The integer range field validator in Struts is used to check if an integer field falls within a specified range. Like other Struts validators, there are two forms of using this validator:

• • XML: using type=”int” attribute in <validator> or <field-validator> elements.
  • Annotation: using @IntRangeFieldValidator annotation type before field’s setter method or action method (plain-validator).

 

1. Struts Integer Range Field Validator XML

Usage:

• Field-validator syntax:
  

  <field name="fieldName">
  	<field-validator type="int">
  		<param name="param name">param value</param>
  		<message>validation error message</message>
  	</field-validator>
  </field>

   

• Plain-validator syntax:
  

  <validator type="int">
  		<param name="param name">param value</param>
  		<message>validation error message</message>
  </validator> 

 

Parameters:

Parameter name	Required	Description
fieldName		Name of the field (required if using plain validator syntax).
min	No	The minimum value to check. It won’t be checked if omitted.
max	No	The maximum value to check. It won’t be checked if omitted.
parse	No	Boolean value. If set to true, evaluate the minExpressionand maxExpression to find min/max.
minExpression	No	Expression to calculate the minimum value. It won’t be evaluated if omitted.
maxExpression	No	Expression to calculate the maximum value. It won’t be evaluated if omitted.

 

Struts Integer Range Field XML Examples:

• Field-validator example:

  <field name="myAge">
  	<field-validator type="int">
  		<param name="min">18</param>
  		<param name="max">25</param>
  		<message>Your age must be between ${min} and ${max}</message>
  	</field-validator>
  </field>

• Omitting the minimum check:

  <field name="myAge">
  	<field-validator type="int">
  		<param name="max">40</param>
  		<message>Your age must below ${max}</message>
  	</field-validator>
  </field>

• Using minExpression and maxExpression:
  

  <field name="myAge">
  	<field-validator type="int">
  		<param name="minExpression">${minValue}</param>
  		<param name="maxExpression">${maxValue}</param>
  		<message>Your age must be between ${min} and ${max}</message>
  	</field-validator>
  </field> 

  In this case, we have to implement two methods getMinValue() and getMaxValue() in the action class as follows:

  public int getMinValue() {
  	return 20;
  }
  
  public int getMaxValue() {
  	return 40;
  }

   

• Plain-validator example:
  

  <validator type="int">
  	<param name="fieldName">myAge</param>
  	<param name="min">18</param>
  	<param name="max">25</param>
  	<message>Your age must be between ${min} and ${max}</message>
  </validator> 

 

2. Struts @IntRangeFieldValidator Annotation

Usage: Put the @IntRangeFieldValidatorannotation before the setter method or action method (in case of using plain-validator) in the following form:

@IntRangeFieldValidator(param1 = "param 1 value", param2 = "param 2 value", ...)

Parameters:

Parameter name	Required	Default value	Description
message	Yes		validation error message.
key	No		i18n key for validation error message.
messageParams	No		Additional parameters to customize the message.
fieldName	No		Specifies field name in case this validator type is plain-validator.
shortCircuit	No	false	Whether this validator is short circuit.
type	No	ValidatorType.FIELD	type of the validator: field-validator (FIELD) or plain-validator (SIMPLE).
min	No		The minimum value to check.
minExpression	No		OGNL expression used to calculate the minimum value.
max	No		The maximum value to check
maxExpression	No		OGNL expression used to calculate the maximum value.
parse	No	false	Whether to evaluate the minExpressionand maxExpression to find min/max.

 

Struts @IntRangeFieldValidator Annotation Examples:

• Basic field-validator:
  

  @IntRangeFieldValidator(min = "18", max = "25",
  		message = "Your age must be between ${min} and ${max}")
  public void setMyAge(int myAge) {
  	this.myAge = myAge;
  }

  
  
  
   

• Specifying i18n key for the message:
  

  @IntRangeFieldValidator(min = "18", max = "25",
  		message = "Default message",
  		key = "form.validation.age")
  public void setMyAge(int myAge) {
  	this.myAge = myAge;
  }

   

• Plain-validator (annotating the action method):
  

  @IntRangeFieldValidator(
  		type = ValidatorType.SIMPLE,
  		fieldName = "myAge",
  		min = "18", max = "25",
  		message = "Your age must be between ${min} and ${max}")
  public String execute() {
  	return SUCCESS;
  } 

 

Related Struts Form Validation Tutorials:

• Struts Form Handling Tutorial
• Struts Form Validation Tutorial
• Struts Date Range Field Validator Example
• Struts Double Range Field Validator Example
• Struts Short Range Field Validator Example
• Struts String Length Field Validator Example

 

Other Struts Tutorials:

• Introduction to Struts 2 framework
• Struts beginner tutorial (Eclipse + Tomcat + XML)
• Struts Beginner Tutorial with Annotations
• Struts beginner tutorial with Convention Plugin (zero-configuration)
• How to handle exceptions in Struts
• Send e-mail with attachments in Struts
• Struts File Upload Tutorial
• Struts - Spring - Hibernate Integration Tutorial