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15. Example 12 – Various Conversions and Validations

The new application features the entry of various elements with Struts validators:

  • in [1], the input form
  • in [2], the input confirmation

The application works similarly to the previous ones, so we will only comment on the points that differ.

15.1. The NetBeans project

The NetBeans project is as follows:

  • in [1], the application views
  • [Accueil.jsp]: the home page
  • [FormDivers.jsp]: the input form
  • [ConfirmationFormDivers.jsp]: the confirmation page
  • in [2], the message file [messages.properties] and the main Struts configuration file
  • in [3]:
  • [FormDivers.java]: the action that displays and processes the form
  • [FormDivers-validation.xml]: the validation rules for the [FormDivers] action. This file delegates these validations to the model.
  • [FormDiversModel]: the model for the [FormDivers] action
  • [FormDiversModel-validation.xml]: the model's validation rules
  • [FormDiversModel.properties]: the model's message file
  • [example.xml]: secondary Struts configuration file

15.2. Project configuration

The project is primarily configured by the following [example.xml] file:


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
        "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
  <package name="example" namespace="/example" extends="struts-default">
    <action name="Home">
      <result name="success">/example/Home.jsp</result>
    </action>
    <action name="FormDivers" class="example.FormDivers">
      <result name="input">/example/FormDivers.jsp</result>
      <result name="cancel" type="redirect">/example/Home.jsp</result>
      <result name="success">/example/ConfirmationFormDivers.jsp</result>
    </action>
  </package>
</struts>

It is similar to the one studied in previous versions.

15.3. Message files

The [messages.properties] file is as follows:


Home.title=Home
Home.message=Struts 2 - Conversions and validations
Home.FormMisc=Miscellaneous inputs (email, URL, string with character count validation)
Form.title=Conversions and validations
FormMisc.message=Struts 2 - Miscellaneous conversions and validations
Form.submitText=Validate
Form.cancelText=Cancel
Form.clearModel=Clear model
Confirmation.title=Confirmation
Confirmation.message=Confirmation of entered values
Confirmation.field=field
Confirmation.value=value
Confirmation.link=Test form
xwork.default.invalid.fieldvalue=Invalid value for the "{0}" field.

The [FormDiversModel.properties] file is as follows:


email.prompt=1-Enter an email address (x@y.z)
email.error=Invalid format
url.prompt=2-Enter a URL (http://www.ibm.com)
url.error=Invalid format
string.prompt=3-Enter a 5-character string
string.error=Invalid format

15.4. The input form

The [FormDivers.jsp] view is as follows:


<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
  <head>
    <title><s:text name="Form.title"/></title>
    <s:head/>
  </head>

  <body background="<s:url value="/resources/standard.jpg"/>">
    <h2><s:text name="FormDivers.message"/></h2>
    <s:form name="form" action="FormDivers">
      <s:textfield name="email" key="email.prompt" size="30"/>
      <s:textfield name="url1" key="url.prompt" size="30"/>
      <s:textfield name="chaine" key="chaine.prompt" size="10"/>
      <s:submit key="Form.submitText" method="execute"/>
    </s:form>
    <br/>
    <s:url id="url" action="FormDivers" method="cancel"/>
    <s:a href="%{url}"><s:text name="Form.cancelText"/></s:a>
      <br/>
    <s:url id="url" action="FormDivers" method="clearModel"/>
    <s:a href="%{url}"><s:text name="Form.clearModel"/></s:a>
  </body>
</html>

Lines 12 through 14 are the three input fields.

15.5. The confirmation view

The confirmation view [ConfirmationFormDivers.jsp] is as follows:


<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
  <head>
    <title><s:text name="Confirmation.title"/></title>
    <s:head/>
  </head>

  <body background="<s:url value="/resources/standard.jpg"/>">
    <h2><s:text name="Confirmation.message"/></h2>
    <table border="1">
      <tr>
        <th><s:text name="Confirmation.field"/></th>
        <th><s:text name="Confirmation.value"/></th>
      </tr>
      <tr>
        <td><s:text name="email.prompt"/></td>
        <td><s:text name="email"/></td>
      </tr>
      <tr>
        <td><s:text name="url.prompt"/></td>
        <td><s:text name="url1"/></td>
      </tr>
      <tr>
        <td><s:text name="chaine.prompt"/></td>
        <td><s:text name="channel"/></td>
      </tr>
     </table>
    <br/>
    <s:url id="url" action="FormDivers!input"/>
    <s:a href="%{url}"><s:text name="Confirmation.link"/></s:a>
  </body>
</html>

15.6. The [FormDiversModel] template

The input fields from the [FormDivers.jsp] form are injected into the following [FormDiversModel] template:


package example;

public class FormDiversModel {

  // constructor without parameters
  public FormDiversModel() {
  }
  
  // fields
  private String email;
  private String url1;
  private String string;

    // clear model
  public void clearModel() {
    email = null;
    url1 = null;
    string = null;
  }

  // getters and setters
   ...
}

15.7. Model validation

Model validation is controlled by two files: [FormDivers-validation.xml] and [FormDiversModel-validation.xml].

The [FormDivers-validation.xml] file delegates validations to the following [FormDiversModel-validation.xml] file:


<!--
<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//
EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">
-->
<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//
EN" "http://localhost:8084/exemple-10/example/xwork-validator-1.0.2.dtd">

<validators>
  <field name="model" >
    <field-validator type="visitor">
      <param name="appendPrefix">false</param>
      <message/>
    </field-validator>
  </field>
</validators>

We have already encountered this file.

The [FormDateModel-validation.xml] file contains the following validation rules:


<!--
<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//
EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">
-->

<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//
EN" "http://localhost:8084/exemple-12/example/xwork-validator-1.0.2.dtd">

<validators>

  <field name="email" >
    <field-validator type="requiredstring" short-circuit="true">
      <message key="email.error"/>
    </field-validator>
    <field-validator type="email" short-circuit="true">
      <message key="email.error"/>
    </field-validator>
  </field>

  <field name="url1" >
    <field-validator type="requiredstring" short-circuit="true">
      <message key="url.error"/>
    </field-validator>
    <field-validator type="url" short-circuit="true">
      <message key="url.error"/>
    </field-validator>
  </field>

  <field name="string">
    <field-validator type="requiredstring" short-circuit="true">
      <message key="string.error"/>
    </field-validator>
    <field-validator type="stringlength" short-circuit="true">
      <param name="minLength">5</param>
      <param name="maxLength">5</param>
      <message key="chaine.error"/>
    </field-validator>
  </field>

</validators>
  • lines 11–18: check the validity of the email field
  • lines 15-17: verify that the email string is a valid email address
  • lines 20-27: verify the validity of the url1 field
  • lines 24–26: verify that the url1 string is a valid URL
  • lines 29-38: check the validity of the chaine field
  • lines 33-37: verify that the string chaine is exactly 5 characters long.

15.8. The [FormDivers] action

The [FormDivers] action is as follows:


package example;

import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
import java.util.Map;
import org.apache.struts2.interceptor.SessionAware;
import org.apache.struts2.interceptor.validation.SkipValidation;

public class FormDivers extends ActionSupport implements ModelDriven, SessionAware {

  // Constructor without parameters
  public FormDivers() {
  }

  // action model
  public Object getModel() {
    if (session.get("model") == null) {
      session.put("model", new FormDiversModel());
    }
    return session.get("model");
  }

  @SkipValidation
  public String clearModel() {
    // Clear the model
    ((FormDiversModel) getModel()).clearModel();
    // result
    return INPUT;
  }

  public String cancel() {
    // clear the model
    ((FormDiversModel) getModel()).clearModel();
    // result
    return "cancel";
  }

  // SessionAware
  Map<String, Object> session;

  public void setSession(Map<String, Object> session) {
    this.session = session;
  }
}

The [FormDivers] action is built on the same model as the actions discussed previously. Here, there is simply no validate method to complement the validation performed by the [FormDiversModel-validation.xml] file.

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This tutorial written by Serge Tahé is made available to the public under the terms of the Creative Commons Attribution – Non-Commercial – ShareAlike 3.0 Unported.