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"><br>  密码:<input type="password" name="password"><br>  <input type="submit" value="登陆"><br> </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"><br>  内容:<textarea cols="100" rows="10" name="context"></textarea><br>  <input type="submit" value="提交"><br> </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("<br>");  }  %> </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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