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(" 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"%> <% 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"); %> <% String result = checkBean.checkIt(); if(result.equals("密码正确!")){ session.setAttribute("admin",admin); response.sendRedirect("main.jsp"); } else { %> <% } %> main.jsp <%@ page contentType="text/html;charset=gb2312"%> <% String admin =(String)(session.getAttribute("admin")); if(admin==null){ response.sendRedirect("index.jsp"); } else{ %> <%}%> 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{ %> <% 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(); %> <% ResultSet rs=stmt.executeQuery("SELECT * FROM news"); //显示记录 while(rs.next()){ out.print(""+rs.getString (1)+""); out.println(" "); } %> 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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