Table of contents

Introduction

Requiredstring Validator

Example of Requiredstring Validator 🧑‍💻

3.1.

1️⃣Create index.jsp for Input

3.2.

2️⃣Create the Action Class

3.3.

3️⃣Create the Approval Record

3.4.

4️⃣Create struts.xml

3.5.

5️⃣Create View Part

3.6.

Output

Frequently Asked Questions❓

5.1.

What is a string validator?

5.2.

What is string approval Python?

5.3.

How would you approve a string in Java?

5.4.

How would you approve in Python?

5.5.

How would you approve an ordinary articulation?

Conclusion

Last Updated: Mar 27, 2024

Easy

Requiredstring Validator

Author Adya Tiwari

Introduction

Hey Ninja🥷let us begin with the introduction of the requiredstring validator. So, RequiredStringValidator makes sure that a String field is non-invalid and has a length > 0. (for example, it isn't ""). The trim boundary decides if it will String#trim() the String before playing out the length check. On the off chance that unknown, the String will be managed.

The requiredstring validator indicates that the string can't be invalid or clear. It manages the line by default and then checks, assuming its length is more noteworthy than 0.

Requiredstring Validator

The Struts approval structure gives the necessary string validator to check a String field isn't invalid and not vacant ("").

It accompanies two flavors: 📑

🔹XML: utilizing type="requiredstring" characteristic in <validator> or <field-validator> components.

🔹Comment: utilizing @RequiredStringValidator explanation type to explain setter strategy for the field.

Example of Requiredstring Validator 🧑‍💻

All the file names of their respective codes have been highlighted below for easy access and understanding.

<validators>  
    <!-- Plain-Validator Syntax -->  
    <validator type="requiredstring">  
        <param name="fieldName">username</param>  
        <param name="trim">true</param>  
        <message>username is required</message>  
    </validator>  
     
</validators>  


<validators>  
    <!-- Field-Validator Syntax -->  
    <field name="username">  
          <field-validator type="requiredstring">  
            <param name="trim">true</param>  
            <message>username is required</message>  
       </field-validator>  
    </field>  
 
</validators>

1️⃣Create index.jsp for Input

This jsp page makes a structure utilizing swaggers UI labels. It gets a name, secret phrase, and email id from the client.

Index.jsp

<%@ taglib uri="/struts-tags" prefix="s" %>  
<html>  
<head>  
<STYLE type="text/css">  
.errorMessage{color:red;}  
</STYLE>  
</head>  
<body>  
 
<s:form action="register">  
<s:textfield name="username" label="Username"></s:textfield>  
<s:password name="userpass" label="Password"></s:password>  
<s:submit value="register"></s:submit>  
</s:form>  
 
</body>  
</html>

2️⃣Create the Action Class

This activity class acquires the ActionSupport type and abrogates the execute strategy.

RegisterAction.java

package com.javatpoint;  
 
import com.opensymphony.xwork2.ActionSupport;  
 
public class Register extends ActionSupport{  
private String username,userpass;  
 
public String getUsername() {  
    return username;  
}  
 
public void setUsername(String username) {  
    this.username = username;  
}  
 
public String getUserpass() {  
    return userpass;  
}  
 
public void setUserpass(String userpass) {  
    this.userpass = userpass;  
}  
 
public String execute(){  
    return "success";  
}  
 
}

3️⃣Create the Approval Record

Here, we are utilizing packaged validators to play out the approval.

Register-validation.xml

<?xml version="1.0" encoding="UTF-8"?>  
 
  <!DOCTYPE validators PUBLIC  
        "-//OpenSymphony Group//XWork Validator 1.0.2//EN"  
        "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">  
 
        <validators>  
         
        <field name="username">  
        <field-validator type="requiredstring">  
        <message>Name can't be blank</message>  
        </field-validator>  
        </field>  
         
         
        </validators>

4️⃣Create struts.xml

This xml record characterizes a different outcome by the name input and an interceptor jsonValidatorWorkflowStack.

Struts.xml

<?xml version="1.0" encoding="UTF-8" ?>  
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd">  
<struts>  
 
<package name="default" extends="struts-default">  
<action name="register" class="com.javatpoint.Register">  
<result name="input">index.jsp</result>  
<result>welcome.jsp</result>  
</action>  
 
</package>  
</struts>

5️⃣Create View Part

It is the basic jsp document showing the data of the client.

If credentials or needed information is not entered the user will get the field required message.

Welcome.jsp

<%@ taglib uri="/struts-tags" prefix="s" %>  
 
Welcome,<s:property value="username"/>

Output

Frequently Asked Questions❓

What is a string validator?

String validators are works that permit us to check if a string meets specific standards.

What is string approval Python?

Python has inherent string approval strategies for basic information. It can check if a string is made out of in-order characters, alphanumeric characters, digits, and so on str.isalnum() This technique assumes every one of the characters of a string is alphanumeric (a-z, A-Z, and 0-9).

How would you approve a string in Java?

By utilizing Java's underlying techniques:

🔸Number. parseInt(String)

🔸Float. parseFloat(String)

🔸Twofold. parseDouble(String)

🔸Long. parseLong(String)

🔸new BigInteger(String)

How would you approve in Python?

The approval should be possible in two unique ways: by utilizing a banner variable or by using an attempt or except which the banner variable will be set to bogus at first.

How would you approve an ordinary articulation?

You can utilize ordinary articulations to coordinate and approve clients' text in cfinput and cftextinput labels.

Conclusion

In this article, we have learnt that RequiredStringValidator makes sure that a String field is non-invalid and has a length > 0. (for example, it isn't ""). The trim boundary decides if it will String#trim() the String before playing out the length check. On the off chance that unknown, the String will be managed. The Struts approval structure gives the necessary string validator to check a String field isn't invalid and not vacant ("").

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