JPA TransactionRequiredException

[Fintan Conway]

Hello,

I have a simple JSF 2.3 application and I am trying to use JPA to persist my data to the database.

I am using TomEE 8.0.6.

I am not using Spring.  I am not using EJB.

Unfortunately, I am getting a "Transaction required" exception when I try to persist data to the database

Feb 25, 2021 1:33:38 PM org.apache.catalina.core.StandardWrapperValve invoke SEVERE: Servlet.service() for servlet [Faces Servlet] in context with path [/JSF_add_persistence] threw exception [javax.el.ELException: javax.persistence.TransactionRequiredException] with root cause javax.persistence.TransactionRequiredException at org.apache.openejb.persistence.JtaEntityManager.assertTransactionActive(JtaEntityManager.java:160) at org.apache.openejb.persistence.JtaEntityManager.persist(JtaEntityManager.java:190) at com.waycontech.jsf.add.persistence.StudentController.addStudent(StudentController.java:42) at com.waycontech.jsf.add.persistence.StudentController$$OwbNormalScopeProxy0.addStudent(com/waycontech/jsf/add/persistence/StudentController.java) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) etc.....

My configuration files
/src/META-INF/persistence.xml
<?xml version="1.0" encoding="UTF-8"?> <persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"> <persistence-unit name="JSF add persistence"> <jta-data-source>studentDatabase</jta-data-source> <non-jta-data-source>studentDatabaseUnmanaged</non-jta-data-source> <class>com.waycontech.jsf.add.persistence.Student</class> <properties> <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)"/> </properties> </persistence-unit> </persistence>

/WebContent/WEB-INF/resources.xml
<?xml version='1.0' encoding='UTF-8'?> <resources> <Resource id="studentDatabase" type="DataSource"> JdbcDriver org.mariadb.jdbc.Driver JdbcUrl jdbc:mariadb://localhost:3306/student_tracker UserName demo Password demo JtaManaged true    </Resource> </resources>

My Java files

package com.waycontech.jsf.add.persistence;

import javax.enterprise.context.RequestScoped;
import javax.inject.Named;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Named @RequestScoped
@Entity @Table(name="student")
public class Student {
	@Id @GeneratedValue(strategy=GenerationType.AUTO)
	@Column(name="id")
	private long id;
	
	@Column(name="first_name", length=45)
	private String firstName;
	@Column(name="last_name", length=45)
	private String lastName;
	@Column(name="email", length=45)
	private String email;
	
	public long getId() {
		return id;
	}
	public void setId(long id) {
		this.id = id;
	}
	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 String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	
	@Override
	public String toString() {
		return "{  " + firstName + " " + lastName + ";  Email:  " + email + "  }";
	}
	
}

package com.waycontech.jsf.add.persistence;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import javax.annotation.PostConstruct;
import javax.enterprise.context.RequestScoped;
import javax.enterprise.context.SessionScoped;
import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.inject.Named;
import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import javax.persistence.criteria.CriteriaQuery;

//@SessionScoped
@RequestScoped
@Named
public class StudentController implements Serializable {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	@PersistenceContext(unitName="JSF add persistence")
	private EntityManager entityManager;
	
	private List<Student> students;
	
	public StudentController() throws Exception {
		students = new ArrayList<>();
	}
	
	//@TransactionAttribute(TransactionAttributeType.REQUIRED)
	public void addStudent(Student student) {
		System.out.println("Adding Student ::" + student);
//		entityManager.getTransaction().begin();
		entityManager.persist(student);
//		entityManager.getTransaction().commit();
	}
	
	public List<Student> getStudents() {
		return students;
	}

	public void setStudents(List<Student> students) {
		this.students = students;
	}
	
	public void loadStudents() {
		// Retrieve the list of students from the DB
		// Fill the 'students' Array list
//		entityManager.getTransaction().begin();
		CriteriaQuery<Student> cq = entityManager.getCriteriaBuilder().createQuery(Student.class);
		cq.select(cq.from(Student.class));
		students = entityManager.createQuery(cq).getResultList();
//		entityManager.getTransaction().commit();
	}
	
	private void addErrorMessage(Exception ex) {
		FacesMessage message = new FacesMessage("Error :  " + ex.getMessage());
		FacesContext.getCurrentInstance().addMessage(null, message);
	}
	
}

My JSF page
/WebContent/addStudentForm.xhtml

<!DOCTYPE html>
<html lang="en"
      xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://xmlns.jcp.org/jsf/html"
      xmlns:ui="http://xmlns.jcp.org/jsf/facelets"
      xmlns:f="http://xmlns.jcp.org/jsf/core"
      xmlns:pt="http://xmlns.jcp.org/jsf/passthrough">
      
<h:head>
	<meta name="viewport" content="width=device-width, initial-scale=1.0" />
	<meta http-equiv="Content-Type" content="text-html; charset=UTF-8" />
	
	<title>Add Student</title>
	<h:outputStylesheet library="css" name="listStudents.css"/>
</h:head>
<h:body>
<ui:debug hotkey="q" render="true"/>
	<div id="wrapper">
		<div id="header">
			<h2>Foobar University</h2>
		</div>
	</div>
	
	<div id="container">
		<h3>Add Student</h3>
		<h:messages globalOnly="true" />
		<h:form id="addStudentForm">
			<h:panelGrid columns="3">
				<h:outputLabel for="addStudentFirst">First Name :</h:outputLabel>
				<h:inputText value="#{student.firstName}" id="addStudentFirst" pt:placeholder="First name"/>
				<h:message for="addStudentFirst" />
				
				<h:outputLabel for="addStudentLast">Last Name :</h:outputLabel>
				<h:inputText value="#{student.lastName}" id="addStudentLast" pt:placeholder="Last name"/>
				<h:message for="addStudentLast" />
				
				<h:outputLabel for="addStudentEmail">Email :</h:outputLabel>
				<h:inputText value="#{student.email}" required="true" id="addStudentEmail"
						pt:placeholder="Email Address"
						requiredMessage="Your email is mandatory." />
				<h:message for="addStudentEmail" />
				
				<h:commandButton value="Add Student" action="#{studentController.addStudent(student)}" />		
			</h:panelGrid>
		</h:form>
		<p><h:outputLink value="addStudentList.xhtml">Back to list</h:outputLink></p>
	</div>
</h:body>
</html>

When I call studentController.addStudent(student) the error gets thrown on the line entityManager.persist(student);

I know the DB connection is working because the following page calls studentController.loadStudents() and displays a list of the students.

/WebContent/addStudentList.xhtml

<!DOCTYPE html>
<html lang="en"
      xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://xmlns.jcp.org/jsf/html"
      xmlns:ui="http://xmlns.jcp.org/jsf/facelets"
      xmlns:f="http://xmlns.jcp.org/jsf/core"
      xmlns:a="http://xmlns.jcp.org/jsf/passthrough">
      

	<f:event listener="#{studentController.loadStudents()}" type="preRenderView" />
      
<h:head>
	<meta name="viewport" content="width=device-width, initial-scale=1.0" />
	<meta http-equiv="Content-Type" content="text-html; charset=UTF-8" />
	
	<title>Student Tracker App</title>
	<h:outputStylesheet library="css" name="listStudents.css"/>
</h:head>
<h:body>
	<div id="wrapper">
		<div id="header">
			<h2>Foobar University</h2>
		</div>
	</div>
	
	<div id="container">
		<div id="content">
			<h:messages globalOnly="true" />
			
			<h:button value="Add Student" styleClass="addStudentButton" 
					outcome="addStudentForm" />
			<h:form>
				<h:dataTable value="#{studentController.students}"
					var="varStudent" border="1"
					styleClass="demoTable" headerClass="demoTableHeader"
					rowClasses="demoTableOddRow, demoTableEvenRow">
					<h:column>
						<f:facet name="header">First Name</f:facet>
						#{varStudent.firstName}
					</h:column>
					<h:column>
						<f:facet name="header">Last Name</f:facet>
						#{varStudent.lastName}
					</h:column>
					<h:column>
						<f:facet name="header">Email</f:facet>
						#{varStudent.email}
					</h:column>
				</h:dataTable>
			</h:form>
		</div>
	</div>
	<h:messages />
</h:body>
</html>

Any ideas on how to get the transactions working?

Many thanks

[Tim Holloway]

I'm not sure why you're using TomEE if you're not using EJB, If all you want is JPA, ordinary Tomcat can do that without the overhead. And remember, JPA is a subset of EJB3!

A note on your "action". That's not how JSF wants actions to work. An action method is supposed to be a method that takes no parameters and returns a String (which indicates which View to display next). For "click on link/button in dataTable, you should wrap your table's Model Data in a DataModel object, which will decorate it with some necessary infrastructure. Then, when your (proper!) action method is fired, it can easily determine which row was selected by using the DataModel's getCurrentRow() or getRowIndex() methods. The action method is supposed to be indicated by a reference (action="#{studentController.addStudent}") not a "call". Putting an explicit method call in an EL expression may cause it to be invoked at the wrong point in the JSF lifecycle.

OK, enough nitpicking. I've discovered that JPA can often demand a transaction for things that you wouldn't consider transactional (like SELECTS). I've never found out why, just take it as a given.

Since you're not using an implicit transaction management framework such as Spring Data, that means that you're going to have to wrap your database operations in explicit getTransaction/begin/commit/rollback calls.

Finally, I've seen indications that when you create a backing bean using NetBeans, the name it gives ends with "Controller". This is a lie. Backing beans are Models. Controller logic in JSF resides in the FacesServlet and in the tag library implementations. Unless you're creating a custom tag using low-level logic in JSF, you never write Controller logic in JSF. You create Models and View Templates only. I think some of the confusion may be because backing beans can contain Action Methods, but Action methods are not Controller code. Controllers move data values between Model and View. Action methods see data already updated in the Model. Action methods are more properly classified as "business logic" and are invoked after all Controllers update the bean and before Controllers post any action updates to bean properties back to the View. So a Backing Bean is an impure Model (with business logic), but never a Controller.