java实现简单留言板功能的代码实例
java实现简单留言板功能的代码实例
数据库对应的表：
guestbook：id ,name,phone,email,title,content,time; <pk>id
新建web project：guestbook
build Path：引入连接数据库的驱动的类库
在webRoot目录中加入：
+faceditor
+js
web.xml
代码：
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<servlet-name>AddMessageServlet</servlet-name>
<servlet-class>webbook.guestbook.AddMessageServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>GetMessagesServlet</servlet-name>
<servlet-class>webbook.guestbook.GetMessagesServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AddMessageServlet</servlet-name>
<url-pattern>/servlet/addMessage</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>GetMessagesServlet</servlet-name>
<url-pattern>/servlet/getMessages</url-pattern>
</servlet-mapping>
</web-app>
addMessage.htm
代码：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/css" src="/guestbook/js/validation-framework.js"></script>
<script type="text/javascript" src="/guestbook/fckeditor/fckeditor.js"></script>
<title>add message</title>
</head>
<body>
<p align="center">请您输入留言</p>
<p align="center"><a href="/guestbook/servlet/getMessages">查看留言</a></p>
<form id="form1" name="form1" method="post" action="/guestbook/servlet/addMessage" onsubmit="return doValidate(this)">
<table width="600" height="400" border="0" align="center">
<tr>
<td width="100">姓名：</td>
<td width="500">
<input name="name" type="text" id="name" size="40" maxlength="20" />
</td>
</tr>
<tr>
<td>E-Mail：</td>
<td>
<input name="email" type="text" id="email" size="40" maxlength="40" />
</td>
</tr>
<tr>
<td>电话：</td>
<td>
<input name="phone" type="text" id="phone" size="40" maxlength="20" />
</td>
</tr>
<tr>
<td>主题：</td>
<td>
<input name="title" type="text" id="title" size="80" maxlength="80" />
</td>
</tr>
<tr>
<td valign="top">内容：</td>
<td>
<script type="text/javascript">
var oFCKeditor = new FCKeditor("content");
oFCKeditor.BasePath = '/guestbook/fckeditor/' ;
oFCKeditor.Height = 300 ;
oFCKeditor.ToolbarSet = 'Basic';
oFCKeditor.Create() ;
</script>
</td>
</tr>
<tr>
<td></td>
<td>
<input type="submit" name="Submit" value="提交" />
<input type="reset" name="Reset" value="重置" />
</td>
</tr>
</table>
</form>
</body>
</html>
content.html
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>display content</title>
</head>
<body>
<div align="center">
留言内容
<br />
<br />
<table width="357" height="107" border="1">
<tr>
<td width="48" >编号</td>
<td width="293" align="left">12</td>
</tr>
<tr>
<td>姓名</td>
<td align="left">liuwei</td>
</tr>
<tr>
<td>电话</td>
<td align="left">2922266</td>
</tr>
<tr>
<td>email</td>
<td align="left">phpa@www.3ppt.com</td>
</tr>
<tr>
<td>主题</td>
<td align="left">you can test </td>
</tr>
<tr height="50">
<td valign="top">内容</td>
<td valign="top" align="left">test content! </td>
</tr>
</table>
<p> </p>
<table width="357" height="107" border="1" align="center">
<tr>
<td width="48">编号</td>
<td width="293"> </td>
</tr>
<tr>
<td>姓名</td>
<td> </td>
</tr>
<tr>
<td>电话</td>
<td> </td>
</tr>
<tr>
<td>email</td>
<td> </td>
</tr>
<tr>
<td>主题</td>
<td> </td>
</tr>
<tr>
<td>内容</td>
<td> </td>
</tr>
</table>
<p> </p>
<table width="357" height="107" border="1" align="center">
<tr>
<td width="48">编号</td>
<td width="293"> </td>
</tr>
<tr>
<td>姓名</td>
<td> </td>
</tr>
<tr>
<td>电话</td>
<td> </td>
</tr>
<tr>
<td>email</td>
<td> </td>
</tr>
<tr>
<td>主题</td>
<td> </td>
</tr>
<tr>
<td><p>内容</p>
<p> </p>
<p> </p></td>
<td> </td>
</tr>
</table>
</div>
</body>
</html>
validation-config.xml
代码；
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE validation-config SYSTEM "validation-config.dtd">
<validation-config lang="auto">
<form id="form1" show-error="alert" show-type="all">
<field name="name" display-name="姓名" onfail="">
<depend name="required" />
<depend name="minLength" param0="2" />
<depend name="maxLength" param0="20" />
</field>
<field name="title" display-name="主题">
<depend name="required" />
</field>
<field name="email" display-name="email">
<depend name="email" />
</field>
</form>
</validation-config>
---------------------------------------------------------------------
******************************************************
这是一个很有用的工具类，包含了：
判读字符串参数是否为空：validateNull(String args)
判断输入的字符串参数是否为空或者是"null"字符：chanageNull(String source, String target)
过滤<, >,n 字符的方法：filterHtml(String input)
*****************************************************
---------------------------------------------------------------------
StringUtil.java
代码：
package webbook.util;
public class StringUtil {
/**
* 判断输入的字符串参数是否为空。
* @param args 输入的字串
* @return true/false
*/
public static boolean validateNull(String args) {
if (args == null || args.length() == 0) {
return true;
} else {
return false;
}
}
/**
* 判断输入的字符串参数是否为空或者是"null"字符,如果是,就返回target参数,如果不是,就返回source参数。
*/
public static String chanageNull(String source, String target) {
if (source == null || source.length() == 0 || source.equalsIgnoreCase("null")) {
return target;
} else {
return source;
}
}
/**
* 过滤<, >,n 字符的方法。
* @param input 需要过滤的字符
* @return 完成过滤以后的字符串
*/
public static String filterHtml(String input) {
if (input == null) {
return null;
}
if (input.length() == 0) {
return input;
}
input = input.replaceAll("&", "&");
input = input.replaceAll("<", "<");
input = input.replaceAll(">", ">");
input = input.replaceAll(" ", " ");
input = input.replaceAll("'", "'");
input = input.replaceAll(""", """);
input = input.replaceAll("n", "<br>");
return input;
}
}
AddmessageServlet.java
代码；
package webbook.guestbook;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.text.SimpleDateFormat;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import webbook.util.StringUtil;
public class AddMessageServlet extends HttpServlet {
private static final long serialVersionUID = -8349454122547148005L;
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String url = "jdbc:oracle:thin:@192.168.1.20:1521:ora9";
String username = "scott";
String password = "tiger";
String sql = "insert into guestbook (id,name,email,phone,title,content,time) values(gb_seq.nextval,?,?,?,?,?,?)";
int result = 0;
Connection conn = null;
request.setCharacterEncoding("utf-8");
String name = request.getParameter("name");
String title = request.getParameter("title");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head><title>guestbook input page</title></head>");
out.println("<body>");
if (StringUtil.validateNull(name)) {
out.println("对不起，姓名不能为空，请您重新输入！<br>");
out.println("<a href=""+request.getContextPath()+"/addMessage.htm">添加新的留言</a><br>");
} else if (StringUtil.validateNull(title)) {
out.println("对不起，主题不能为空，请您重新输入！<br>");
out.println("<a href=""+request.getContextPath()+"/addMessage.htm">添加新的留言</a><br>");
} else {
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection(url, username, password);
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, StringUtil.filterHtml(name));
pstmt.setString(2, StringUtil.filterHtml(request.getParameter("email")));
pstmt.setString(3, StringUtil.filterHtml(request.getParameter("phone")));
pstmt.setString(4, StringUtil.filterHtml(title));
pstmt.setString(5, request.getParameter("content"));
//设置格式化时间
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
pstmt.setString(6, sdf.format(new java.util.Date()));
result = pstmt.executeUpdate();
pstmt.close();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (result == 0) {
out.println("对不起，添加留言不成功，请您重新输入！<br>");
out.println("<a href=""+request.getContextPath()+"/addMessage.htm">添加新的留言</a><br>");
} else {
out.println("祝贺您，成功添加留言。<br>");
out.println("<a href=""+request.getContextPath()+"/servlet/getMessages">查看所有留言内容</a><br>");
}
out.println("</body>");
out.println("</html>");
out.flush();
out.close();
}
}
}
GetMessageServlet.java
代码：
package webbook.guestbook;
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import webbook.util.StringUtil;
public class GetMessagesServlet extends HttpServlet {
private static final long serialVersionUID = 5964428201228635704L;
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String url = "jdbc:oracle:thin:@192.168.1.20:1521:ora9";
String username = "scott";
String password = "tiger";
String sql = "select * from guestbook order by id desc";
Connection conn = null;
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head><title>display messages</title></head>");
out.println("<body>");
out.println("<a href="" + request.getContextPath() + "/addMessage.htm">添加新的留言内容</a><br>");
out.println("留言内容<br><br>");
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection(url, username, password);
PreparedStatement pstmt = conn.prepareStatement(sql);
//查询结果是一个ResultSet对象。
ResultSet rs = pstmt.executeQuery();
while (rs.next()) {
this.printRow(out, rs);
}
rs.close();
pstmt.close();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
out.println(" </body>");
out.println("</html>");
out.flush();
out.close();
}
private void printRow(PrintWriter out, ResultSet rs) throws SQLException {
out.println("<table width="600" border="1" style="table-layout:fixed;word-break:break-all">");
out.println("<tr><td width="50">编号</td>");
out.println("<td width="550">" + rs.getInt("id") + "</td></tr>");
out.println("<tr><td>姓名</td><td>" + rs.getString("name") + "</td></tr>");
out.println("<tr><td>电话</td><td>" +
StringUtil.chanageNull(rs.getString("phone"), "没填") +
"</td></tr>");
out.println("<tr><td>email</td><td>" +
StringUtil.chanageNull(rs.getString("email"), "没填") +
"</td></tr>");
out.println("<tr><td valign="top">主题</td><td>" + rs.getString("title") + " </td></tr>");
out.println("<tr><td valign="top">内容</td>");
out.println("<td>" + StringUtil.chanageNull(rs.getString("content"), "没填") + "</td></tr>");
out.println("<tr><td>时间</td><td>" + rs.getString("time") + " </td></tr>");
out.println("</table><br>");
}
}
