java实现留言板功能实例
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2024-02-29 14:51:22
jsp+javabean的留言板技术
messages.html
jsp+javabean的留言板技术
<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>主题：</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="重新填写"></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%">主题:</td>
<td colspan="3"><%=mg.gettitle()%></td>
</tr>
<tr>
<td width="20%">内容:</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"; //定义驱动程序对象
string username="root"; //定义数据库用户名
string userpasswd=""; //定义数据库存取密码
string dbname="message"; //定义数据库名
string conurl="jdbc:mysql://localhost:3306/"+dbname;
try{class.forname(jdriver).newinstance(); //加载jdbc驱动程序
con=drivermanager.getconnection(conurl,username,userpasswd);
//连接数据库
}
catch(exception e){system.err.println(e.getmessage());}
}
public void setmessage(messagedata msg) {this.msg=msg;}
// 添加一条留言消息
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(); //关闭数据库连接
}
catch(exception e){ e.printstacktrace(); throw e;}
}
// 获得所有留言消息，并返回结果到jsp页面
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>
功能简单的留言板，但是清楚的说明了jsp+javabean技术的运用，需要的朋友可以参考