How To Write A Validator In Java 1.1.1

Transcription

1 Bean Validation 1.1 What's cooking? Gunnar Morling JBoss, by Red Hat

2 Bean Validation 1.1 JSR 349 Final Approval Ballot nächste Woche! Vollständig offen Issue-Tracker Mailingliste GitHub: Spezifikation Referenzimplementierung TCK Website Bean Validation 1.1 What's cooking? 2/13

3 Dependency Injection Dependency Injection via CDI ConstraintValidator-Implementierungen public class PastValidator implements ConstraintValidator<Past, Date> private TimeService timeservice; public void initialize(past constraintannotation) { public boolean isvalid(date date, ConstraintValidatorContext context) { if ( date == null ) { return true; return date.before( timeservice.getcurrenttime() ); MessageInterpolator, TraversableResolver, ConstraintValidatorFactory etc Bean Validation 1.1 What's cooking? 3/13

4 Methodenvalidierung (I) Validierung von Methodenparametern und -rückgabewerten beim Aufruf Erfordert Interceptor, AOP, Proxy etc Bean Validation 1.1 What's cooking? 4/13

5 Methodenvalidierung (II) Parameterprüfung old school /** * Places an order. * customercode Must not be null and between 3 and 20 characters. item Must not be null. quantity Must be larger or equal than 1. */ public void placeorder(string customercode, Item item, int quantity) { validatecustomercode(customercode); if(item == null) throw new IllegalArgumentException(); if(quantity < 1) throw new IllegalArgumentException(); //Actual business logic... Nachteile Manuelle Prüfung Redundanz Schnell uneinheitlich Bean Validation 1.1 What's cooking? 5/13

6 Methodenvalidierung (III) Parameterprüfung Bean Validation way public void max=20) String Item int quantity) { Vorteile Validierung einheitlich als Aspekt implementiert Constraints Teil der JavaDoc Programming by Contract Aktiv per Default für CDI Beans und JAX-RS Resourcen Bean Validation 1.1 What's cooking? 6/13

7 Methodenvalidierung (IV) Objektgraphen public max=20) Item int quantity) { // Bean Validation 1.1 What's cooking? 7/13

8 Methodenvalidierung (IV) Objektgraphen public max=20) Item int quantity) { @Valid public max=20) Item int quantity) { // Bean Validation 1.1 What's cooking? 7/13

9 Methodenvalidierung (V) OrderDao orderdao) { // Bean Validation 1.1 What's cooking? 8/13

10 Methodenvalidierung (V) OrderDao orderdao) { //... Cross-parameter public void resetpassword(@notnull passwordconfirmation) = ValidationTarget.PARAMETERS) public class PasswordsMatchValidator implements ConstraintValidator<PasswordsMatch, Object[]> public void initialize(passwordsmatch constraintannotation) public boolean isvalid(object[] value, ConstraintValidatorContext context) { return value[0].equals(value[1]); Bean Validation 1.1 What's cooking? 8/13

11 EL-Ausdrücke in Fehlermeldungen (I) Dynamische Fehlermeldungen mittels Unified EL (JSR 341) public class Foo inclusive=true) private BigDecimal number; ValidationMessages.properties: javax.validation.constraints.decimalmax.message = must be less than ${inclusive == true? 'or equal to ' : ''{value Bean Validation 1.1 What's cooking? 9/13

12 EL-Ausdrücke in Fehlermeldungen (II) Ausgabe des validierten Werts public class Shop minage=18, message="user must at least be ${minage, but is ${validatedvalue.age." ) private User user; // Bean Validation 1.1 What's cooking? 10/13

13 EL-Ausdrücke in Fehlermeldungen (II) Ausgabe des validierten Werts public class Shop minage=18, message="user must at least be ${minage, but is ${validatedvalue.age." ) private User user; //... Formatierung mit Formatter-Object public class Bar value=100, message="value ${formatter.format('%1$.2f', validatedvalue) is too small" ) private double number = d; // ==> "Value is too small" Bean Validation 1.1 What's cooking? 10/13

14 Gruppenkonvertierung zur Validierung von Objektgraphen public class Address must not be empty") private String street; public class Customer private final Address address = new Address(); Bean Validation 1.1 What's cooking? 11/13

15 Gruppenkonvertierung zur Validierung von Objektgraphen public class Address must not be empty") private String street; public class Customer private final Address address = new Address(); Fehlertext in Abhängigkeit der Rolle eines Objekts? public class Customer private final Address homeaddress = new private final Address officeaddress = new Address(); Bean Validation 1.1 What's cooking? 11/13

16 Gruppenkonvertierung (II) Validierungsgruppen definieren public interface HomeChecks{ public interface zur Konvertierung von Gruppen public class street may not be empty", street may not be empty", groups=officechecks.class) ) private String street; public class to = HomeChecks.class) private Address homeaddress = to = OfficeChecks.class) private Address officeaddress = new Address(); Bean Validation 1.1 What's cooking? 12/13

17 Fragen & Antworten?! Bean Validation 1.1 What's cooking? 13/13

18 Referenzen Alles rund um BV: JSR 349: Bean Validation : Hibernate Validator: Forum zu Hibernate Validator: Hibernate Team Blog: Bean Validation 1.1 What's cooking? 14/13