java實(shí)現(xiàn)留言板功能實(shí)例

更新時(shí)間：2017年04月14日 14:38:51 投稿：wbb

這篇文章主要為大家詳細(xì)介紹了JSP+JavaBean的留言板技術(shù) ,JavaWeb登陸功能實(shí)現(xiàn)代碼,具有一定的參考價(jià)值,感興趣的小伙伴們可以參考一下

JSP+JavaBean的留言板技術(shù)

<span style="font-size:16px;">Messages.html 
<HTML></span><span style="font-size:16px;"><HEAD> <TITLE> message board </TITLE></HEAD> 
<BODY> <center>留言板</center> 
<FORM action="addMessage.jsp" > 
 <TABLE border=1 align="center"> 
 <TR><TD>姓名：</TD><TD><input type="text" name="name" size=25> 
  </TD></TR> 
 <TR><TD>E-mail：</TD> 
  <TD><input type="text" name="email" size=25></TD></TR> 
 <TR><TD>主題：</TD> 
  <TD><input type="text" name="title" size=25></TD></TR> 
  <TR><TD>留言：</TD> 
  <TD><textarea name="content" rows=7 cols=25></textarea> 
  </TD></TR> 
  <TR><TD colspan=3> 
<TABLE align="center" width="100%" cellspacing="0" cellpadding="0" > 
  <TR> 
   <TD align="center"><input type="submit" value="提交留言"></TD> 
  <TD align="center"> 
  <a href="viewMessages.jsp" rel="external nofollow" ><font size=2>查看留言</font></a></TD> 
  <TD align="center"><input type="reset" value="重新填寫"></TD> 
  </TR></TABLE></TD> </TR></TABLE></FORM></BODY></HTML></span>
?
<span style="font-size:16px;">MessageData.java 
package message; 
public class MessageData  
 { private String name,email,title,content; 
  //setter或者getter方法 
  public void setName(String name){this.name=name;} 
  public void setEmail(String email){ this.email=email;} 
  public void setTitle(String title){ this.title=title;} 
  public void setContent(String content){this.content=content;} 
  public String getName(){ return this.name;} 
  public String getContent(){ return this.content;} 
  public String getTitle(){ return this.title;} 
  public String getEmail(){ return this.email;}}</span>
?
<span style="font-size:16px;">viewMessages.jsp 
  <%@ page contentType="text/html; charset=GBK" import="message.MessageData" %> 
<%@ page import="java.util.*"%> 
<jsp:useBean id="myBean" class="message.MessageBean" scope="page"/> 
<HTML><HEAD><TITLE> show the message in the table </TITLE></HEAD> 
<BODY><p align="center">所有留言</p> 
 <TABLE align="center" width="80%" border=1 > 
 <%   
  int message_count=0; 
  Collection <MessageData> messages=myBean.getAllMessage(); 
  Iterator <MessageData> it=messages.iterator(); 
  while(it.hasNext()){ MessageData mg=(MessageData)it.next();   
 %> 
  <tr> 
    <td width="20%">留言人:</td> 
    <td width="23%"><%=mg.getName()%></td> 
    <td width="58%" align="center"><% out.println( 
  "<a href=mailto:"+mg.getEmail()+">"+mg.getEmail()+"</a>"); 
%></td></tr> 
  <tr> 
    <td width="20%">主題:</td> 
    <td colspan="3"><%=mg.getTitle()%></td> 
  </tr> 
  <tr> 
    <td width="20%">內(nèi)容:</td> 
    <td colspan="3"><%=mg.getContent()%></td> 
  </tr> 
  <% message_count++; 
 }  
  %> 
 </Table> 
<p align="center"><a href="Messages.html" rel="external nofollow" >我要留言</a></p> 
</body></html></span>
?
<span style="font-size:16px;">addMessage.jsp 
<%@ page language="java" contentType="text/html; charset=GBK"
  pageEncoding="GBK"%> 
<jsp:useBean id="Mdata" class="message.MessageData" scope="page"> 
  <jsp:setProperty name="Mdata" property="*"/></jsp:useBean> 
<jsp:useBean id="myBean" class="message.MessageBean" scope="page"/> 
<HTML><HEAD><TITLE> message into table </TITLE></HEAD> 
<BODY> 
<% try { myBean.setMessage(Mdata);  myBean.addMessage(); } 
  catch(Exception e) { e.printStackTrace();} 
%> 
<jsp:forward page="viewMessages.jsp" /> 
</body></html></span>
?
<span style="font-size:16px;">MessageData.java 
package message; 
public class MessageData  
 { private String name,email,title,content; 
  //setter或者getter方法 
  public void setName(String name){this.name=name;} 
  public void setEmail(String email){ this.email=email;} 
  public void setTitle(String title){ this.title=title;} 
  public void setContent(String content){this.content=content;} 
  public String getName(){ return this.name;} 
  public String getContent(){ return this.content;} 
  public String getTitle(){ return this.title;} 
  public String getEmail(){ return this.email;}}</span>
?
<span style="font-size:16px;">MessageBean.java 
package message; 
import java.sql.*;  //引入java.sql包 
import java.util.*; 
public class MessageBean { 
  private Connection con;   MessageData msg; 
  public MessageBean() 
  { String JDriver="com.mysql.jdbc.Driver"; //定義驅(qū)動(dòng)程序?qū)ο? 
   String userName="root"; //定義數(shù)據(jù)庫用戶名  
   String userPasswd=""; //定義數(shù)據(jù)庫存取密碼  
   String dbName="message"; //定義數(shù)據(jù)庫名  
   String conURL="jdbc:mysql://localhost:3306/"+dbName; 
   try{Class.forName(JDriver).newInstance(); //加載JDBC驅(qū)動(dòng)程序 
  con=DriverManager.getConnection(conURL,userName,userPasswd);  
  //連接數(shù)據(jù)庫 
    } 
  catch(Exception e){System.err.println(e.getMessage());} 
  } 
  public void setMessage(MessageData msg) {this.msg=msg;} 
  //  添加一條留言消息 
  public void addMessage()throws Exception 
  { try{ byte b1[]=msg.getTitle().getBytes("ISO-8859-1"); 
      String ti=new String(b1); 
      byte b2[]=msg.getName().getBytes("ISO-8859-1"); 
      String na=new String(b2); 
      byte b3[]=msg.getEmail().getBytes("ISO-8859-1"); 
      String em=new String(b3); 
      byte b4[]=msg.getContent().getBytes("ISO-8859-1"); 
      String c=new String(b4); 
      PreparedStatement stm=con.prepareStatement( 
  "insert into messagetable values(?,?,?,?)"); 
      stm.setString(1,ti); stm.setString(2,na); 
      if((msg.getEmail()).length()==0)stm.setString(3,""); 
      else stm.setString(3,em);   
      stm.setString(4,c); 
      try {stm.execute();  stm.close(); }  
      catch(Exception e) { }       
      con.close(); //關(guān)閉數(shù)據(jù)庫連接 
    } 
    catch(Exception e){ e.printStackTrace(); throw e;} 
  } 
  //  獲得所有留言消息，并返回結(jié)果到JSP頁面 
 public Collection<MessageData> getAllMessage()throws Exception 
  { Collection<MessageData> ret=new ArrayList<MessageData>(); 
  try{ Statement stm=con.createStatement(); 
     ResultSet result=stm.executeQuery( 
  "select count(*) from messagetable");     
    int message_count=0; 
    if(result.next()){ message_count=result.getInt(1); 
        result.close(); } 
    if(message_count>0) 
    { result=stm.executeQuery("select * from messagetable "); 
   while(result.next()) 
  { String title=result.getString("title"); 
     String name=result.getString("name"); 
     String email=result.getString("email"); 
     String content=result.getString("content"); 
     MessageData message=new MessageData(); 
     message.setTitle(title); message.setName(name); 
  message.setEmail(email); message.setContent(content); 
  ret.add(message);             
    } 
    result.close();   stm.close(); 
   }      
  con.close();     
  } 
  catch(Exception e) 
   { e.printStackTrace(); throw e; } 
  return ret; 
  } 
}</span>

功能簡(jiǎn)單的留言板，但是清楚的說明了JSP+JavaBean技術(shù)的運(yùn)用，需要的朋友可以參考

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