BeanUtils数据封装与表单JavaBean

时间:2023-03-09 18:10:50
BeanUtils数据封装与表单JavaBean


一.BeanUtils工具的解释

(1)Apache的Commons组件中。提供了一个实用的工具类BeanUtils,利用它可以方便的将表单数据值填充值Bean中;

(2)javax.servlet.ServletRequest.getParameterMap()

在ServletRequest接口中,getParameter()方法的作用在于将client传来的參数封装在一个Map对象中,致谢參数能够通过GET POST

方法提交;

(3)org.apache.commons.beanutils.BeanUtils.populate()

这种方法的作用是将存储在Map中的參数填入给定的一个JavaBean对象中;

BeanUtils.populate(),第一个形參是一个bean对象,也就是表单的JavaBean,第二个形參是一个Map对象。也就是存储有表单圆度的Map对象;

二.举例具体解释

(1)编写一个JavaBean程序类RegForm

package my;
public class RegForm
{
private String userName;
private String password;
private String sect;
private String hobby[];
private String memo; public void setUserName(String s)
{
userName=s;
}
public String getUserName()
{
return userName;
}
public void setPassword(String s)
{
password=s;
}
public String getPassword()
{
return password;
} public void setSect(String s)
{
sect=s;
}
public String getSect()
{
return sect;
} public void setHobby(String s[])
{
hobby=s;
}
public String[] getHobby()
{
return hobby;
}
public void setMemo(String s)
{
memo=s;
}
public String getMemo()
{
return memo;
}
}

(2)新建一个填写数据的表单

<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head> <body>
<jsp:useBean id="my" class="my.RegForm" scope="page"/>
<jsp:setProperty name="my" property="*"/> //反射机制将表单自己主动填到‘my’表单中
<br>您的username是:<jsp:getProperty name="my" property="userName"/>
<br>您的口令是: <jsp:getProperty name="my" property="password"/>
<br>您的性别是:<jsp:getProperty name="my" property="sect"/>
<br>您的爱好是:
<%
String h[]=my.getHobby();
if(h!=null)
for(int i=0;i<h.length;i++)
out.print(h[i]);
%>
<br>您的附言是:<jsp:getProperty name="my" property="userName"/>
</body>
</html>

(3)新建一个Servlet程序    reformServlet处理表单

package my;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import org.apache.commons.beanutils.*; public class RegFormServlet extends HttpServlet
{
protected void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException,java.io.IOException
{
ServletContext application=getServletContext() ;
ServletConfig config=getServletConfig() ;
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
HttpSession session =request.getSession();
request.setCharacterEncoding("gb2312"); RegForm form=new RegForm();
Map map=request.getParameterMap();
try
{
BeanUtils.populate(form,map);
}catch(Exception e)
{
System.out.println("表单处理出错:"+e);
} out.print("<br>您的姓名是:"+form.getUserName());
out.print("<br>您的口令是:"+form.getPassword());
out.print("<br>您的性别是:"+form.getSect());
out.print("<br>您的爱好是:");
String h[]=form.getHobby();
if(h!=null)
for(int i=0;i<h.length;i++)
out.print(h[i]);
out.print("<br>您的附言是:"+form.getMemo());
} protected void doPost(HttpServletRequest request,HttpServletResponse response)
throws ServletException,java.io.IOException
{
doGet(request,response);
}
}

(4)另一个创建数据的界面

<%@ page contentType="text/html; charset=utf-8" language="java" import="java.sql.*" errorPage="" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head> <body>
<form id="form1" name="form1" method="post" action="exam.jsp">
<p>会员注冊信息</p>
<p>username:
<label>
<input name="userName" type="text" id="userName" />
</label>
</p>
<p>口令:
<label>
<input name="password" type="password" id="password" />
</label>
</p>
<p>性别:
<label>
<input name="sect" type="radio" value="男" checked="checked" />
</label>

<label>
<input type="radio" name="sect" value="女" />
</label>
女</p>
<p>爱好:
<label>
<input name="hobby" type="checkbox" id="hobby" value="篮球" />
</label>
篮球
<label>
<input name="hobby" type="checkbox" id="hobby" value="排球" />
</label>
排球
<label>
<input name="hobby" type="checkbox" id="hobby" value="足球" />
</label>
足球</p>
<p>附言:
<label>
<textarea name="memo" id="memo"></textarea>
</label>
<label>
<input type="submit" name="Submit" value="提交" />
</label>
</p>
</form>
</body>
</html>

(5)关于servlet的部署省去过程

(6)ok!