PersonSpecifications.java

package net.petrikainulainen.spring.datajpa.repository;

import net.petrikainulainen.spring.datajpa.model.Person;
import net.petrikainulainen.spring.datajpa.model.Person_;
import org.springframework.data.jpa.domain.Specification;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;

/**
 * A class which is used to create Specification objects which are used
 * to create JPA criteria queries for person information.
 * @author Petri Kainulainen
 */
public class PersonSpecifications {

    /**
     * Creates a specification used to find persons whose last name begins with
     * the given search term. This search is case insensitive.
     * @param searchTerm
     * @return
     */
    public static Specification<Person> lastNameIsLike(final String searchTerm) {
        
        return new Specification<Person>() {
            @Override
            public Predicate toPredicate(Root<Person> personRoot, CriteriaQuery<?> query, CriteriaBuilder cb) {
                String likePattern = getLikePattern(searchTerm);
                return cb.like(cb.lower(personRoot.<String>get(Person_.lastName)), likePattern);
            }
            
            private String getLikePattern(final String searchTerm) {
                StringBuilder pattern = new StringBuilder();
                pattern.append(searchTerm.toLowerCase());
                pattern.append("%");
                return pattern.toString();
            }
        };
    }
}