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STRUTS2 Learning Notes (6)-Simple data validation _java

Source: Internet
Author: User
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Data validation is an integral part of project development, user login, password verification needs, of course, the first thing to do is to get the user input content, and then to verify the content, generally read from the database and then check, if the error will display the message, the correct access to the user's main interface.

Here's a simple little example to illustrate the next step:

1, the index of the form

Copy Code code as follows:
<%@ page language= "java" contenttype= "text/html; Charset=utf-8 "
pageencoding= "UTF-8"%>
<%
String path = Request.getcontextpath ();
String basepath = request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path+ "/";
%>
<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "HTTP://WWW.W3.ORG/TR/HTML4/LOOSE.DTD" >
<meta http-equiv= "Content-type" content= "text/html; Charset=utf-8 ">
<base href= "<%=basepath%>"/>
<title>insert title here</title>
<body>
<form action= "User/user!check" method= "POST" >
Name: <input type= "text" name= "User.Name" ></input>
<br/>
Age: <input type= "text" name= "User.age" ></input>
<br/>
<input type= "Submit" value= "submitted"/>
</form>
</body>

The commit will have two variables--user.name and user.age uploaded to the server, and then call the corresponding action in struts.xml file configuration

2, Struts.xml Configuration

Copy Code code as follows:
<?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>
<constant name= "Struts.devmode" value= "true"/>
<package name= "front" namespace= "/user" extends= "Struts-default" >

<action name= "user" class= "com.myservice.web.UserAction" >
<result>/success.jsp</result>
<result name= "Error" >/error.jsp</result>
</action>
</package>
</struts>

Obviously-calling Success.jsp,error when success is returned calls Error.jsp

3, action in the Check method content

Copy Code code as follows:
Public String Check () {
System.out.println ("Name=" +user.getname ());
System.out.println ("age=" +user.getage ());
if (User.getname (). Equals ("admin") &&user.getage () ==20) {
return SUCCESS;
}else{
This.addfielderror ("name", "Name is Error");
This.addfielderror ("name", "name is too long");
return ERROR;
}
}

Here we call the Addfielderror method

4, error.jsp page

Copy Code code as follows:
<%@ page language= "java" contenttype= "text/html; Charset=utf-8 "
pageencoding= "UTF-8"%>
<% @taglib uri= "/struts-tags" prefix= "s"%>
<! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "HTTP://WWW.W3.ORG/TR/HTML4/LOOSE.DTD" >
<meta http-equiv= "Content-type" content= "text/html; Charset=utf-8 ">
<title>insert title here</title>
<body>
<s:property value= "errors.name[0]"/>
<br>
<s:property value= "errors.name[1]"/>
<s:debug></s:debug>
</body>

The third line inside is a description of the tag library that added the Struts2, and begins with S.

and the fourth and sixth lines are the focus, errors.name[0] corresponds to the name is error,errors.name[1 that we put into the Addfielderror method in 3, which is clearly the name is too Long The third line is debug information.

The entire effect is finally displayed as:

The above is a simple data Struts2 in all the content, I hope to give you a reference, but also hope that we support the cloud habitat community.

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Related Keywords:
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