Session Beans

In JumpStart, the business logic is in Java EE Session Beans, such as PersonFinderService and PersonManagerService.

Here we've used PersonFinderService to find entity Person with id = 1. The @EJB annotation is explained in the next example.
Id
1
Version
34
First Name
aa65
Last Name
b
Region
West Coast
Start Date
Dec 10, 2018
For those of you who do not want to use Session Beans, and who do not mind the open-session-in-view pattern, Tapestry has JPA Integration and Hibernate Integration.

References: "Why EJB3?" in JumpStart FAQ, What is an Enterprise Bean?.

Home


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<!-- We need a doctype to allow us to use special characters like &nbsp; 
     We use a "strict" DTD to make IE follow the alignment rules. -->
     
<html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_4.xsd">
<body class="container">

    <h3>Session Beans</h3>
    
    In JumpStart, the business logic is in Java EE Session Beans, such as PersonFinderService and PersonManagerService.<br/><br/>

    Here we've used PersonFinderService to find entity Person with id = 1. 
    The <code>@EJB</code> annotation is explained in the next example.

    <div class="eg">
        <t:beandisplay object="person"/>
    </div>

    For those of you who do not want to use Session Beans, and who do not mind the open-session-in-view pattern, Tapestry has 
    <a href="http://tapestry.apache.org/integrating-with-jpa.html">JPA Integration</a> and 
    <a href="http://tapestry.apache.org/hibernate.html">Hibernate Integration</a>.<br/><br/>

    References: <a href="http://jumpstart.doublenegative.com.au/faq.html">"Why EJB3?" in JumpStart FAQ</a>, 
    <a href="http://docs.oracle.com/javaee/7/tutorial/doc/ejb-intro001.htm#GIPMB">What is an Enterprise Bean?</a>.<br/><br/>
    
    <t:pagelink page="Index">Home</t:pagelink><br/><br/>

    <t:tabgroup>
        <t:sourcecodetab src="/web/src/main/java/jumpstart/web/pages/examples/state/SessionBeans.tml"/>
        <t:sourcecodetab src="/web/src/main/java/jumpstart/web/pages/examples/state/SessionBeans.java"/>
        <t:sourcecodetab src="/web/src/main/resources/META-INF/assets/css/examples/plain.css"/>
        <t:sourcecodetab src="/business/src/main/java/jumpstart/business/domain/person/iface/IPersonFinderServiceLocal.java"/>
        <t:sourcecodetab src="/business/src/main/java/jumpstart/business/domain/person/iface/IPersonFinderServiceRemote.java"/>
        <t:sourcecodetab src="/business/src/main/java/jumpstart/business/domain/person/PersonFinderService.java"/>
        <t:sourcecodetab src="/business/src/main/java/jumpstart/business/domain/person/iface/IPersonManagerServiceLocal.java"/>
        <t:sourcecodetab src="/business/src/main/java/jumpstart/business/domain/person/iface/IPersonManagerServiceRemote.java"/>
        <t:sourcecodetab src="/business/src/main/java/jumpstart/business/domain/person/PersonManagerService.java"/>
        <t:sourcecodetab src="/business/src/main/java/jumpstart/business/domain/person/Person.java"/>
        <t:sourcecodetab src="/business/src/main/java/jumpstart/business/domain/person/Regions.java"/>
        <t:sourcecodetab src="/business/src/main/java/jumpstart/business/domain/person/ValidationException.java"/>
    </t:tabgroup>
</body>
</html>


package jumpstart.web.pages.examples.state;

import javax.ejb.EJB;

import jumpstart.business.domain.person.Person;
import jumpstart.business.domain.person.iface.IPersonFinderServiceLocal;

import org.apache.tapestry5.annotations.Import;
import org.apache.tapestry5.annotations.Property;

@Import(stylesheet = "css/examples/plain.css")
public class SessionBeans {

    // Screen fields

    @Property
    private Person person;

    // Generally useful bits and pieces

    @EJB
    private IPersonFinderServiceLocal personFinderService;

    // The code

    void setupRender() throws Exception {
        person = personFinderService.findPerson(1L);

        if (person == null) {
            throw new IllegalStateException("Database data has not been set up!");
        }
    }

}


.eg {
                margin: 20px 0;
                padding: 14px;
                border: 1px solid #ddd;
                border-radius: 6px;
                -webkit-border-radius: 6px;
                -mox-border-radius: 6px;
}


package jumpstart.business.domain.person.iface;

/**
 * The <code>IPersonServiceLocal</code> bean exposes the business methods in the interface.
 */
public interface IPersonFinderServiceLocal extends IPersonFinderServiceRemote {
}


package jumpstart.business.domain.person.iface;

import java.util.List;

import jumpstart.business.domain.person.Person;
import jumpstart.business.domain.person.Regions;
import jumpstart.util.query.SortCriterion;

/**
 * The <code>IPersonFinderServiceRemote</code> bean exposes the business methods in the interface.
 */
public interface IPersonFinderServiceRemote {

    // Person

    Person findPerson(Long id);

    long countPersons();
    
    List<Person> findPersons(int maxResults);

    List<Person> findPersons(String partialName, int maxResults);

    List<Person> findPersonsByFirstName(String firstName);

    List<Person> findPersonsByLastName(String lastName);

    long countPersons(String partialName);
    
    List<Person> findPersons(String partialName, int startIndex, int maxResults);

    List<Person> findPersons(int startIndex, int maxResults, List<SortCriterion> sortCriteria);

    long countPersons(String firstNameStartsWith, String lastNameStartsWith, Regions region);
    
    List<Person> findPersons(String firstNameStartsWith, String lastNameStartsWith, Regions region, int startIndex,
            int maxResults, List<SortCriterion> sortCriteria);
    
}


package jumpstart.business.domain.person;

import java.util.Arrays;
import java.util.List;

import javax.ejb.Local;
import javax.ejb.Remote;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

import jumpstart.business.domain.person.iface.IPersonFinderServiceLocal;
import jumpstart.business.domain.person.iface.IPersonFinderServiceRemote;
import jumpstart.util.query.SortCriterion;

@Stateless
@Local(IPersonFinderServiceLocal.class)
@Remote(IPersonFinderServiceRemote.class)
public class PersonFinderService implements IPersonFinderServiceLocal, IPersonFinderServiceRemote {

    @PersistenceContext(unitName = "jumpstart")
    private EntityManager em;

    public Person findPerson(Long id) {
        return em.find(Person.class, id);
    }

    public long countPersons() {
        return (Long) em.createQuery("select count(p) from Person p").getSingleResult();
    }

    @SuppressWarnings("unchecked")
    public List<Person> findPersons(int maxResults) {
        return em.createQuery("select p from Person p order by lower(p.firstName), lower(p.lastName)")
                .setMaxResults(maxResults).getResultList();
    }

    @SuppressWarnings("unchecked")
    public List<Person> findPersons(String partialName, int maxResults) {
        String searchName = partialName == null ? "" : partialName.toLowerCase();

        StringBuilder buf = new StringBuilder();
        buf.append("select p from Person p");
        buf.append(" where lower(firstName) like :firstName");
        buf.append(" or lower(lastName) like :lastName");
        buf.append(" order by lower(p.firstName), lower(p.lastName)");

        Query q = em.createQuery(buf.toString());
        q.setParameter("firstName", "%" + searchName + "%");
        q.setParameter("lastName", "%" + searchName + "%");

        List<Person> l = q.setMaxResults(maxResults).getResultList();
        return l;
    }

    @SuppressWarnings("unchecked")
    public List<Person> findPersonsByFirstName(String firstName) {
        String searchName = firstName == null ? "" : firstName.trim().toLowerCase();

        StringBuilder buf = new StringBuilder();
        buf.append("select p from Person p");
        buf.append(" where lower(p.firstName) = :searchName");
        buf.append(" order by lower(p.firstName), lower(p.lastName)");

        Query q = em.createQuery(buf.toString());
        q.setParameter("searchName", searchName);

        List<Person> l = q.getResultList();
        return l;
    }

    @SuppressWarnings("unchecked")
    public List<Person> findPersonsByLastName(String lastName) {
        String searchName = lastName == null ? "" : lastName.trim().toLowerCase();

        StringBuilder buf = new StringBuilder();
        buf.append("select p from Person p");
        buf.append(" where lower(p.lastName) = :searchName");
        buf.append(" order by lower(p.lastName), lower(p.firstName)");

        Query q = em.createQuery(buf.toString());
        q.setParameter("searchName", searchName);

        List<Person> l = q.getResultList();
        return l;
    }

    public long countPersons(String partialName) {
        return (Long) findPersons(true, partialName, 0, 0);
    }

    @SuppressWarnings("unchecked")
    public List<Person> findPersons(String partialName, int startIndex, int maxResults) {
        return (List<Person>) findPersons(false, partialName, startIndex, maxResults);
    }

    @SuppressWarnings("unchecked")
    private Object findPersons(boolean counting, String partialName, int startIndex, int maxResults) {
        String searchName = partialName == null ? "" : partialName.toLowerCase();

        StringBuilder buf = new StringBuilder();

        if (counting) {
            buf.append("select count(p) from Person p");
        }
        else {
            buf.append("select p from Person p");
        }
        buf.append(" where lower(firstName) like :firstName");
        buf.append(" or lower(lastName) like :lastName");

        if (!counting) {
            buf.append(" order by lower(p.firstName), lower(p.lastName)");
        }

        Query q = em.createQuery(buf.toString());
        q.setParameter("firstName", "%" + searchName + "%");
        q.setParameter("lastName", "%" + searchName + "%");

        if (counting) {
            Long qty = (Long) q.getSingleResult();
            return qty;
        }
        else {
            List<Person> l = q.setFirstResult(startIndex).setMaxResults(maxResults).getResultList();
            return l;
        }
    }

    @SuppressWarnings("unchecked")
    public List<Person> findPersons(int startIndex, int maxResults, List<SortCriterion> sortCriteria) {
        final List<String> PROPERTIES_TO_LOWER_FOR_SORT = Arrays.asList("firstName", "lastName");

        // Here we use JPQL. An alternative is to use javax.persistence.criteria.CriteriaQuery. For an example see
        // Tapestry's JpaGridDataSource.

        StringBuilder buf = new StringBuilder();
        buf.append("select p from Person p");
        buf.append(" order by ");

        boolean firstOrderByItem = true;
        boolean orderByIncludesId = false;

        for (SortCriterion sortCriterion : sortCriteria) {
            String propertyName = sortCriterion.getPropertyName();

            // Append an "order by" item, eg. "startDate", or ", lower(firstName) desc".

            if (!firstOrderByItem) {
                buf.append(", ");
            }
            if (PROPERTIES_TO_LOWER_FOR_SORT.contains(propertyName)) {
                buf.append("lower(").append(propertyName).append(")");
            }
            else {
                buf.append(propertyName);
            }
            buf.append(sortCriterion.getSortDirection().toStringForJpql());

            // We need to know later whether the "order by" includes id.

            if (propertyName.equals("id")) {
                orderByIncludesId = true;
            }
            firstOrderByItem = false;
        }

        // Ensure sequence is predictable by ensuring a unique property, id, is in the "order by".

        if (!orderByIncludesId) {
            if (!firstOrderByItem) {
                buf.append(", ");
            }
            buf.append("id");
        }

        Query q = em.createQuery(buf.toString());

        List<Person> l = q.setFirstResult(startIndex).setMaxResults(maxResults).getResultList();
        return l;
    }

    public long countPersons(String firstNameStartsWith, String lastNameStartsWith, Regions region) {
        return (Long) findPersons(true, firstNameStartsWith, lastNameStartsWith, region, 0, 0, null);
    }

    @SuppressWarnings("unchecked")
    public List<Person> findPersons(String firstNameStartsWith, String lastNameStartsWith, Regions region,
            int startIndex, int maxResults, List<SortCriterion> sortCriteria) {
        return (List<Person>) findPersons(false, firstNameStartsWith, lastNameStartsWith, region, startIndex,
                maxResults, sortCriteria);
    }

    /**
     * Finds persons who match the criteria.
     * If counting == true, returns the count of persons found, as a Long.
     * Else, returns the persons found, as a List<Person>.
     */
    @SuppressWarnings("unchecked")
    private Object findPersons(boolean counting, String firstNameStartsWith, String lastNameStartsWith, Regions region,
            int startIndex, int maxResults, List<SortCriterion> sortCriteria) {
        final List<String> PROPERTIES_TO_LOWER_FOR_SORT = Arrays.asList("firstName", "lastName");

        String searchFirstName = firstNameStartsWith == null ? "" : firstNameStartsWith.toLowerCase();
        String searchLastName = lastNameStartsWith == null ? "" : lastNameStartsWith.toLowerCase();

        StringBuilder buf = new StringBuilder();

        if (counting) {
            buf.append("select count(p) from Person p");
        }
        else {
            buf.append("select p from Person p");
        }

        buf.append(" where lower(firstName) like :firstName");
        buf.append(" and lower(lastName) like :lastName");
        if (region != null) {
            buf.append(" and region = :region");
        }

        if (!counting) {
            buf.append(" order by ");

            boolean firstOrderByItem = true;
            boolean orderByIncludesId = false;

            for (SortCriterion sortCriterion : sortCriteria) {
                String propertyName = sortCriterion.getPropertyName();

                // Append an "order by" item, eg. "startDate", or ", lower(firstName) desc".

                if (!firstOrderByItem) {
                    buf.append(", ");
                }
                if (PROPERTIES_TO_LOWER_FOR_SORT.contains(propertyName)) {
                    buf.append("lower(").append(propertyName).append(")");
                }
                else {
                    buf.append(propertyName);
                }
                buf.append(sortCriterion.getSortDirection().toStringForJpql());

                // We need to know later whether the "order by" includes id.

                if (propertyName.equals("id")) {
                    orderByIncludesId = true;
                }
                firstOrderByItem = false;
            }

            // Ensure sequence is predictable by ensuring a unique property, id, is in the "order by".

            if (!orderByIncludesId) {
                if (!firstOrderByItem) {
                    buf.append(", ");
                }
                buf.append("id");
            }
        }

        Query q = em.createQuery(buf.toString());
        q.setParameter("firstName", searchFirstName + "%");
        q.setParameter("lastName", searchLastName + "%");
        if (region != null) {
            q.setParameter("region", region);
        }

        if (counting) {
            Long qty = (Long) q.getSingleResult();
            return qty;
        }
        else {
            List<Person> l = q.setFirstResult(startIndex).setMaxResults(maxResults).getResultList();
            return l;
        }
    }

}


package jumpstart.business.domain.person.iface;

/**
 * The <code>IPersonManagerServiceLocal</code> bean exposes the business methods in the interface.
 */
public interface IPersonManagerServiceLocal extends IPersonManagerServiceRemote {
}


package jumpstart.business.domain.person.iface;

import java.util.List;

import jumpstart.business.commons.IdVersion;
import jumpstart.business.domain.person.Person;

/**
 * The <code>IPersonManagerServiceRemote</code> bean exposes the business methods in the interface.
 */
public interface IPersonManagerServiceRemote {

    // Person

    Person createPerson(Person person);

    void createPersons(List<Person> persons);

    Person changePerson(Person person);

    void changePersons(List<Person> persons);

    void changePersonsByDTOs(List<PersonDTO> persons);

    void bulkEditPersons(List<Person> personsToCreate, List<Person> personsToChange, List<IdVersion> personsToDelete);

    void bulkEditPersonsByDTOs(List<PersonDTO> personsToCreate, List<PersonDTO> personsToChange,
            List<IdVersion> personsToDelete);

    void deletePerson(Long id, Integer version);

}


package jumpstart.business.domain.person;

import java.util.List;

import javax.ejb.Local;
import javax.ejb.Remote;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.EntityNotFoundException;
import javax.persistence.OptimisticLockException;
import javax.persistence.PersistenceContext;

import jumpstart.business.commons.IdVersion;
import jumpstart.business.domain.person.iface.IPersonManagerServiceLocal;
import jumpstart.business.domain.person.iface.IPersonManagerServiceRemote;
import jumpstart.business.domain.person.iface.PersonDTO;

@Stateless
@Local(IPersonManagerServiceLocal.class)
@Remote(IPersonManagerServiceRemote.class)
public class PersonManagerService implements IPersonManagerServiceLocal, IPersonManagerServiceRemote {

    @PersistenceContext(unitName = "jumpstart")
    public EntityManager em;

    public Person createPerson(Person person) {
        em.persist(person);
        return person;
    }

    public void createPersons(List<Person> persons) {
        for (Person person : persons) {
            em.persist(person);
        }
    }

    public Person changePerson(Person person) {
        Person p = em.merge(person);
        // Flush to work around OPENEJB issue https://issues.apache.org/jira/browse/OPENEJB-782
        em.flush();

        // If id is different it means the person did not exist so merge has created a new one.
        if (!p.getId().equals(person.getId())) {
            throw new EntityNotFoundException("Person no longer exists.");
        }
        
        return p;
    }

    public void changePersons(List<Person> persons) {
        for (Person person : persons) {
            Person p = em.merge(person);

            // If id is different it means the person did not exist so merge has created a new one.
            if (!p.getId().equals(person.getId())) {
                throw new EntityNotFoundException("Person no longer exists.");
            }
        }
    }

    public void changePersonsByDTOs(List<PersonDTO> persons) {
        for (PersonDTO person : persons) {
            Person p = em.find(Person.class, person.getId());

            if (p == null) {
                throw new EntityNotFoundException("Person no longer exists.");
            }

            if (!p.getVersion().equals(person.getVersion())) {
                throw new OptimisticLockException();
            }

            p.setFirstName(person.getFirstName());
        }
    }

    public void bulkEditPersons(List<Person> personsToCreate, List<Person> personsToChange,
            List<IdVersion> personsToDelete) {
        for (Person person : personsToCreate) {
            em.persist(person);
        }
        for (Person person : personsToChange) {
            Person p = em.merge(person);

            // If id is different it means the person did not exist so merge has created a new one.
            if (!p.getId().equals(person.getId())) {
                throw new EntityNotFoundException("Person no longer exists.");
            }
        }
        for (IdVersion idVersion : personsToDelete) {
            Person p = em.find(Person.class, idVersion.getId());

            if (p == null) {
                throw new EntityNotFoundException("Person no longer exists.");
            }

            if (!p.getVersion().equals(idVersion.getVersion())) {
                throw new OptimisticLockException();
            }

            em.remove(p);
        }
    }

    public void bulkEditPersonsByDTOs(List<PersonDTO> personsToCreate, List<PersonDTO> personsToChange,
            List<IdVersion> personsToDelete) {
        for (PersonDTO p : personsToCreate) {
            Person person = new Person(p.getFirstName(), p.getLastName(), p.getRegion(), p.getStartDate());
            em.persist(person);
        }
        for (PersonDTO person : personsToChange) {
            Person p = em.find(Person.class, person.getId());

            if (p == null) {
                throw new EntityNotFoundException("Person no longer exists.");
            }

            if (!p.getVersion().equals(person.getVersion())) {
                throw new OptimisticLockException();
            }

            p.setFirstName(person.getFirstName());
            p.setLastName(person.getLastName());
            p.setRegion(person.getRegion());
            p.setStartDate(person.getStartDate());
        }
        for (IdVersion idVersion : personsToDelete) {
            Person p = em.find(Person.class, idVersion.getId());

            if (p == null) {
                throw new EntityNotFoundException("Person no longer exists.");
            }

            if (!p.getVersion().equals(idVersion.getVersion())) {
                throw new OptimisticLockException();
            }

            em.remove(p);
        }
    }

    public void deletePerson(Long id, Integer version) {
        Person p = em.find(Person.class, id);

        if (p == null) {
            throw new EntityNotFoundException("Person no longer exists.");
        }

        if (!p.getVersion().equals(version)) {
            throw new OptimisticLockException();
        }

        em.remove(p);
        // Flush to work around OPENEJB issue https://issues.apache.org/jira/browse/OPENEJB-782
        em.flush();
    }

}


package jumpstart.business.domain.person;

import java.io.Serializable;
import java.util.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.EnumType;
import javax.persistence.Enumerated;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.PrePersist;
import javax.persistence.PreUpdate;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.Version;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;


/**
 * The Person entity.
 */
@Entity
@SuppressWarnings("serial")
public class Person implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(nullable = false)
    private Long id;

    @Version
    @Column(nullable = false)
    private Integer version;

    @Column(length = 10, nullable = false)
    @NotNull
    @Size(max = 10)
    private String firstName;

    @Column(length = 10, nullable = false)
    @NotNull
    @Size(max = 10)
    private String lastName;
    
    @Enumerated(EnumType.STRING)
    @NotNull
    private Regions region;

    @Temporal(TemporalType.DATE)
    @NotNull
    private Date startDate;

    public String toString() {
        final String DIVIDER = ", ";
        
        StringBuilder buf = new StringBuilder();
        buf.append(this.getClass().getSimpleName() + ": ");
        buf.append("[");
        buf.append("id=" + id + DIVIDER);
        buf.append("version=" + version + DIVIDER);
        buf.append("firstName=" + firstName + DIVIDER);
        buf.append("lastName=" + lastName + DIVIDER);
        buf.append("region=" + region + DIVIDER);
        buf.append("startDate=" + startDate);
        buf.append("]");
        return buf.toString();
    }

    // Default constructor is required by JPA.
    public Person() {
    }

    public Person(String firstName, String lastName, Regions region, Date startDate) {
        super();
        this.firstName = firstName;
        this.lastName = lastName;
        this.region = region;
        this.startDate = startDate;
    }

    // The need for an equals() method is discussed at http://www.hibernate.org/109.html
    
    @Override
    public boolean equals(Object obj) {
        return (obj == this) || (obj instanceof Person) && id != null && id.equals(((Person) obj).getId());
    }

    // The need for a hashCode() method is discussed at http://www.hibernate.org/109.html

    @Override
    public int hashCode() {
        return id == null ? super.hashCode() : id.hashCode();
    }

    @PrePersist
    @PreUpdate
    public void validate() throws ValidationException {

    }

    public Long getId() {
        return id;
    }

    public Integer getVersion() {
        return version;
    }

    public void setVersion(Integer version) {
        this.version = version;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public Regions getRegion() {
        return region;
    }

    public void setRegion(Regions region) {
        this.region = region;
    }

    public Date getStartDate() {
        return startDate;
    }

    public void setStartDate(Date startDate) {
        this.startDate = startDate;
    }

}


package jumpstart.business.domain.person;

public enum Regions {
    EAST_COAST, WEST_COAST;
}


package jumpstart.business.domain.person;

import javax.ejb.ApplicationException;

@ApplicationException(rollback = true)
@SuppressWarnings("serial")
public class ValidationException extends Exception {

    public ValidationException(String message) {
        super(message);
    }

}