21.验证TextArea - struts2 - ITeye知识库频道

群组首页 → 企业架构 → struts2 → 知识库 → Struts2 教程 → 21.验证TextArea

原创作者: 饕尽天下阅读:6888次评论:2条更新时间:2011-06-01

在本章你将学习在struts2中如何验证你的text area.一个textarea包含1至250个字符,它不支持"null"值.

为了验证你的textarea请遵循下面的步骤.

第一步 : 创建index.jsp页面

这是要添加到index.jsp的代码 :

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>RoseIndia.Net Struts 2 Tutorial</title>
</head>

<body>
<div align="center">
<center>
<table border="0" cellpadding="0" cellspacing="0" width="400">
<tr>
<td><font color="#000080" size="5"><b>RoseIndia.net Struts 2 Tutorials</b><br>
&nbsp;&nbsp;&nbsp;</font></td>
</tr>
<tr>
<td><font color="#000080"><b>Select the following links to test the
examples</b></font></td>
</tr>
<tr>
<td>

<ul>
<li><a href="roseindia/characterLimit.action">Characters and limiting Example</a></li>
</ul>


</td>
</tr>
<tr>
<td><font color="#000080">&nbsp;<br>
&nbsp;<br>
&nbsp;<br>
Visit <a href="http://www.roseindia.net">http://www.roseindia.net</a>
for latest tutorials</font></td>
</tr>
</table>
</center>
</div>
<p align="center">&nbsp;</p>
</body>
</html>

第二步 : 在struts.xml中创建Action映射 :

这是要添加到struts.xml文件中的代码 :

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
<!-- Rose India Struts 2 Tutorials -->
<constant name="struts.enable.DynamicMethodInvocation" value="false" />
<constant name="struts.devMode" value="true" />

<package name="roseindia" namespace="/roseindia" extends="struts-default">

<action name="characterLimit">
<result>/pages/chatQuestion/limitedCharacter.jsp</result>
</action>

<action name="characterLimit1" class="net.roseindia.limitedCharacterAction">
<result name="error">/pages/chatQuestion/limitedCharacter.jsp</result>
<result name="success">/pages/chatQuestion/limitedCharacterSuccess.jsp</result>
</action>


</package>


<!-- Add packages here -->

</struts>

第三步 : 创建一个包含textarea和submit按钮的JSP页面 :

这是要添加到limitedCharacter.jsp的代码 :
<%@ taglib prefix="s" uri="/struts-tags" %>

<html>
<head>
<title>Limited Characters in Text Area</title>
<s:head theme="ajax" />
</head>
<body>

<s:form action="characterLimit1" method="POST" validate="true">
<s:textarea name="summary1" label="Brief Summary" rows="6" cols="40"/>
<s:submit value="Save" align="center" />
</s:form>

</body>
</html>

第四步 :　创建一个Action类 :

将这些代码添加到thelimitedCharacterAction.java :

package net.roseindia;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import java.io.PrintStream;
import java.util.List;
import java.util.*;

public class limitedCharacterAction extends ActionSupport{
private String summary1;

public String getSummary1() {
return summary1;
}

public void setSummary1(String summary1) {
this.summary1 = summary1;
}

public String execute() throws Exception{
String summaryText = getSummary1();
long countSummaryText = summaryTextcount(summaryText);
System.out.println("countSummaryText:"+countSummaryText);
if (countSummaryText >0 && countSummaryText < 250){
return SUCCESS;
}
else{
if(getSummary1().equals(""))
addFieldError("summary1","Brief Summary is required.");
if((countSummaryText > 250))
addFieldError("summary1","Brief Summary must be 1 to 250 Charaters");
return ERROR;
}
}

private static long summaryTextcount(String str){
return str.length();
}
}

第五步 : 创建一个JSP包含输入文本的textarea

将这些代码添加到limitedCharacterSuccess.jsp:

<%@ taglib prefix="s" uri="/struts-tags"%>

<html>
<head>
<title>Limited Characters in Text Area</title>

<link href="<s:url value="/css/main.css"/>" rel="stylesheet"
type="text/css"/>
</head>
<body>

<b>Brief Summary: </b><s:property value="summary1" /><br>
</body>

</html>

输出 :