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一个J2EE实现的反面例子续（java代码）

摘录：java 来源：java 加入时间：2006年08月11日
摘要：
一个J2EE实现的反面例子续（java代码）

  1. Index.java
  2. import classnotepad.*;
  3. import javax.servlet.http.*;

  4. 转载：转载请保留本信息，本文来自
    http://www.51dibs.com
    /html/2006/article/info11/a_880f304f3f3a384c.htm

一个J2EE实现的反面例子续（java代码）

站点：爱心种子小博士 关键字：一个J2EE实现的反面例子续（java代

   
一个J2EE实现的反面例子续（java代码）
  1. Index.java
  2. import classnotepad.*;
  3. import javax.servlet.http.*;
  4. import javax.servlet.*;
  5. import java.io.*;
  6. public class index extends  {
  7.     public static ConnectionPool pool;
  8.     /** init the index servlet and init db connection pool*/
  9.     public void init( config) throws {
  10.         super.init(config);
  11.         pool = ConnectionPool.instance();
  12.         pool.createConnection();
  14.     }
  16.     public void doGet( request,  response) throws , {
  17.         response.setContentType("text/html; charset=gb2312");
  18.          out = response.getWriter();
  19.         out.println("<html>");
  20.         out.println("<title>XX同学留言簿</title>");
  21.         out.println("        <body bgColor=#456589 >");
  22.         out.println("            <head><CENTER><h2>XX同学留言簿登陆页面 </head>");
  23.         out.println("            <form action=/ustc9611/liuyan.jsp method=POST>");
  24.         out.println("              请输入登陆名 <CENTER>");
  25.         out.println("              姓名：<input type=text name=id><CENTER><BR>");
  26.         out.println("              请输入密码 <CENTER>");
  27.         out.println("              密码：<input type=password name=passwd><CENTER><BR>");
  28.         out.println("              <input type=submit value=确定><input type=reset value=取消><CENTER>");
  29.         out.println("            </form>");
  30.         out.println("            <form action=/ustc9611/zhuce.html method=POST>");
  31.         out.println("              注册新用户");
  32.         out.println("              <input type=submit value=确定>");
  33.         out.println("            </form>");
  34.         out.println("        <BR>");
  35.         out.println("        <form action=/ustc9611/visit.jsp method=POST>");
  36.         out.println("            查询同学最近登陆时间<input type=submit value=确定>");
  37.         out.println("        </form>");
  38.         out.println("        </body>");
  39.         out.println("</html>");
  40.     }
  41.     
  42.     public void doPost( request,  response) throws , {
  43.         doGet(request,response);
  44.     }
  45.     
  46.     /** destroy the index servlet and close the connections in pool*/
  47.     public void destroy(){
  48.         super.destroy();
  49.         pool.closeConnection();
  50.         pool = null;
  51.     }
  52. }
  53. LiuYanBean.java
  54. package classnotepad;
  55. import java.util.*;
  56. import java.io.*;
  57. import java.sql.*;
  58. import javax.servlet.jsp.*;
  59. public class LiuYanBean{
  60.     private  id;
  61.     private  text;
  62.     private  subject;
  63.     private  passwd;
  64.     
  65.     private  hash;
  66.     private  conn;
  67.     private  statement;
  68.     private  stmt;
  69.     private static int classID = 1;
  70.     private ConnectionPool pool;
  71.     
  72.     public LiuYanBean(){
  73.       id = null;
  74.       text = null;
  75.       pool = ConnectionPool.instance();
  76.     }
  77.     
  78.     /** id */
  79.     public void setId( ID){
  80.       id = ID;
  81.     }
  82.     public  getId(){
  83.       return id;
  84.     }
  85.     
  86.     /** passwd */
  87.     public  getPasswd(){
  88.       return passwd;
  89.     }
  90.     public void setPasswd( pwd){
  91.       passwd = pwd;
  92.     }
  93.     
  94.     /** text */
  95.     public void setText( ptext){
  96.       text = ptext;
  97.     }
  98.     public  getText(){
  99.       return text;
  100.     }
  101.     
  102.     /** subject */
  103.     public void setSubject( psub){
  104.       subject = psub;
  105.     }
  106.     public  getSubject(){
  107.       return subject;
  108.     }
  109.     
  110.     /** show the registed users leaved words */
  111.     public void show( out){
  112.       try{
  113.           openConnection();
  114.           statement = conn.createStatement();
  115.           
  116.            select = "select user_name,title,context,create_dt from coninfo where class_id ="
  117.                             +classID+" order by create_dt DESC";
  118.            set = statement.executeQuery(select);
  119.           while(set.next()){
  120.               out.println("留言人:"+set.getString(1));
  121.               out.println("<p>");
  122.               out.println("标题:"+set.getString(2));
  123.               out.println("<p>");
  124.               out.println("<pre>");
  125.           //    byte[] db = set.getString(3).getBytes("ISO-8859-1");
  126.               out.println( set.getString(3) );
  127.               out.println("</pre>");
  128.               out.println("<p>");
  129.               out.println("<right>留言时间:"+set.getString(4));
  130.               out.println("<p>");
  131.               out.println("<center>-------------------------------------------------------------------------------------------------------------------</center>");
  132.               out.println("<p>");
  133.               out.println("<BR>");
  134.           }
  135.       }catch( sqle){sqle.printStackTrace();}
  136.       catch( ioe){ioe.printStackTrace();}
  137. //      catch(java.io.UnsupportedEncodingException ue){ue.printStackTrace();}
  138.       finally{
  139.           closeConnection();
  140.       }
  141.     }
  142.     
  143.     /** show the registed users visiting dates */
  144.     public void showVisitDate( out){
  145.       try{
  146.           openConnection();
  147.           statement = conn.createStatement();
  148.            select = "select user_name,visit_dt from passwd where class_id ="
  149.                             +classID+" order by visit_dt DESC";
  150.            set = statement.executeQuery(select);
  151.           while(set.next()){
  152.             out.println("<pre>");
  153.               out.println("访问者:"+set.getString(1)+"        最新访问时间:"+set.getString(2));
  154.             out.println("---------------------------------------------------------------------------------------------------------------");
  155.               out.println("</pre>");
  156.           }
  157.       }catch( sqle){sqle.printStackTrace();}
  158.       catch( ioe){ioe.printStackTrace();}
  159. //      catch(java.io.UnsupportedEncodingException ue){ue.printStackTrace();}
  160.       finally{
  161.           closeConnection();
  162.       }
  163.     }
  165.     public void addLiuYan(){
  166.       if(subject==null || text==null)    return;
  167.       try{
  168.             openConnection();
  169.             statement = conn.createStatement();
  170.             java.util. dt = .getInstance().getTime();
  171.              insert = "insert into coninfo(class_id,user_name,title,context,create_dt) values("+classID+","
  172.                             //+new String(id.getBytes(),"ISO-8859-1")+","+new String(subject.getBytes(),"ISO-8859-1")+","+new String(text.getBytes(),"ISO-8859-1")+","+"Date())";//Date()是access的内部函数                            
  173.                             +id+","+subject+","+text+","+"getdate())";//Date()是access的内部函数                            
  174.             statement.executeUpdate(insert);
  175.       }catch( sqle){sqle.printStackTrace();}
  176. //      catch(java.io.UnsupportedEncodingException ue){ue.printStackTrace();}
  177.       finally{
  178.           closeConnection();
  179.       }
  180.     }
  181.     public boolean check(){
  182.         boolean flag = false;
  183.         if (id == null ) return flag;
  184.         try{
  186.             openConnection();
  187.             statement = conn.createStatement();
  188.              search = "select * from passwd where class_id = "+classID+" and user_name = "+id+" and passwd = "+passwd+"";
  189.              set = statement.executeQuery(search);
  190.             if(set.next()){
  191.                 flag = true;
  192.             }
  193.             
  194.             if(flag){
  195.                  buffer = new ();
  196.                 buffer.append("update passwd set visit_dt = getdate() where class_id = ");
  197.                 buffer.append(classID);
  198.                 buffer.append(" and user_name = ");
  199.                 buffer.append(id);
  200.                 buffer.append(" and passwd = ");
  201.                 buffer.append(passwd);
  202.                 buffer.append("");
  203.                 statement.executeUpdate(buffer.toString());
  204.             }
  205.         }catch( sqle){sqle.printStackTrace();
  206.         }finally{
  207.             closeConnection();
  208.         }
  209.         return flag;
  210.     }
  211.     
  212.     private void openConnection(){
  213.         hash  = pool.getConnection();
  214.         if(hash.elements().hasMoreElements()){
  215.             conn = ()hash.elements().nextElement();
  216.         }
  217.     }
  218.     
  219.     private void closeConnection(){
  220.         try{
  221.             if(statement!= null){
  222.                 statement.close();
  223.             }
  224.             if(stmt!=null){
  225.                 stmt.close();
  226.             }
  227.             statement = null;
  228.             stmt = null;
  230.             pool.putConnection(hash);
  231.         }catch( sqle){sqle.printStackTrace();}
  233.     }
  234. }
  235. UploadBean.java
  236. package classnotepad;
  237. import java.util.*;
  238. import java.io.*;
  239. import java.sql.*;
  240. import javax.servlet.jsp.*;
  241. public class UploadBean{
  242.     private  id;
  243.     private  passwd;
  244.     private  imageName;
  245.     private  subject;
  246.     
  247.     private  hash;
  248.     private  conn;
  249.     private  statement;
  250.     private  stmt;
  251.     private static int classID = 1;
  252.     private ConnectionPool pool;
  253.     
  254.     public UploadBean(){
  255.       id = null;
  256.       imageName = null;
  257.       pool = ConnectionPool.instance();
  258.     }
  259.     
  260.     /** id */
  261.     public void setId( ID){
  262.       id = ID;
  263.     }
  264.     public  getId(){
  265.       return id;
  266.     }
  267.     
  268.     /** passwd */
  269.     public  getPasswd(){
  270.       return passwd;
  271.     }
  272.     public void setPasswd( pwd){
  273.       passwd = pwd;
  274.     }
  275.     
  276.     
  277.     /** imageName */
  278.     public void setImageName( imgName){
  279.         imageName = imgName;
  280.     }
  281.     
  282.     public  getImageName(){
  283.         return imageName;
  284.     }
  286.     /** subject */
  287.     public void setSubject( sub){
  288.         subject = sub;
  289.     }
  290.     
  291.     public  getSubject(){
  292.         return subject;
  293.     }
  295.     public void addImageInfo(){
  296.       if( imageName == null )    return;
  297.       try{
  298.             openConnection();
  299.             statement = conn.createStatement();
  300.             java.util. dt = .getInstance().getTime();
  301.              insert = "insert into imageinfo(class_id,create_dt,image_name,title) values("+classID+","
  302.                             //+new String(id.getBytes(),"ISO-8859-1")+","+new String(subject.getBytes(),"ISO-8859-1")+","+new String(text.getBytes(),"ISO-8859-1")+","+"Date())";//Date()是access的内部函数                            
  303.                             +"getdate(),"+imageName+","+subject+")";//Date()是access的内部函数                            
  304.             statement.executeUpdate(insert);
  305.       }catch( sqle){sqle.printStackTrace();}
  306. //      catch(java.io.UnsupportedEncodingException ue){ue.printStackTrace();}
  307.       finally{
  308.           closeConnection();
  309.       }
  310.     }
  311.     
  312.     private void openConnection(){
  313.         hash  = pool.getConnection();
  314.         if(hash.elements().hasMoreElements()){
  315.             conn = ()hash.elements().nextElement();
  316.         }
  317.     }
  318.     
  319.     private void closeConnection(){
  320.         try{
  321.             if(statement!= null){
  322.                 statement.close();
  323.             }
  324.             if(stmt!=null){
  325.                 stmt.close();
  326.             }
  327.             statement = null;
  328.             stmt = null;
  330.             pool.putConnection(hash);
  331.         }catch( sqle){sqle.printStackTrace();}
  333.     }
  334. }
  335. AddUserBean.java
  336. package classnotepad;
  337. import java.util.*;
  338. import java.sql.*;
  339. public class AddUserBean{
  340.     private  id;
  341.     private  passwd;
  342.     private  confirm;
  343.     private  connection;
  344.     private  statement;
  345.     private  stmt;
  346.     private static  hash;
  347.     private ConnectionPool pool;
  348.     
  349.     public AddUserBean(){
  350.       id = null;
  351.       passwd = null;
  352.       pool = ConnectionPool.instance();
  353.     }
  354.     
  355.     public void setId( ID){
  356.       id = ID;
  357.     }
  358.     public  getId(){
  359.       return id;
  360.     }
  361.     public void setConfirm( con){
  362.       confirm = con;
  363.     }
  364.     public  getConfirm(){
  365.       return confirm;
  366.     }
  367.     public void setPasswd( pswd){
  368.       passwd = pswd;
  369.     }
  370.     public  getPasswd(){
  371.       return passwd;
  372.     }
  373.     public boolean isNewUser(){
  374.         try{
  375.             openConnection();
  376.             statement = connection.createStatement();
  377.              search = "select * from passwd where class_id=1 and user_name= "+id+"";
  378.              set = statement.executeQuery(search);
  379.             if( set.next()){
  380.                 return false;
  381.             }
  382.         }catch( sqle){sqle.printStackTrace();}
  383.         finally{closeConnection();}
  384.         return true;
  385.     }
  386.     
  387.     public boolean addUser(){
  388.       try{
  389.           openConnection();
  390.           statement = connection.createStatement();
  391.            insert = "insert into passwd(class_id,user_name,passwd) values( 1,"
  392.                           +""+this.id+","+this.passwd+")";
  393.           statement.executeUpdate(insert);
  394.           return true;
  395.       }catch( sqle){sqle.printStackTrace();}
  396.       finally{
  397.           closeConnection();
  398.       }
  399.       return false;
  400.     }
  401.     
  404.     private void openConnection(){
  405.         hash  = pool.getConnection();
  406.         if(hash.elements().hasMoreElements()){
  407.             connection = ()hash.elements().nextElement();
  408.         }
  409.     }
  410.     
  411.     private void closeConnection(){
  412.         try{
  413.             if(statement!= null){
  414.                 statement.close();
  415.             }
  416.             if(stmt!=null){
  417.                 stmt.close();
  418.             }
  419.             statement = null;
  420.             stmt = null;
  422.             pool.putConnection(hash);
  423.         }catch( sqle){sqle.printStackTrace();}
  425.     }
  426. }
  427. ConnectionPool.java
  428. package classnotepad;
  429. import java.sql.*;
  430. import java.util.*;
  431. public final class ConnectionPool{
  432.     private  static int DB_MAX = 4;
  433.     private  int STATUS_UNINIT = 1;//未初始化状态
  434.     private  int STATUS_PREPARED = 2;//已经初始化状态
  435.     private  int STATUS_INUSED = 3;//正在使用状态
  436.     private  int STATUS_CLOSED = 4;//关闭状态
  437.     private  int status[] = {STATUS_UNINIT,STATUS_UNINIT,STATUS_UNINIT,STATUS_UNINIT};
  438.     private  static boolean singleFlag = false;
  439.     private  static [] connection = new [DB_MAX];
  440.     private  final  sqlDriver = "sun.jdbc.odbc.JdbcOdbcDriver";
  441.     private  final  url = "jdbc:odbc:liuyan";
  442.     private  final  user = "administrator";
  443.     private  final  passwd = "";
  444.     private static ConnectionPool pool;
  445.     
  446.     /** singleton design pattern */
  447.     private ConnectionPool(){
  448.         for(int i =0;i < DB_MAX;i++){
  449.             connection[i] = null;
  450.         }
  451. //        createConnection();
  452.     }
  453.     
  454.     /** create a instance pool */
  455.     public static synchronized ConnectionPool instance(){
  456.         if(!singleFlag){
  457.             singleFlag = true;
  458.             pool = new ConnectionPool();
  459.         }
  460.         return pool;
  461.     }
  462.     
  463.     /** init connection pool */
  464. &nb;
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