Making Progress

In my last post, I lamented how difficult it is to unit test the Persistence layer.  My problem revolves around creation of a valid EntityManager.  Today, I revisited Joerg Gross' DevBlog entry "JPA Unit test setup with NetBeans". This time, I worked through each step of his sample code and managed to get my test case to compile and successfully instantiate an EntityManager.

But what was even more useful, was that the failures in instantiating the EntityManager clearly identified several issues with my Entity classes.  Now that I've finally got the EntityManager working, I can move on to actually building test cases.  Stay tuned.

In my implementation, I did two things differently from Mr. Gross.  First, I don't have a web tier, so the reference to /WEB-INF/classes/ in the build file isn't relevant.  Also, I didn't create an orm.xml file. 

Here is the code as I implemented it:

In the Test class:

  @BeforeClass
  public static void setUpClass() {
    /* Code adapted from
     *  Author: Joerg Gross
     *  Title: DevBlog "JPA Unit test setup with NetBeans"
     *  URL: http://eercp.blogspot.com/2011/12/ide-setup-with-netbeans.html
     */
    Properties props = new Properties();
    props.put("javax.persistence.transactionType", "RESOURCE_LOCAL");
    props.put("javax.persistence.jtaDataSource", "");
    props.put("javax.persistence.nonJtaDataSource", "");
    props.put("eclipselink.jdbc.driver", "org.apache.derby.jdbc.EmbeddedDriver");
    props.put("eclipselink.jdbc.url", "jdbc:derby:testDB;create=true");
    props.put("eclipselink.jdbc.user", "");
    props.put("eclipselink.jdbc.password", "");
    props.put("eclipselink.ddl-generation", "drop-and-create-tables");
    props.put("eclipselink.logging.level", "INFO");

    try{
    em = Persistence.createEntityManagerFactory("BirdDogDataPU",props).createEntityManager();
    } catch(PersistenceUnitLoadingException e){
      System.out.println(e.getMessage());
      throw e;
    }

  }

In the build-impl.xml file:

On a slightly different note:
Does anyone else ever enter their password into the username field? About 20% of the time, my login pages will open without the username auto-populated and I automatically start typing my password, oblivious to the fact my cursor is in the wrong place. Have you ever done this?  No, just me. Yeah, I figured as much.

Unit Testing JPA is Painful!!!

So, I decided since I'm rebuilding my BirdDog app from scratch, I'd take the time at each tier to implement thorough unit testing.  Should be easy enough, right.  Not so much.  First, there isn't any automatic help in NetBeans (or anywhere else it seems) for creating the necessary persistence objects in order to test the entity classes.  It is easy to create the JUnit Test classes, though.

So, I went in search of some help.  So far, I've found a few promising web pages.  I had a few bumps, but one thing remains broken.  I can't get the EntityManager to create properly.  UGH!!!!

Here is my current error:
Could not initialize class org.looman.birddog.data.test.PersistenceHelper.

PersistenceHelper is a static class for setting up a test database in Derby and creating the EntityManager.  Here's the code that's failing:

  private static final EntityManager entityManager;
  static {
    Properties props = new Properties();
    props.put("javax.persistence.transactionType", "RESOURCE_LOCAL");
    props.put("javax.persistence.jtaDataSource","");
    props.put("javax.persistence.nonJtaDataSource", "");
    props.put("eclipselink.jdbc.driver", "org.apache.derby.jdbc.EmbeddedDriver");
    props.put("eclipselink.jdbc.url", "jdbc:derby:testDB;create=true");
    props.put("eclipselink.jdbc.user", "");
    props.put("eclipselink.jdbc.password","");
    props.put("eclipselink.ddl-generation", "drop-and-create-tables");
    props.put("eclipselink.logging.level", "INFO");
    entityManager = Persistence.createEntityManagerFactory("BirdDogDataPU").createEntityManager();
  }

[EDIT 11-Apr-2014: I found a great source for formatting the code to make it more readable as code.  This is an implementation of SyntaxHighlighter by Alex Gorbatchev. David Craft provided easy to follow instructions for using this on his blog, CraftyFella's Blog.]

These are the two pages I found most useful.
Unit Testing your Persistence Tier code - By Neil Buesing on Nov. 9 2010
DevBlog: JPA Unit test setup with NetBeans - Joerg Gross

I'm done for the night.  Hopefully, the light will shine on soon.

On a slightly different note:
If anyone is following this, I have a question for you.  Would it be beneficial for me to upload my code into SourceForge?  Personally, I don't need the version control, etc.  However, if people are interested in seeing the code or helping me learn, then I'll go through the trouble of creating a project.  You have to reply in the comments and let me know you'd like to see this.

Good night.

Upgrading to NetBeans 8

I upgraded to NetBeans 8 a couple days ago and so far, I am really enjoying the changes.  One of my favorites is not well advertised and probably won't appear on anyone else's Top New Features List.

The refactoring in variable renaming is much improved.  First, when you rename an inner variable, you have the option of renaming all the associated Getters and Setters.  That alone is a significant time saver for me.

The second feature I've noticed in refactoring variable names happens in JPA Entity classes.  Relationships between classes depend on the inner variable names.  In the past when I changed the names, I would often forget one or two of the related class references and my code would fail.  Then I would spend hours trying to find the problem, because the log files weren't very clear on the problem.  Now, when you refactor a variable name in one class, the "MappedBy" value in the related class is updated automatically, removing one of my most common nemeses in debugging.

If you're interested in the new NetBeans IDE, you can download it here.  There are certainly enough new features to warrant the upgrade.  If you're new to NetBeans, I recommend it.  The learning curve is quick, better than Eclipse or JDeveloper, and the NetBeans Platform for developing Rich Client apps is a great time saver.