Java Web 网络留言板6 MVC模式

两种转向的区别：

　　forward()

request.setAttribute("message", message);   request.getRequestDispatcher("/addResult.jsp").forward(request, response);

　　sendRedirect()

  response.sendRedirect("/guestbook6/getMessages.jsp");

区别：

1、forward可以读取转向前request对象通过setAttribute()方法所设定的属性值，sendRedirect()不能；

2、转向后，forward()方法显示的是原来Servlet的地址，即地址不变，而sendRedirect(“*****”)方法要变成*****地址；

3、forward()方法转向的速度要快，较sendRedirect()方法；

4、sendRedirect()方法可以转向到web应用之外的页面或者网站，

　　如：response.sendRedirect(" http://www.cnblogs.com/hongten/ ");

　　而forward()是不可以的；

addMessage.jsp

代码：

<%@ page language="java" contentType="text/html; charset=UTF-8"%> <%@ include file="/header.jsp"%> <style> * { font-family: "宋体"; font-size: 14px } </style> <script type="text/javascript" src="<%=context%>/js/validation-framework.js"></script> <script type="text/javascript" src="<%=context%>/fckeditor/fckeditor.js"></script> <p align="center">  请您输入留言 </p> <p align="center">  <a href="<%=context%>/servlet/getMessages">查看留言</a> </p> <form id="form1" name="form1" method="post"  action="<%=context%>/servlet/addMessage"  onsubmit="return doValidate(this)">  <table width="650" height="400" border="0" align="center">   <tr>    <td width="150">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 = '<%=context%>/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> <%@ include file="/footer.htm"%>

OracleUtil.java

代码：

package webbook.util;

import java.sql.SQLException; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NamingException; import javax.sql.DataSource; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.ResultSetHandler;

public class OracleUtil {  private String dataSourceName;  private DataSource ds;

 public OracleUtil(String dataSourceName) {   this.dataSourceName = dataSourceName;    }

 public OracleUtil() {    }

 public void setDataSourceName(String dataSourceName) {   this.dataSourceName = dataSourceName;  }

 public void init() {   Context initContext;   try {    initContext = new InitialContext();    ds = (DataSource) initContext.lookup(dataSourceName);   } catch (NamingException e) {    e.printStackTrace();   }  }

 public int update(String sql, String[] param) {   int result = 0;   QueryRunner qr = new QueryRunner(ds);   try {    result = qr.update(sql, param);   } catch (SQLException e) {    e.printStackTrace();   }   return result;  }

 public Object query(String sql, String[] param, ResultSetHandler rsh) {   QueryRunner qr = new QueryRunner(ds);   Object result = null;   try {    result = qr.query(sql, param, rsh);   } catch (SQLException e) {    e.printStackTrace();   }   return result;  } }

AddMessageServlet.java

代码：

package webbook.guestbook;

import java.io.IOException; import java.text.SimpleDateFormat; import javax.servlet.ServletException; import javax.servlet.http.*; import webbook.util.*;

public class AddMessageServlet extends HttpServlet {  private static final long serialVersionUID = -8349454122547148005L;

 public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {   String sql = "insert into guestbook (id,name,email,phone,title,content,time) values(gb_seq.nextval,?,?,?,?,?,?)";   int result = 0;   String message = "";   request.setCharacterEncoding("utf-8");   String name = request.getParameter("name");   String title = request.getParameter("title");

  if (StringUtil.validateNull(name)) {    message = "对不起，姓名不能为空，请您重新输入！<br>";   } else if (StringUtil.validateNull(title)) {    message = "对不起，主题不能为空，请您重新输入！<br>";   } else {  SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");    String param[] = { StringUtil.filterHtml(name), StringUtil.filterHtml(request.getParameter("email")),      StringUtil.filterHtml(request.getParameter("phone")), StringUtil.filterHtml(title),      request.getParameter("content"), sdf.format(new java.util.Date()) };    OracleUtil db = new OracleUtil("java:/comp/env/jdbc/oracleds");    db.init();    result = db.update(sql, param);    if (result == 0) {     message = "对不起，添加留言不成功，请您重新输入！<BR>";    } else {     message = "祝贺您，成功添加留言。<BR>";    }   }   request.setAttribute("message", message);   request.getRequestDispatcher("/addResult.jsp").forward(request, response);  } }

addResult.jsp

代码：

<%@ page language="java" contentType="text/html; charset=UTF-8"%> <%@ include file="/header.jsp" %> <style> * { font-family: "宋体";font-size: 14px} </style> <%=request.getAttribute("message")%> <a href="<%=context %>/addMessage.jsp">添加新的留言</a><BR> <a href="<%=context %>/servlet/getMessages">查看所有留言内容</a><BR> <%@ include file="/footer.htm"%>

getMessages.jsp

代码：

<%@ page language="java" contentType="text/html; charset=UTF-8"%> <%@page import="webbook.guestbook.Guestbook"%> <%@ include file="/header.jsp"%> <style> * {font-family: "宋体";font-size: 14px} </style> <center>  <a href="<%=context%>/addMessage.jsp">添加新的留言内容</a><br>  留言内容<br><br>  <% List list = (List)session.getAttribute("results");    if(list!=null){   for (int i = 0; i < list.size(); i++) {    Guestbook gb = (Guestbook) list.get(i);  %>  <table width="600" border="1" bordercolor="000000"   style="table-layout: fixed; word-break: break-all">   <tr>    <td width="100" bordercolor="ffffff">     编号:    </td>    <td width="500" bordercolor="ffffff"><%=gb.getId()%></td>   </tr>   <tr>    <td bordercolor="ffffff">     姓名:    </td>    <td bordercolor="ffffff"><%=gb.getName()%></td>   </tr>   <tr>    <td bordercolor="ffffff">     电话:    </td>    <td bordercolor="ffffff"><%=StringUtil.chanageNull(gb.getPhone(), "没填")%></td>   </tr>   <tr>    <td bordercolor="ffffff">     email:    </td>    <td bordercolor="ffffff"><%=StringUtil.chanageNull(gb.getEmail(), "没填")%></td>   </tr>   <tr>    <td bordercolor="ffffff">     主题:    </td>    <td bordercolor="ffffff"><%=gb.getTitle()%></td>   </tr>   <tr>    <td valign="top" bordercolor="ffffff">     内容:    </td>    <td valign="top" bordercolor="ffffff"><%=StringUtil.chanageNull(gb.getContent(), "没填")%></td>   </tr>   <tr>    <td bordercolor="ffffff">     时间:    </td>    <td bordercolor="ffffff"><%=gb.getTime()%></td>   </tr>  </table>  <br>  <%}}%> </center> <%@ include file="/footer.htm"%>

GetMessagesServlet.java

代码：

package webbook.guestbook;

import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.*; import org.apache.commons.dbutils.handlers.BeanListHandler; import webbook.util.OracleUtil;

public class GetMessagesServlet extends HttpServlet {  private static final long serialVersionUID = 5964428201228635704L;

 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {   String sql = "select * from guestbook order by id desc";   List list = null;  OracleUtil db = new OracleUtil("java:/comp/env/jdbc/oracleds");   db.init();   list = (List) db.query(sql, null, new BeanListHandler(Guestbook.class));   HttpSession session = request.getSession();   session.setAttribute("results", list);   response.sendRedirect("/guestbook6/getMessages.jsp");  } }

Guestbook.java

代码：

package webbook.guestbook;

public class Guestbook {  private String content;  private String email;  private Integer id;  private String name;  private String phone;  private String time;  private String title;

 public String getContent() {   return content;  }

 public void setContent(String content) {   this.content = content;  }

 public String getEmail() {   return email;  }

 public void setEmail(String email) {   this.email = email;  }

 public Integer getId() {   return id;  }

 public void setId(Integer id) {   this.id = id;  }

 public String getName() {   return name;  }

 public void setName(String name) {   this.name = name;  }

 public String getPhone() {   return phone;  }

 public void setPhone(String phone) {   this.phone = phone;  }

 public String getTime() {   return time;  }

 public void setTime(String time) {   this.time = time;  }

 public String getTitle() {   return title;  }

 public void setTitle(String title) {   this.title = title;  } }