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BeanUtils数据封装与表单JavaBean

一.BeanUtils工具的解释

(1)Apache的Commons组件中,提供了一个有用的工具类BeanUtils,利用它能够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()方法的作用在于将客户端传来的参数封装在一个Map对象中,致谢参数可以通过GET POST

方法提交;

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

这个方法的作用是将存储在Map中的参数填入给定的一个JavaBean对象中;

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

二.举例详解

(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="*"/> //反射机制将表单自动填到‘my’表单中
<br>您的用户名是:<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)还有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>会员注册信息</p>
  <p>用户名:
    <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=http://www.mamicode.com/"男" checked="checked" />>

(5)关于servlet的部署省去过程


(6)ok!


BeanUtils数据封装与表单JavaBean