Raible's Wiki: CreateManager

In the context of AppFuse, this is called a Manager class. Its main responsibility is to act as a bridge between the persistence (DAO) layer and the web layer. It's also useful for de-coupling your presentation layer from your database layer (i.e. for Swing apps). Managers should also be where you put any business logic for your application.

Let's get started by creating a new ManagerTest and Manager in AppFuse's architecture.

Create a new ManagerTest to run JUnit tests on the Manager [#1]

This class should extend BaseManagerTestCase

, which already exists in the service package. The parent class (BaseManagerTestCase) serves similar functionality as the BaseDaoTestCase.

The code below is what you need for a basic JUnit test of your Manager. Unlike the DaoTest, this test uses jMock

to isolate the Manager from its dependencies and make it a true "unit" test. This can be very helpful because it allows you to test your business logic w/o worrying about other dependencies. The code below simply sets up the Manger and its dependencies (as Mocks) for testing.




package org.appfuse.service;



import java.util.List;

import java.util.ArrayList;



import org.appfuse.dao.PersonDao;

import org.appfuse.model.Person;

import org.appfuse.service.impl.PersonManagerImpl;



import org.jmock.Mock;

import org.springframework.orm.ObjectRetrievalFailureException;



public class PersonManagerTest extends BaseManagerTestCase {

    private final String personId = "1";

    private PersonManager personManager = new PersonManagerImpl();

    private Mock personDao = null;

    private Person person = null;



    protected void setUp() throws Exception {

        super.setUp();

        personDao = new Mock(PersonDao.class);

        personManager.setPersonDao((PersonDao) personDao.proxy());

    }



    protected void tearDown() throws Exception {

        super.tearDown();

        personManager = null;

    }

}

Now that you have the skeleton done for this class, you need to add the meat: the test methods to make sure everything works. Here's a snippet from the DAO Tutorial tutorial to help you understand what we're about to do.




    public void testGetPerson() throws Exception {

        // set expected behavior on dao

        personDao.expects(once()).method("getPerson")

            .will(returnValue(new Person()));

        person = personManager.getPerson(personId);

        assertTrue(person != null);

        personDao.verify();

    }



    public void testSavePerson() throws Exception {

        // set expected behavior on dao

        personDao.expects(once()).method("savePerson")

            .with(same(person)).isVoid();



        personManager.savePerson(person);

        personDao.verify();

    }    



    public void testAddAndRemovePerson() throws Exception {

        person = new Person();



        // set required fields

        person.setFirstName("firstName");

        person.setLastName("lastName");



        // set expected behavior on dao

        personDao.expects(once()).method("savePerson")

            .with(same(person)).isVoid();

        personManager.savePerson(person);

        personDao.verify();



        // reset expectations

        personDao.reset();



        personDao.expects(once()).method("removePerson").with(eq(new Long(personId)));

        personManager.removePerson(personId);

        personDao.verify();



        // reset expectations

        personDao.reset();

        // remove

        Exception ex = new ObjectRetrievalFailureException(Person.class, person.getId());

        personDao.expects(once()).method("removePerson").isVoid();            

        personDao.expects(once()).method("getPerson").will(throwException(ex));

        personManager.removePerson(personId);

        try {

            personManager.getPerson(personId);

            fail("Person with identifier '" + personId + "' found in database");

        } catch (ObjectRetrievalFailureException e) {

            assertNotNull(e.getMessage());

        }

        personDao.verify();

    }

This class won't compile at this point because we have not created our PersonManager interface.

Create a new Manager to talk to the DAO [#2]

First off, create a PersonManager.java interface in the src/service/**/service directory and specify the basic CRUD methods for any implementation classes. I've eliminated the JavaDocs in the class below for display purposes. The setPersonDao() method is not used in most cases - its just exists so the PersonManagerTest can set the DAO on the interface.




package org.appfuse.service;



import org.appfuse.model.Person;

import org.appfuse.dao.PersonDao;



public interface PersonManager {

    public void setPersonDao(PersonDao dao);

    public Person getPerson(String id);

    public void savePerson(Person person);

    public void removePerson(String id);

}

Now let's create a PersonManagerImpl class that implements the methods in PersonManager. To do this, create a new class in src/service/**/service/impl and name it PersonManagerImpl.java. It should extend BaseManager and implement PersonManager.




package org.appfuse.service.impl;



import org.appfuse.model.Person;

import org.appfuse.dao.PersonDao;

import org.appfuse.service.PersonManager;



public class PersonManagerImpl extends BaseManager implements PersonManager {

    private PersonDao dao;



    public void setPersonDao(PersonDao dao) {

        this.dao = dao;

    }



    public Person getPerson(String id) {

        return dao.getPerson(Long.valueOf(id));

    }



    public void savePerson(Person person) {

        dao.savePerson(person);

    }



    public void removePerson(String id) {

        dao.removePerson(Long.valueOf(id));

    }

}

One thing to note is the setPersonDao() method. This is used by Spring to bind the PersonDao to this Manager. This is configured in the applicationContext-service.xml file. We'll get to configuring that in Step 3[3]. You should be able to compile everything now using "ant compile-service".

Now you need to edit Spring's config file for our services layer so it will know about this new Manager.

Configure Spring for this Manager and Transactions [#3]

To notify Spring of this our PersonManager interface and its implementation, open the src/service/**/service/applicationContext-service.xml file. In here, you should see a commented out definition for the "personManager" bean. Uncomment this, or add the following to the bottom of this file.

The "parent" attribute refers to a bean definition for a TransactionProxyFactoryBean

that has all the basic transaction attributes set.

Run the ManagerTest [#4]

Save all your edited files and try running ant test-service -Dtestcase=PersonManager.

Next Up: Part III: Creating Actions and JSPs - A HowTo for creating Actions and JSPs in the AppFuse architecture.

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Table of Contents

Create a new ManagerTest to run JUnit tests on the Manager [#1]

Create a new Manager to talk to the DAO [#2]

Configure Spring for this Manager and Transactions [#3]

Run the ManagerTest [#4]