Struts Short Range Field Validator Example

The short range field validator in Struts is very similar to the integer one, except it can be used only for a field of short primitive/wrapper type. This validator checks if a short field falls within a certain range. Like other Struts validators, there are two forms of using this validator:

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

NOTES: Attempting to apply the short validator on a field of other types (e.g. long, int, or byte) will result in a runtime java.lang.ClassCastException.

1. Struts Short Range Field Validator XML

Usage:

• Field-validator syntax:
  

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

   

• Plain-validator syntax:
  

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

Parameters:

Struts Short Range Field Validator XML Examples:

• Field-validator example:

   

  <field name="quantity">
  	<field-validator type="short">
  		<param name="min">1</param>
  		<param name="max">10</param>
  		<message>Please enter quantity between ${min} and ${max}</message>
  	</field-validator>
  </field>

   

• Omitting the minimum check:

  <field name="quantity">
  	<field-validator type="short">
  		<param name="max">10</param>
  		<message>Please enter quantity less than ${max}</message>
  	</field-validator>
  </field>

• Using minExpression and maxExpression:
  

  <field name="quantity">
  	<field-validator type="short">
  		<param name="minExpression">${minValue}</param>
  		<param name="maxExpression">${maxValue}</param>
  		<message>Please enter quantity between ${min} and ${max}</message>
  	</field-validator>
  </field> 

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

  public short getMinValue() {
  	return 1;
  }
  
  public short getMaxValue() {
  	return 10;
  }

   

• Plain-validator example:
  

  <validator type="short">
  	<param name="fieldName">quantity</param>
  	<param name="min">1</param>
  	<param name="max">10</param>
  	<message>Oops! Please enter quantity between ${min} and ${max}</message>
  </validator> 

2. Struts @ShortRangeFieldValidator Annotation

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

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

Parameters:

Struts @ShortRangeFieldValidator Annotation Examples:

• Basic field-validator:
  

  @ShortRangeFieldValidator(
  		min = "20", max = "70",
  		message = "Please enter quantity between ${min} and ${max}")
  public void setQuantity(short quantity) {
  	this.quantity = quantity;
  }

   

• Specifying i18n key for the message:
  

  @ShortRangeFieldValidator(
  		min = "20", max = "70",
  		message = "Default message",
  		key = "form.validation.quantity")
  public void setQuantity(short quantity) {
  	this.quantity = quantity;
  }

   

• Plain-validator (annotating the action method):
  

  @ShortRangeFieldValidator(
  		type = ValidatorType.SIMPLE,
  		fieldName = "quantity",
  		min = "20", max = "70",
  		message = "Please enter quantity 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 Integer Range Field Validator Example
• Struts String Length Field Validator Example
• Struts URL Validator Example
• Struts Required Field Validator Example
• Struts Field Expression 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.