hibernate search & bean validation

Copyright © Emmanuel Bernard – License Creative Commons 2.0 France

Ch’ti JUG

Hibernate Search et Bean Validation

Emmanuel Bernard

21 septembre 2009


Ch’ti JUG Emmanuel Bernard

Hibernate Search in Action blog.emmanuelbernard.com twitter.com/emmanuelbernard

lescastcodeurs.com


Ch’ti JUG

Hibernate Core

Emmanuel BernardJBoss by Red Hat


Ch’ti JUG Performance

Transactional write behind sophisticated snapshot comparison load associated objects (join, subselect,

batch) batch changes / bulk operations lazy collections / objects prepared statements pre-compiled queries smart merge ...


Ch’ti JUG Flexibility

Override any SQL DDL generation optional stored procedures statistics used named queries stateless session Bulk HQL Database portability


Ch’ti JUG Tips

Use conversation scoped persistence contexts aka first level cache

do not 2nd level cache for everything• reference data

set everything as lazy and use queries

Stop maintaining your home-grown ORM


Ch’ti JUG

JSR-303 - Bean Validation



Ch’ti JUG

Enable declarative validation in your applications

Constrain Once, Validate Anywhere


Ch’ti JUG Constraints

Constraint• restriction on a bean, field or property• not null, between 10 and 45, valid email...

How is that useful• give feedback to the user• ensure that a service will behave correctly

• define service range of usability

• avoid adding crap to the database• unless you like fixing the data manually


Ch’ti JUG Constraints in the Java Ecosystem

Where should they be applied

How many model do I have?• 1

DatabaseClient Side

Java

Data Access Layer

Business Layer

Presentation Layer


Ch’ti JUG What is the solution?

Uniform way to express a constraint• everybody speaks the same language• based on the domain model (JavaBeans™)

Standard way to validate constraints• one runtime engine• same validation implementations shared

Bridge for constraints out of Java™ land• API to access the constraint repository


Ch’ti JUG Declare a constraintpublic class Address { @NotNull @Size(max=30, message="longer than {max} characters") private String street1; ... @NotNull @Valid private Country country;

}

public class Country { @NotNull @Size(max=30) private String name; ...

}


Ch’ti JUG Groups

Subset of constraints

Partial validation• screen of a wizard UI

Constraints applied in a given use case Order constraint validations

• which depends on other validations• when a constraint is resource/time intensive


Ch’ti JUG

interface Billable {}

interface BuyInOneClick extends Billable, Default {}

class User { @NotNull(groups=BuyInOneClick.class) PaymentMethod getDefaultCreditCard() {...}

@NotNull //Default group String getUserName() {...}}

@GroupSequence(sequence={Default.class, Heavy.class})interface Complete {}


Ch’ti JUG Create your own constraint

Annotations with expressive names List of ConstraintValidators Constraint composition


Ch’ti JUG

@Constraint(validatedBy={ SizeValidatorForCollections.class), SizeValidatorForString.class } )public @interface Size { String message() default "{constraint.size}"; Class<?>[] groups() default {}; Class<? extends ConstraintPayload> payload() default {};

//custom attributes int min() default 0; int max() default Integer.MAX_VALUE;}


Ch’ti JUG

public class SizeValidatorForString implements ConstraintValidator<Size, String> {

public void initialize(Size annotation) {}

public boolean isValid(String value, ConstraintValidatorContext context) {}}


Ch’ti JUG Composition

Reuse constraints Expose meta-informations

@NotNull @Size(min=5, max=5)@Constraint(validatedBy=FrenchZipCodeValidator.class)public @interface FrenchZipCode { String message() default "{constraint.frenchzipcode}"; Class<?>[] groups() default {}; Class<? extends ConstraintPayload>[] payload() default {};}


Ch’ti JUG

Integration - tools - plain SE - EE 6


Ch’ti JUG

extensible support multiple implementations type-safe can override some attributes contextually

XML configuration optional• META-INF/validation.xml

Bootstrap API


Ch’ti JUG

ValidatorFactory vf = Validation.buildDefaultValidatorFactory();

ValidatorFactory vf = Validation.byDefaultProvider() .configure() .messageInterpolator( containerMI ) .traversableResolver( jpaTR ) .constraintValidatorFactory( webBeansDI ) .buildValidatorFactory();

ValidatorFactory vf = Validation .byProvider(HibernateValidationProvider.class) .configure() .messageInterpolator( containerMI ) .failFast() .enableLegacyConstraints() .buildValidatorFactory();


Ch’ti JUG Message

Can be externalized Internationalization Interpolate constraint parameters

• must be shorter than {min}

Custom MessageInterpolator strategy• Useful for application frameworks• Contextual data• Locale


Ch’ti JUG Manual validation

Get a Validator from a ValidatorFactory

ConstraintViolation• error message / message template• invalid value• context

Set<ConstraintViolation<User>> errors = validator.validate(user);

Set<ConstraintViolation<User>> errors = validator.validate(user, BuyInOneClick.class);


Ch’ti JUG Accessing the metadata

DDL generation, tools, JavaScript generators

Metadata API

Shines with:• composition• built-in annotations

BeanDescriptor - validator.getConstraintsForClass(User.class)PropertyDescriptor - beanDescr.getConstrainedProperties()ConstraintDescriptor - descr.getConstraintDescriptors() - constrDescr.getComposingConstraints()


Ch’ti JUG JSF 2 integration

Zero conf Validate input components

• find property via Expression Language• call Bean Validation on input value• return localized error messages• use JSF user Locale

• custom MessageInterpolator


Ch’ti JUG Java Persistence 2

On entity change• validation• can select the groups validated

Make use of a custom TraversableResolver• do not traverse associations


Ch’ti JUG Java EE 6

Validator as an injectable resource

@Resource Validator validator;//or@Resource ValidatorFactory vf;


Ch’ti JUG Bean Validation

Status Todo

• Well... nothing

Give us feedback!


Ch’ti JUG Hibernate Validator 4

Bean Validation is in proposed final draft• RI available

Road Map• working on the TCK• backward compatible with legacy Hibernate

Validator usage• some cool ideas out of the spec scope

License• ASL 2.0


Ch’ti JUG Questions?

JCP.org • http://jcp.org/en/jsr/detail?id=303• http://people.redhat.com/~ebernard/

validation

http://in.relation.to• Search for ‘Bean Validation’

Hibernate Validator• http://validator.hibernate.org

http://forum.hibernate.org/viewforum.php?f=26

http://jcp.org/en/jsr/detail?id=303

http://jcp.org/en/jsr/detail?id=303

http://people.redhat.com/~ebernard/validation




http://in.relation.to


http://validator.hibernate.org

http://validator.hibernate.org






Ch’ti JUG

Hibernate SearchFull-text search for Hibernate Apps



Ch’ti JUG

Understand what full-text search does for you

Understand the magic sauce: analyzers Full-text search and applications: how does

it fit? Bring the Wow! effect to existing

applications


Ch’ti JUG

Searching is asking a question

Different ways to answer• Categorize data up-front• Offer a detailed search screen• Offer a simple search box

What is searching?


Ch’ti JUGHuman search

in a relational world where?

• which columns, which tables

column != word• wildcard queries?

did you say “car” or “vehicle”? cympausium or simposyum? Order results by relevance

How to do that in SQL?


Ch’ti JUG Full Text Search

Search by word Dedicated index

• inverted indices (word frequency, position)

Very efficient

Full text products:• embedded in the database engine• black box / appliance• library embeddable like Lucene


Ch’ti JUG Some of the interesting problems

bring the “best” document first recover from typos recover from faulty orthography find from words with the same meaning find words from the same family find an exact phrase find similar documents


Ch’ti JUG Find by relevance

Best results first• very human sensitive

Prioritize some fields over others The more matches, the better

• for a given key word per document• for a given document the amount of matching

key words

Similarity algorithm


Ch’ti JUG Extracting the quintessence

Word: Atomic information

Analyzer• Chunk / tokenize the text into individual words• Apply filters

• remove common words• lower case

One tokenizer Some filters


Ch’ti JUGApproximation

Recover from typos and other approximations

Fuzzy search• query time operation• Levenshtein distance (edit distance)

Hibernate

Hibrenate


Ch’ti JUG

hibernate

hib ibe ber ern nat ate

ybe ber ern nat

ybernat

Index

Query

n-gram• cut the word in parts of n characters• index each piece

Indexing + query time strategy• use a TokenFilter


Ch’ti JUG Demo


Ch’ti JUG Phonetic search

Is it “jiroscop” or “gyroscope”• not so useful in daily life

Several phonetic algorithms• Soundex• Metaphone (JRSKP)• mostly for latin languages

index the phonetic equivalent of a word



Ch’ti JUG Synonyms

I like to drive my auto around

I love to drive my banger around

I cherish to drive my car around

I love to drive my auto around

cherish

love

like banger

auto

car

jalopy

Based on a synonym dictionary index a reference word in the index



Ch’ti JUG Words from the same family

love, lover, loved, loving Brutal force

• index all variations of a word

Stemming• Porter algorithm for English• Snowball Stemmer for most Indo-European

languages



Ch’ti JUG What’s the catch

Lucene is quite low level Integration into an application model Index synchronization Object model conversion Programmatic mismatch


Ch’ti JUGIntegration into a Java SE / EE

app Hibernate Search bridges

• Hibernate Core and Java Persistence• JBoss Cache & Infinispan (More to come)• Apache Lucene

Transparent index synchronization• event based

Metadata driven conversion• annotation based

Unified programmatic model• API• semantic


Ch’ti JUG More on Hibernate Search

Asynchronous clustering (JMS, JGroups) Projection Filters Index sharding Custom DirectoryProvider (eg. JBoss

Cache, Infinispan based) JBoss Cache is full text searchable Native Lucene access


Ch’ti JUG Asynchronous cluster

Search local / change sent to master Asynchronous indexing (delay) No front end extra cost / good scalability

DatabaseHibernate +

Hibernate Search

JMS queue

Lucene Directory(Index)Master

Hibernate +

Hibernate SearchProcessIndex update

Index update order

Lucene Directory(Index)Copy

Search request

Copy

Slave

Master


Ch’ti JUG

49

Summary

Search for humans Full text tackles those problems

• relevance• (human) fault tolerance• stemming and synonyms• incremental search

Barrier of entry has lowered: Go for it!• POJO based approach• infrastructural code tackled by frameworks• unified programmatic model


Ch’ti JUG Questions?

http://search.hibernate.org http://lucene.apache.org Hibernate Search in Action

• Manning

http://in.relation.to http://blog.emmanuelbernard.com

http://search.hibernate.org

http://search.hibernate.org

http://lucene.apache.org

http://lucene.apache.org



http://blog.emmanuelbernard.com

http://blog.emmanuelbernard.com


Ch’ti JUG Licence

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Ch’ti JUG Buffet

Merci pour votre attention

Merci à Norsys pour son sponsoring

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hibernate search & bean validation

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class user