Example of JPA entities that use JavaFX properties. These use a "super-lazy" idiom for instantiating the properties, and implement Externalizable to work around the lack of Serialization support in the FX property classes.

Investigator.java

package edu.marshall.genomics.lims.entities;

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;

import javax.persistence.Access;
import javax.persistence.AccessType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

/**
 * Entity implementation class for Entity: Investigator
 *
 */
@Entity
@Access(AccessType.PROPERTY)
@Table(name="investigators")
@NamedQuery(name="Investigator.findAll", query="SELECT i from Investigator i")
public class Investigator implements Externalizable {

	
	private static final long serialVersionUID = 1L;

	private IntegerProperty id ;
	private int _id ;
	@Id
	@Column(name="inv_id")
	@GeneratedValue(strategy=GenerationType.AUTO)
	public int getId() {
		if (id==null) {
			return _id ;
		} else {
			return id.get();
		}
	}
	
	public void setId(int id) {
		if (this.id==null) {
			_id=id ;
		} else {
			this.id.set(id);
		}
	}
	
	public IntegerProperty idProperty() {
		if (id==null) {
			id = new SimpleIntegerProperty(this, "id", _id);
		}
		return id ;
	}
	
	private StringProperty email ;
	private String _email ;
	@Column(name="email")
	public String getEmail() {
		if (email == null) {
			return _email ;
		} else {
			return email.get() ;
		}
	}
	
	public void setEmail(String email) {
		if (this.email == null) {
			_email = email ;
		} else {
			this.email.set(email);
		}
	}
	
	public StringProperty emailProperty() {
		if (email == null) {
			email = new SimpleStringProperty(this, "email", _email);
		}
		return email ;
	}
	
	private StringProperty firstName ;
	private String _firstName ;
	@Column(name="firstName")
	public String getFirstName() {
		if (firstName == null) {
			return _firstName ;
		} else {
			return firstName.get();
		}
	}
	public void setFirstName(String firstName) {
		if (this.firstName == null) {
			_firstName = firstName ;
		} else {
			this.firstName.set(firstName);
		}
	}
	
	public StringProperty firstNameProperty() {
		if (firstName == null) {
			firstName = new SimpleStringProperty(this, "firstName", _firstName);
		}
		return firstName ;
	}
	
	private StringProperty lastName ;
	private String _lastName ;
	@Column(name="lastName")
	public String getLastName() {
		if (lastName == null) {
			return _lastName ;
		} else {
			return lastName.get();
		}
	}
	public void setLastName(String lastName) {
		if (this.lastName == null) {
			_lastName = lastName ;
		} else {
			this.lastName.set(lastName);
		}
	}
	public StringProperty lastNameProperty() {
		if (lastName == null) {
			this.lastName = new SimpleStringProperty(this, "lastName", _lastName);
		}
		return lastName ;
	}
	
	private StringProperty institution ;
	private String _institution ;
	@Column(name="institution")
	public String getInstitution() {
		if (institution == null) {
			return _institution ;
		} else {
			return institution.get();
		}
	}
	public void setInstitution(String institution) {
		if (this.institution == null) {
			_institution = institution ;
		} else {
			this.institution.set(institution);
		}
	}
	
	public StringProperty institutionProperty() {
		if (institution == null) {
			institution = new SimpleStringProperty(this, "institution", _institution);
		}
		return institution ;
	}

	@Override
	public void writeExternal(ObjectOutput out) throws IOException {
		out.writeInt(getId());
		out.writeObject(getFirstName());
		out.writeObject(getLastName());
		out.writeObject(getEmail());
		out.writeObject(getInstitution());
	}

	@Override
	public void readExternal(ObjectInput in) throws IOException,
			ClassNotFoundException {
		setId(in.readInt());
		setFirstName((String) in.readObject());
		setLastName((String) in.readObject());
		setEmail((String) in.readObject());
		setInstitution((String) in.readObject());
	}
   
}

Project.java

package edu.marshall.genomics.lims.entities;

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import javafx.beans.property.IntegerProperty;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;

import javax.persistence.Access;
import javax.persistence.AccessType;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

/**
 * Entity implementation class for Entity: Project
 *
 */
@Entity
@Access(AccessType.PROPERTY)
@Table(name="projects")

@NamedQueries(
		{
			@NamedQuery(name="Project.findAll", query="SELECT p from Project p"),
			@NamedQuery(name="Project.byInvestigator", query="SELECT p FROM Project p WHERE p.investigator=:investigator"),
		}
)

public class Project implements Externalizable {

	private static final long serialVersionUID = 1L;

	private IntegerProperty id;
	private int _id;

	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	@Column(name = "project_id")
	public final int getId() {
		if (id == null) {
			return _id;
		} else {
			return id.get();
		}
	}

	public final void setId(int id) {
		if (this.id == null) {
			_id = id;
		} else {
			this.id.set(id);
		}
	}
	
	public IntegerProperty idProperty() {
		if (id == null) {
			id = new SimpleIntegerProperty(this, "id", _id);
		} 
		return id ;
	}
	
	private StringProperty title ;
	private String _title ;
	@Column(name="title")
	public final String getTitle() {
		if (this.title == null) {
			return _title ;
		} else {
			return title.get();
		}
	}
	public final void setTitle(String title) {
		if (this.title == null) {
			_title = title ;
		} else {
			this.title.set(title);
		}
	}
	public StringProperty titleProperty() {
		if (title == null) {
			title = new SimpleStringProperty(this, "title", _title);
		}
		return title ;
	}
	
	private ObjectProperty<Investigator> investigator ;
	private Investigator _investigator ;
	@ManyToOne(cascade=CascadeType.MERGE, fetch=FetchType.EAGER)
	@JoinColumn(name="investigator", referencedColumnName="inv_id")
	public final Investigator getInvestigator() {
		if (investigator == null) {
			return _investigator ;
		} else {
			return investigator.get();
		}
	}
	public final void setInvestigator(Investigator investigator) {
		if (this.investigator == null) {
			_investigator = investigator ;
		} else {
			this.investigator.set(investigator);
		}
	}
	public ObjectProperty<Investigator> investigatorProperty() {
		if (investigator == null) {
			investigator = new SimpleObjectProperty<>(this, "investigator", _investigator);
		}
		return investigator ;
	}

	@Override
	public void writeExternal(ObjectOutput out) throws IOException {
		out.writeInt(getId());
		out.writeObject(getTitle());
		out.writeObject(getInvestigator());
	}

	@Override
	public void readExternal(ObjectInput in) throws IOException,
			ClassNotFoundException {
		setId(in.readInt());
		setTitle((String)in.readObject());
		setInvestigator((Investigator) in.readObject());
	}

}

Sample.java

package edu.marshall.genomics.lims.entities;

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import javafx.beans.property.IntegerProperty;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;

import javax.persistence.Access;
import javax.persistence.AccessType;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

/**
 * Entity implementation class for Entity: samples
 *
 */
@Entity
@Access(AccessType.PROPERTY)
@Table(name = "samples")
@NamedQueries({
		@NamedQuery(name = "Sample.findAll", query = "SELECT s FROM Sample s"),
		@NamedQuery(name = "Sample.byProject", query = "SELECT s FROM Sample s where s.project=:project") })
public class Sample implements Externalizable {

	private static final long serialVersionUID = 1L;

	private IntegerProperty id;
	private int _id;

	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	public final int getId() {
		if (this.id == null) {
			return _id;
		} else {
			return id.get();
		}
	}

	public final void setId(int id) {
		if (this.id == null) {
			_id = id;
		} else {
			this.id.set(id);
		}
	}

	public IntegerProperty idProperty() {
		if (id == null) {
			id = new SimpleIntegerProperty(this, "id", _id);
		}
		return id;
	}

	private StringProperty sampleId;
	private String _sampleId;

	@Column(name = "sampleId")
	public final String getSampleId() {
		if (sampleId == null) {
			return _sampleId;
		} else {
			return sampleId.get();
		}
	}

	public final void setSampleId(String sampleId) {
		if (this.sampleId == null) {
			_sampleId = sampleId;
		} else {
			this.sampleId.set(sampleId);
		}
	}

	public StringProperty sampleIdProperty() {
		if (sampleId == null) {
			sampleId = new SimpleStringProperty(this, "sampleId", _sampleId);
		}
		return sampleId;
	}

	private ObjectProperty<Project> project;
	private Project _project;

	@JoinColumn(name = "project", referencedColumnName = "project_id")
	@ManyToOne(cascade = CascadeType.MERGE, fetch = FetchType.EAGER)
	public final Project getProject() {
		if (project == null) {
			return _project;
		} else {
			return project.get();
		}
	}

	public final void setProject(Project project) {
		if (this.project == null) {
			_project = project;
		} else {
			this.project.set(project);
		}
	}

	public ObjectProperty<Project> projectProperty() {
		if (project == null) {
			project = new SimpleObjectProperty<>(this, "project", _project);
		}
		return project;
	}

	@Override
	public void writeExternal(ObjectOutput out) throws IOException {
		out.writeInt(getId());
		out.writeObject(getSampleId());
		out.writeObject(getProject());
	}

	@Override
	public void readExternal(ObjectInput in) throws IOException,
			ClassNotFoundException {
		setId(in.readInt());
		setSampleId((String) in.readObject());
		setProject((Project) in.readObject());
	}

}