) {
                a += H (b, c, d) + x + ac;
                a = ((int) a << s) | ((int) a >>> (32 - s));
                a += b;
                return a;
        }
        private long II(long a, long b, long c, long d, long x, long s,
                long ac) {
                a += I (b, c, d) + x + ac;
                a = ((int) a << s) | ((int) a >>> (32 - s));
                a += b;
                return a;
        }
        /*
         keyBeanUpdate是keyBean的主计算过程,inbuf是要变换的字节串,inputlen是长度,这个
         函数由getkeyBeanofStr调用,调用之前需要调用keyBeaninit,因此把它设计成private的
        */
        private void keyBeanUpdate(byte[] inbuf, int inputLen) {

                int i, index, partLen;
                byte[] block = new byte[64];
                index = (int)(count[0] >>> 3) & 0x3F;
                // /* Update number of bits */
                if ((count[0] += (inputLen << 3)) < (inputLen << 3))
                        count[1]++;
                count[1] += (inputLen >>> 29);

                partLen = 64 - index;

                // Transform as many times as possible.
                if (inputLen >= partLen) {
                        keyBeanMemcpy(buffer, inbuf, index, 0, partLen);
                        keyBeanTransform(buffer);

                        for (i = partLen; i + 63 < inputLen; i += 64) {

                                keyBeanMemcpy(block, inbuf, 0, i, 64);
                                keyBeanTransform (block);
                        }
                        index = 0;

                } else

                        i = 0;

                ///* Buffer remaining input */
                keyBeanMemcpy(buffer, inbuf, index, i, inputLen - i);

        }

        /*
          keyBeanFinal整理和填写输出结果
        */
        private void keyBeanFinal () {
                byte[] bits = new byte[8];
                int index, padLen;

                ///* Save number of bits */
                Encode (bits, count, 8);

                ///* Pad out to 56 mod 64.
                index = (int)(count[0] >>> 3) & 0x3f;
                padLen = (index < 56) ? (56 - index) : (120 - index);
                keyBeanUpdate (PADDING, padLen);

                ///* Append length (before padding) */
                keyBeanUpdate(bits, 8);

                ///* Store state in digest */
                Encode (digest, state, 16);

        }

        /* keyBeanMemcpy是一个内部使用的byte数组的块拷贝函数,从input的inpos开始把len长度的
      字节拷贝到output的outpos位置开始
        */

        private void keyBeanMemcpy (byte[] output, byte[] input,
                int outpos, int inpos, int len)
        {
                int i;

                for (i = 0; i < len; i++)
                        output[outpos + i] = input[inpos + i];
        }

        /*
           keyBeanTransform是keyBean核心变换程序,有keyBeanUpdate调用,block是分块的原始字节
        */
        private void keyBeanTransform (byte block[]) {
                long a = state[0], b = state[1], c = state[2], d = state[3];
                long[] x = new long[16];

                Decode (x, block, 64);

                /* Round 1 */
                a = FF (a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */
                d = FF (d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */
                c = FF (c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */
                b = FF (b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */
                a = FF (a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */
                d = FF (d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */
                c = FF (c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */
                b = FF (b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */
                a = FF (a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */
                d = FF (d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */
                c = FF (c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */
                b = FF (b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */
                a = FF (a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */
                d = FF (d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */
                c = FF (c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */
                b = FF (b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */

                /* Round 2 */
                a = GG (a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */
                d = GG (d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */
                c = GG (c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */
                b = GG (b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */
                a = GG (a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */
                d = GG (d, a, b, c, x[10], S22, 0x2441453L); /* 22 */
                c = GG (c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */
                b = GG (b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */
                a = GG (a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */
                d = GG (d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */
                c = GG (c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */
                b = GG (b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */
                a = GG (a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */
                d = GG (d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */
                c = GG (c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */
                b = GG (b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */

                /* Round 3 */
                a = HH (a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */
                d = HH (d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */
                c = HH (c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */
                b = HH (b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */
                a = HH (a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */
                d = HH (d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */
                c = HH (c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */
                b = HH (b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */
                a = HH (a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */
                d = HH (d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */
                c = HH (c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */
                b = HH (b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */
                a = HH (a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */
                d = HH (d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */
                c = HH (c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */
                b = HH (b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */

                /* Round 4 */
                a = II (a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */
                d = II (d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */
                c = II (c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */
                b = II (b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */
                a = II (a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */
                d = II (d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */
                c = II (c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */
                b = II (b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */
                a = II (a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */
                d = II (d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */
                c = II (c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */
                b = II (b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */
                a = II (a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */
                d = II (d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */
                c = II (c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */
                b = II (b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */

                state[0] += a;
                state[1] += b;
                state[2] += c;
                state[3] += d;

        }

        /*Encode把long数组按顺序拆成byte数组,因为java的long类型是64bit的,
          只拆低32bit,以适应原始C实现的用途
        */
        private void Encode (byte[] output, long[] input, int len) {
                int i, j;

                for (i = 0, j = 0; j < len; i++, j += 4) {
                        output[j] = (byte)(input[i] & 0xffL);
                        output[j + 1] = (byte)((input[i] >>> 8) & 0xffL);
                        output[j + 2] = (byte)((input[i] >>> 16) & 0xffL);
                        output[j + 3] = (byte)((input[i] >>> 24) & 0xffL);
                }
        }

        /*Decode把byte数组按顺序合成成long数组,因为java的long类型是64bit的,
          只合成低32bit,高32bit清零,以适应原始C实现的用途
        */
        private void Decode (long[] output, byte[] input, int len) {
                int i, j;

                for (i = 0, j = 0; j < len; i++, j += 4)
                        output[i] = b2iu(input[j]) |
                                (b2iu(input[j + 1]) << 8) |
                                (b2iu(input[j + 2]) << 16) |
                                (b2iu(input[j + 3]) << 24);

                return;
        }

        /*
          b2iu是我写的一个把byte按照不考虑正负号的原则的"升位"程序,因为java没有unsigned运算
        */
        public static long b2iu(byte b) {
                return b < 0 ? b & 0x7F + 128 : b;
        }

        /*byteHEX(),用来把一个byte类型的数转换成十六进制的ASCII表示,
         因为java中的byte的toString无法实现这一点,我们又没有C语言中的
          sprintf(outbuf,"%02X",ib)
        */
        public static String byteHEX(byte ib) {
                char[] Digit = { '0','1','2','3','4','5','6','7','8','9',
                'A','B','C','D','E','F' };
                char [] ob = new char[2];
                ob[0] = Digit[(ib >>> 4) & 0X0F];
                ob[1] = Digit[ib & 0X0F];
                String s = new String(ob);
                return s;
        }
/*
        public static void main(String args[]) {

                MD5 m = new MD5();
                System.out.println("我爱你:"+m.getkeyBeanofStr("我爱你"));
        }
        */

}



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