Struts Integer Range Field Validator Example

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:

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:

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

About the Author:

Nam Ha Minh is certified Java programmer (SCJP and SCWCD). He began programming with Java back in the days of Java 1.4 and has been passionate about it ever since. You can connect with him on Facebook and watch his Java videos on YouTube.