Edit on GitHub << back to Validation

# Basic Validation

Let’s configure a basic validation workflow, step by step.

## Step 1

Create the input form.

    <html>
    <head>
    	<title>Struts2 Showcase - Validation - Basic</title>
    	<s:head/>
    </head>

    <body>

    <div class="page-header">
    	<h1>Basic validation Example</h1>
    </div>

    <div class="container-fluid">
    	<div class="row">
    		<div class="col-md-12">

    			<p>
    				<b>What is your favorite color?</b>

    			<p/>

    			<s:form method="post">
    				<s:textfield label="Name" name="name"/>
    				<s:textfield label="Age" name="age"/>
    				<s:textfield label="Favorite color" name="answer"/>
    				<s:submit cssClass="btn btn-primary"/>
    			</s:form>
    		</div>
    	</div>
    </div>
    </body>
    </html>

## Step 2

Create the Action class.

    public class QuizAction extends ActionSupport {

    	private static final long serialVersionUID = -7505437345373234225L;

    	String name;
    	int age;
    	String answer;

    	public String getName() {
    		return name;
    	}

    	public void setName(String name) {
    		this.name = name;
    	}

    	public int getAge() {
    		return age;
    	}

    	public void setAge(int age) {
    		this.age = age;
    	}

    	public String getAnswer() {
    		return answer;
    	}

    	public void setAnswer(String answer) {
    		this.answer = answer;
    	}
    }

## Step 3

Create the validators. The `validation.xml` format is either `<ActionClassName>-validation.xml` or `<ActionClassName>-<ActionAliasName>-validation.xml`.

    <!--
        Add the following DOCTYPE declaration as first line of your XXX-validation.xml file:
        <!DOCTYPE validators PUBLIC "-//Apache Struts//XWork Validator 1.0.2//EN" "http://struts.apache.org/dtds/xwork-validator-1.0.2.dtd">
    -->
    <validators>
        <field name="name">
            <field-validator type="requiredstring">
                <message>You must enter a name</message>
            </field-validator>
        </field>
        <field name="age">
            <field-validator type="int">
                <param name="min">13</param>
                <param name="max">19</param>
                <message>Only people ages 13 to 19 may take this quiz</message>
            </field-validator>
        </field>
    </validators>

## Step 4

Make sure there is a result for “input” listed in the struts.xml for when the validation fails:

    <action name="HelloWorld" class="tutorial.HelloWorld">
    <result name="success">/tutorial/createconfirm.jsp</result>
    <result name="error">/tutorial/error.jsp</result>
    <result name="input">/tutorial/create.jsp</result>
    </action>

If you don’t have this, you’ll get a: “No result defined for action xxx.xxx.tutorial.HellowWorld and result input” error.