Integrating JSR 303 Bean Validation with Oracle ADF 11g

In this post, I will try to show you how we were able to successfully integrate the JSR 303 Bean Validation into our ADF 11g Application built with EJB/JPA. The result is a centralized area to define validation constraints using annotations which can be invoked from any layer of the application.

Below is the screen-shot of a sample edit page created with the JSR 303 Bean Validation:
To apply JSR 303 Bean Validation a project, we need to do the following steps:

1. Download the JSR 303 reference implementation from Hibernate.
2. Add the 5 jar files into your Model project's Libraries and Classpath (Project Properties).
3. Annotate your entities with validation annotations like the sample code snippet below:

   ...
   import javax.validation.constraints.DecimalMax;
   import javax.validation.constraints.Max;
   import javax.validation.constraints.Size;
   ...
   public class Employee implements Serializable {
       @Id
       @Column(name="EMPLOYEE_ID", nullable = false)
       private Long employeeId;
       @Column(name="FIRST_NAME", length = 20)
       @Size(min = 3, max = 20)
       private String firstName;
       @Column(name="LAST_NAME", nullable = false, length = 25)
       @Size(min = 3, max = 20)
       private String lastName;
       @Max(1000000)
       private Double salary;
       @Column(name="COMMISSION_PCT")
       @DecimalMax("1.00")
       private Double commissionPct;
   ...
   

4. Create a utility class that will handle extraction of validation messages like the one below:

   package com.blogspot.soadev.util;
   
   import java.util.Set;
   import javax.validation.ConstraintViolation;
   import javax.validation.Validation;
   import javax.validation.ValidatorFactory;
   
   public class MyUtils {
       public static javax.validation.Validator getValidator() {
   
           ValidatorFactory factory =
               Validation.buildDefaultValidatorFactory();
           return factory.getValidator();
       }
   
       public static String extractConstraintViolationMessages(Set violations) {
           StringBuilder builder = new StringBuilder();
           for (Object obj : violations) {
               if (obj instanceof ConstraintViolation) {
                   builder.append(((ConstraintViolation)obj).getMessage());
                   builder.append("\n");
               }
           }
           return builder.toString();
       }
       //This method returns a set of validation constraint errors
   
       public static Set validateEntity(Object object) {
           javax.validation.Validator validator = getValidator();
           return validator.validate(object);
       }
       // returns null if no violation
   
       public static String getEntityValidationErrorMsg(Object object) {
           Set violations = validateEntity(object);
           if (violations.size() > 0) {
               return extractConstraintViolationMessages(violations);
           }
           return null;
       }
   }
   

5. In the ViewController project, create the following class that implements javax.faces.validator.Validator.

   package com.blogspot.soadev.view.validator;
   import com.blogspot.soadev.util.MyUtils;
   import com.blogspot.soadev.view.util.JSFUtils;
   import java.util.Set;
   import javax.el.ELException;
   import javax.faces.FacesException;
   import javax.faces.application.FacesMessage;
   import javax.faces.component.EditableValueHolder;
   import javax.faces.component.UIComponent;
   import javax.faces.context.FacesContext;
   import javax.faces.validator.Validator;
   import javax.faces.validator.ValidatorException;
   import javax.validation.ConstraintViolation;
   import javax.validation.Validation;
   
   public class BeanValidator implements Validator {
       private static final String DOT_REGEX = "[.]";
       private static final String BINDINGS = "bindings";
       private static final String INPUT_VALUE = "inputValue";
       private static final String NAME = "name";
       private static final String EMPTY_STRING = "";
       private static final String END_CURLY_BRACKET = "}";
       private static final String DATA_PROVIDER = "currentRow.dataProvider";
       private static final String DOT = ".";
   
       public BeanValidator() {
           super();
       }
   
       public void validate(FacesContext facesContext, UIComponent component,
                            Object object) throws ValidatorException {
           if (component instanceof EditableValueHolder) {
               // Validate input component
               EditableValueHolder input = (EditableValueHolder)component;
               
               try {
                   String expression =
                       component.getValueExpression("value").getExpressionString();
                   if (null != expression) {
                       Set<ConstraintViolation<Object>> constraintViolations =
                           validateValue(object, expression);
   
                       if (constraintViolations.size() > 0) {
                           input.setValid(false);
                           // send all validation messages.
                           String msg =
                               MyUtils.extractConstraintViolationMessages(constraintViolations);
                           FacesMessage fm =
                               new FacesMessage(FacesMessage.SEVERITY_ERROR, msg,
                                                null);
                           throw new ValidatorException(fm);
                       }
                   }
               } catch (ELException e) {
                   throw new FacesException(e);
               }
           }
   
       }
   
       private Set<ConstraintViolation<Object>> validateValue(Object object,
                                                                                String expression) {
           Object targetObject = getTargetObject(expression);
           String property = getProperty(expression);
           javax.validation.Validator validator =
               Validation.buildDefaultValidatorFactory().getValidator();
           Set constraintViolations =
               validator.validateValue(targetObject.getClass(), property, object);
           return constraintViolations;
       }
       public String getProperty(String expression){
           if (expression.contains(BINDINGS) && expression.contains(INPUT_VALUE)){
              expression =
                   expression.replaceFirst(INPUT_VALUE, NAME);       
               return JSFUtils.resolveExpression(expression).toString();
           }
           String [] tokens = expression.split(DOT_REGEX);
           String result  = tokens[tokens.length-1];
           result = result.replaceAll(END_CURLY_BRACKET, EMPTY_STRING);
           return result;
       }
       
       public Object getTargetObject(String expression){
           if (expression.contains(BINDINGS) && expression.contains(INPUT_VALUE)){
               expression =
                   expression.replaceFirst(INPUT_VALUE, DATA_PROVIDER);
               return JSFUtils.resolveExpression(expression);
           }
               String [] tokens = expression.split(DOT_REGEX);
               StringBuilder builder = new StringBuilder(tokens[0]);
               for (int i = 1; i < tokens.length - 1; i++){
                   builder.append(DOT);
                   builder.append(tokens[i]);
               }
               builder.append(END_CURLY_BRACKET);
               return JSFUtils.resolveExpression(builder.toString());        
       }
   }
   

6. Add the JSR303BeanValidator class above to the list of validators in faces-config.xml
7. Apply the JSR303BeanValidator to your input components in ADF Faces.

   <af:inputText value="#{bindings.firstName.inputValue}"
                                       label="#{bindings.firstName.hints.label}"
                                       required="#{bindings.firstName.hints.mandatory}"
                                       columns="#{bindings.firstName.hints.displayWidth}"
                                       maximumLength="#{bindings.firstName.hints.precision}"
                                       shortDesc="#{bindings.firstName.hints.tooltip}"
                                       id="it2" autoSubmit="true">
                           <f:validator validatorId="JSR303BeanValidator"/>
                         </af:inputText>
                         <af:inputText value="#{bindings.lastName.inputValue}"
                                       label="#{bindings.lastName.hints.label}"
                                       required="#{bindings.lastName.hints.mandatory}"
                                       columns="#{bindings.lastName.hints.displayWidth}"
                                       maximumLength="#{bindings.lastName.hints.precision}"
                                       shortDesc="#{bindings.lastName.hints.tooltip}"
                                       id="it4" autoSubmit="true">
                           <f:validator validatorId="JSR303BeanValidator"/>
                         </af:inputText>
                         <af:inputText value="#{bindings.salary.inputValue}"
                                       label="#{bindings.salary.hints.label}"
                                       required="#{bindings.salary.hints.mandatory}"
                                       columns="#{bindings.salary.hints.displayWidth}"
                                       maximumLength="#{bindings.salary.hints.precision}"
                                       shortDesc="#{bindings.salary.hints.tooltip}"
                                       id="it3" autoSubmit="true">
                           <f:validator validatorId="JSR303BeanValidator"/>
                           <af:convertNumber groupingUsed="false"
                                             pattern="#{bindings.salary.format}"/>
                         </af:inputText>
   

8. Run your project and try to input invalid values. To display the validation error messages after you tab out of a component, ensure to set the "AutoSubmit" attribute of the component to true.

To know more about JSR 303, click here and here.

Related Posts

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