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Hibernate in Action 220

Posted by timothy from the go-to-sleep dept.
Adrian Spinei writes "From a documentation point of view, Hibernate is one of the most notable exception in the world of LGPL'ed projects. Its website offers a plethora of information, from solid documentation (the reference has no less than 141 pages) and various FAQs to sample projects and third-party resources. The forum is quite active and you may get answers to tricky questions. Or a little bit of rough treatment in case you haven't RTFM - but that is understandable, given the number of questions that the authors have to answer every day. Under these circumstances, one might wonder what Gavin King (Hibernate founder) and Christian Bauer (documentation/website maintainer and Hibernate core developer) can add in order to be able to write a 400-pages book about Hibernate. I mean - sure - only by joining the reference documentation, different FAQs and guides, one can easily 'extract' a hefty 'manuscript' with more than 200 pages." Read on for Spinei's review of Hibernate in Action.
Hibernate in Action
author Christian Bauer and Gavin King
pages 400
publisher Manning
rating unavoidable
reviewer Adrian Spinei
ISBN 193239415X
summary ORM pour les connaisseurs

Well, I am glad to tell you that this is not just a dump of the on-line docs. The book not only gets you up to speed with Hibernate and its features (which the documentation does quite well). It also introduces you to the right way of developing and tuning an industrial-quality Hibernate application. I consider myself a pretty seasoned Hibernate developer, being familiar with the API since its 1.2 version in Q1-2002 (if I remember well the first app when we used Hibernate). However, I was proved wrong by Hibernate in Action, which describes best practices and even API features that were unknown or vaguely known to me. That is, until now.

The first chapter, in the good tradition of all first chapters in the world, is an introduction. It's a very well written introduction about why do we need ORM solutions in OO applications. The chapter explains the O/R impedance mismatch, while declaring quickly that OODB sucks (immature and not widely adopted). Wel'll also find out that EJB also sucks from a persistence point of view (for various reasons). Which can be quite a surprise knowing that Gavin is one of the authors of EJB3.0 specs. Or, on the contrary, this will explain a lot of things in the new EJB specs.

Now that we have cleared the "why Hibernate" issue, let's continue to the second chapter. Which - tradition obliged - is a "Hello, world" and a "Let's get started" chapter. Here you go: almost 50 pages later you should be able to write simple Hibernate-based persistence layers and integrate within an application server, like for instance ... Jboss ! Humm, well, why not ? They are sponsors of the Hibernate project, after all.

In the 3rd chapter, our fresh knowledge will be put to good use by starting the development of an online auction application called CaveatEmptor. This app will follow our reading progression and will grow bigger and smarter chapter by chapter. But for the moment, we are at the inception phase. What gives: a little bit of analysis, a stylish class diagram of the domain model and the resulting mapping file. And if you thought (based on 2nd chapter) that the mapping file is very intuitive and simple, you're in for a big surprise -- it is, indeed, intuitive and simple! Quite bizarre for an open-source project. As a matter of fact, the mapping file is one of the pivotal elements of Hibernate, since it addresses directly the O/R impedance mismatch, a recipe for transparent linking your POJOs and the constrained relational model. No wonder that a big part of this chapter is aimed at explaining why and how the mapping works in Hibernate. You'll see how class associations and inheritance translate at the metadata and mapping level. You'll start to understand the things that you took for granted in the previous chapter and you'll have that pleasant "uuh, I see" chain reaction. Hold on, it's just the beginning.

Because chapter 4 is going to explain once and for all the lifecycle of persistent object in Hibernate, their behavior from a persistence point of view as well as the available fetching strategies. And if you thought you already knew everything by heart from the documentation ... well, maybe you do know everything by heart. Nevertheless, it's very well synthesized in chapter 4 and I'll recommend it anytime to a coworker eager for Hibernate knowledge.

In the next chapter (the 5th) the rollercoaster slows down a bit. That is, if you already know the behavior associated with the four possible isolation modes in transactions, what are the different types of locking, what (the hell) MVCC means and the importance of transaction scopes. Chances are you already know some of this stuff quite well, but everybody needs a refresher from time to time, especially when it's well explained and when it comes with versioning and caching (1st and 2nd level) in Hibernate as a desert. By the way, I thought that OSCache supports clustering, not only SwarmCache and JbossCache, as stated in the book. There's even a thoroughly explained example of using JbossCache as a level 2 clustered cache for Hibernate, but it shouldn't be too hard to convert to other types of caching systems.

Now, if I were the author of the book, I would have placed chapter 6 before chapter 5. But I am not the author, which is quite fortunate for you dear readers since Christian and Gavin are much more competent than me at writing books about Hibernate (and probably at some other unrelated domains). They have decided to go back to mapping in chapter 6, after the short transaction/caching intermezzo. Well, they should know better... it's time for a serious dose of advanced mapping. This chapter is attacking interesting subjects such as custom mapping types (simple or composite) and (finally) the mapping of collections. Special guests stars: the whole gang of "sets, bags, lists and maps", together with explanations about their relational equivalent (associations, associations and associations !). Oh and yes "polymorphic association" (section 6.4.3) - I wasn't even aware that Hibernate is able to do that... guess I'm not that 'seasoned' (as a Hibernate developer) after all.

The 7th chapter is about "Retrieving objects efficiently" : about 45 pages for the 'retrieving' part and 6 pages for the 'efficiently' part. Fair enough ! You'll learn how to master basic HQL queries (parameters, pagination ...). You'll get a grip on the query by criteria API, as well as on advanced stuff such as dynamic queries, filters, subqueries and native SQL (very powerful). At the end of the chapter there's the Hibernate-specific solution for the n+1 selects problem, query caching and result iterators.

Following this wealth of useful knowledge, the 8th chapter starts a bit dry. Nevertheless, after a short introduction about Hibernate in managed environments, you'll find yourself again in the land of advanced programming techniques : application-level transaction implementation ! This is mostly new stuff (at least for me) - a great collection of best practices for transactional behavior management in industrial-quality apps. Somewhat unrelated but still interesting, the chapter ends with legacy schemas integration and a smart implementation example for audit logging.

The 9th (and last) chapter is about the round-trip development in Hibernate using the classical toolset : Middlegen and/or hbm2java and/or XDoclet. All the available techniques are presented in a very detailed, step-by-step manner.

Wait : don't close the book, there's more ! Ignore Appendix A (a short and rather uninteresting document about SQL fundamentals - that is, if you know SQL). Appendix B contains mildly un-fascinating ORM implementation strategies pour les connoisseurs (come on guys, I'm just a dumb user). But - Appendix C is a great collection of real-world stories and by all means read them all ! Especially the last one, a treasure of hard to find knowledge (no spoilers, please...).

In the end, I have to confess that there is something truly interesting about Hibernate In Action : albeit very technical, it reads astonishingly easy - and this kind of books is unfortunately very rare nowadays. My congratulations to the authors for this excellent piece of work - it was worth the wait.

As for you dear potential reader, if you already know all the information detailed in the book, I bow before you, great Hibernate wizard.

You can purchase Hibernate in Action from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
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Hibernate in Action More

Hibernate in Action

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  • well, I overslept Sunday morning, does that count?

    CBV*()$#

  • What is Hibernate ? (Score:5, Insightful)

    by a3217055 ( 768293 ) on Monday October 11, 2004 @02:07PM (#10495285)
    What is Hibernate and what does it do ? I think the article failed to mention that can anyone please tell me what it means.

    Johnny English

    • Re:What is Hibernate ? (Score:5, Funny)

      by Dan East ( 318230 ) on Monday October 11, 2004 @02:10PM (#10495343) Journal
      All you need to know is it is well documented, in the event that you ever actually need to know.

      Dan East

    • Re:What is Hibernate ? (Score:5, Informative)

      by Jouser ( 243992 ) on Monday October 11, 2004 @02:10PM (#10495347) Homepage
      From hibernate.org through google's cache:

      Working with object-oriented software and a relational database can be cumbersome and time consuming in today's enterprise environments. Hibernate is an object/relational mapping solution for Java environments. The term object/relational mapping (ORM) refers to the technique of mapping a data representation from an object model to a relational data model with a SQL-based schema.

      Hibernate not only takes care of the mapping from Java classes to database tables (and from Java data types to SQL data types), but also provides data query and retrieval facilities and can significantly reduce development time otherwise spent with manual data handling in SQL and JDBC.

      Hibernate's goal is to relieve the developer from 95 percent of common data persistence related programming tasks. Hibernate adapts to your development process, no matter if you start with a design from scratch or work with a legacy database. Hibernate generates SQL for you, relieves you from manual result set handling and object conversion and keeps your application portable to all SQL databases. Hibernate provides transparent persistence, the only requirement for a persistent class is a no-argument constructor. See our list of frequently asked questions about Hibernate.

      Hibernate is typically used in Java Swing applications, Java Servlet-based applications, or J2EE applications using EJB session beans. See this page for an overview of Hibernate application architecture.
    • The link they left out(tm): http://www.manning.com/bauer

    • Re:What is Hibernate ? (Score:5, Informative)

      by jonathanduty ( 541508 ) on Monday October 11, 2004 @02:11PM (#10495366) Homepage
      Hibernate is a Java persistance layer. Basically, you can map java objects to a database schema (doesn't matter which one comes first). If I have a table called "user", I can create a java class called "user" (or whatever I want to name it) and use that class to access the database, without writing any sql. I've used a few different persistance frameworks and Hibernate is at the top of the game for now. If you are writing a java app that will access a database I highly suggest you take a look at it. Pure JDBC still has its place in the world, but Hibernate tends to make life a lot easer (and less messy).

      • Re:What is Hibernate ? (Score:5, Informative)

        by Tailhook ( 98486 ) on Monday October 11, 2004 @02:41PM (#10495681)
        (doesn't matter which one comes first)

        Actually, it does matter which comes first. Hibernate works best (best defined as most clean, simply) if you have the luxury of a well normalized schema where every table contains a surrogate key. Obviously, if you're working from a clean sheet this is an worthy design choice, relatively easy to satisfy.

        However, if you are working with a pre-existing design and you can't retrofit surrogate keys, you're in for a lot of additional leg-work with Hibernate. Getting Hibernate to function with composite keys forces extra coding and imposes limitations. This was my experience 9 months ago when I had a look at Hibernate for an "enterprise" application that must work with vendor schemas.

        I don't fault Hibernate; persistence is hard. Mapping an object from RAM to relational storage is much easier when you have a simple 1-to-1 relationship between objects and integers. Working well only with simple surrogate keys is not unique to Hibernate by any means. In principle you're correct; it doesn't matter which comes first. In practice, if you're dealing with composite keys or any form of denormalization you're in for a lot of pain.
        • Actually, compositite keys have been supported by Hibernate beginning with version 2.0, which came out over a year ago. See here [hibernate.org].

          Usually, problems with mapping existing database schemas to Hibernate arise from the shorcomings of the database and not Hibernate. Oracle's CLOBs and BLOBs are a good example of this, as the methods exposed by the JDBC interface do not work properly and methods from Oracle's CLOB and BLOB classes must be used directly, breaking transparency and forcing the developer to do add

      • Our company tried similar (closed-source) software. It was called Cocobase, but I don't really remember the company's actual name, if that was it. Five releases, one year, and countless problems later, it's still being yanked from our code. There were a few too many whacked out exceptions, objects not being updated, and places where code and schemas trying to talk to each other didn't agree. We reverted to basic JDBC, and I'm not really sure we're going to go back anytime soon while object mapping and persi

      • Re:What is Hibernate ? (Score:3, Informative)

        by JASegler ( 2913 )
        I've had the misfortune to inherit a project that was written by someone who believed Hibernate is a persistence layer.

        Hibernate is tempermental at best and broken at worst. The biggest problem is it has it's own special language called HSQL which gets converted into SQL at runtime.

        HSQL is supposed to be database neutral. However, things don't work the way they are supposed to all the time. Specifically CLOB/BLOBs on DB2 for OS390 crash the OS390 JVM. Other things fail (sometimes silently) in unexpect
        • Just don't think it will magically do all the hard things like tracking updated/deleted/new objects, cascading auto generated keys from parent to child (or child to parent if your tables swing that way) or sequence delete/update/inserts to avoid referential integrity problems. Funny...hibernate did *all* of those things for me...

    • Re:What is Hibernate ? (Score:4, Informative)

      by grunt107 ( 739510 ) on Monday October 11, 2004 @02:12PM (#10495376)
      Hibernate is purported to be a persitent object programming tool.

      This was grabbed off www.onjava.com:
      Hibernate will help us to painlessly store the data in permanent storage without too much hassle about choosing the kind of storage, installation, or configuration. Hibernate allows us to store any kind of objects; therefore, our application does not need to know that its data will be persisted using Hibernate. Of course, everything mentioned here can be applied in the opposite direction: fetching already prepared objects from a storage is now nearly trivial. Updating and deleting data is also available.

      Judging by their inaccessible website, Hibernate is what they do best.

    • The overview tells us nothing (Score:5, Insightful)

      by frovingslosh ( 582462 ) on Monday October 11, 2004 @02:45PM (#10495721)
      Another lame /. article; what supposedly is an "overview" tells us nothing and is so full of TLA and such that you have to know what they are talking about to even make any sense of it. Clue for timothy: If you're introducing something new in a lead page /. article, it would be nice to actually tell people what it is, cutting through three letter acronyms and other buzzwords that can only be understood in context , which is missing when the reader has no reasonable expecation of knowing what the hell you are talking about!!!
    • I certainly agree. They could have mentioned what it is (something to do with making Java have data persistance). I would think to 90% of Slashdot readers "hibernate" is something laptop computers do when you close the lid.

  • A 400 page manual? (Score:5, Funny)

    by Weaselmancer ( 533834 ) on Monday October 11, 2004 @02:08PM (#10495299)

    Jeez, with a manual that big it should be named coma.

  • Hibernate is good, but I am using Prevayler more (Score:5, Informative)

    by MarkWatson ( 189759 ) on Monday October 11, 2004 @02:08PM (#10495315) Homepage
    Hibernate is a very solid Java object relational mapping tool (I have a section on Hibernate in my last book). When you need OO to relational database mappings, Hibernate is my recommended tool, for sure.

    However, for my Java consulting business, Prevalyer [prevayler.org] is definitely my new "secret weapon". With a little care, it is easy to set up your POJO classes so that you can add class attributes without breaking your persistent Prevayler object store. Using Prevayler reduces development time. Good stuff.

    • I still prefer directly writing the SQL code myself. It doesn't take that long, and for many things it seems to be more efficient. I only pull the fields that I need.

      I have seen many applications where a developer will pull a list of objects out of a database and only use a small percentage of what was pulled. This was caused by a heavy persistence layer abstracting what was happening, and a developer that didn't care to find out.

      I seem to be in the minority with this view though. Automated persistence is quite trendy.

    • Re:Hibernate is good, but I am using Prevayler mor (Score:5, Funny)

      by smcdow ( 114828 ) on Monday October 11, 2004 @02:30PM (#10495569) Homepage
      Hibernate is a very solid Java object relational mapping tool (I have a section on Hibernate in my last book). When you need OO to relational database mappings, Hibernate is my recommended tool, for sure.

      However, for my Java consulting business, Prevalyer is definitely my new "secret weapon". With a little care, it is easy to set up your POJO classes so that you can add class attributes without breaking your persistent Prevayler object store. Using Prevayler reduces development time. Good stuff.

      Good Lord.
      This post, while informative, just makes me want to go to sleep. Or quit my job. Or both.
      Maybe I chose the wrong career.
      Are Java class mappings to databases really all that exciting?

    • No offense, but the Prevayler site is pretty lame. I'm quite sure it's fast, but anybody who's written an in-memory system before knows that. Whenever your working data set is small enough to fit in memory, and your transactionality requirements force you to serialize processing at the application level anyway, your performance will be much better with a simple object-in-memory design.

      Anyway, the point is the site doesn't do anything to elucidate the limitations on ACID compliance, querying capabilities

  • What is it? (Score:3, Insightful)

    by DaHat ( 247651 ) on Monday October 11, 2004 @02:09PM (#10495320)
    It always drives me nuts when I see a story about a given software package that talks about it's greatness... but that does not simply say what it is. This is made worse when the it's homepage which I'm sure describes the given package is /.ed.

  • By the way, if you've never heard of Hibernate... (Score:5, Informative)

    by Palshife ( 60519 ) on Monday October 11, 2004 @02:09PM (#10495326) Homepage
    I really wish the story submitter would have taken a moment and put a one or two sentence explanation of what Hibernate is. It's not exactly a descriptive name, which I'll concede is common in our industry.

    Hibernate is an API for Java that uses Java Beans (get() and set() methods for all properties) to create, read, update and delete rows from a database. It's really cool. It's sometimes called JDO (Java Data Objects) but it's a dangerous association because of the Sun Reference Implementation of JDO, which is its own specification. Hibernate is different.
    • It is a bit ironic that some of the space the reviewer devoted to raving about the completeness of the Hibernate documentation could have been instead used to explain what the hell the software is. First I figured it was some sort of APM/ACPI module, then a documentation tool then I hit "The chapter explains the O/R impedance mismatch..." and gave up entirely.

      (Ok, maybe it's not ironic. After all the flaming from irony-obessed pedants, I have no idea anymore. But it's at least as ironic a rain on your weddi

    • I think you oversimplified hibernate. Its an ORM. Its built to read xmls of files that map object fields to database columns (including complex relationships, such as one-to-many and many-to-many). Once that is done, persisting data to the database is quite simple with hibernate.

  • book better than review, I hope (Score:5, Insightful)

    by Russ Nelson ( 33911 ) <slashdot@russnelson.com> on Monday October 11, 2004 @02:09PM (#10495332) Homepage
    I hope that the book is better than the review. The reviewer starts off with the most basic assumption that ANYBODY with a CLUE knows EXACTLY what Hibernate is. Perhaps that's why hibernate.org isn't responding right now, because everybody read the top story, found no description of Hibernate, and clicked on the hibernate.org URL as the most likely place to find a description of Hibernate.
    -russ

  • whaa? (Score:2, Funny)

    by josh crawley ( 537561 )
    This article just seems like a bunch of open source NewSpeak, I swear to god every time I try to read and understand what this is about my brain shuts down... quack quack RTFM quack quack OODB quack LGPL...

    • MOD PARENT UP (Score:4, Insightful)

      by hopethishelps ( 782331 ) on Monday October 11, 2004 @04:36PM (#10496873)
      This article just seems like a bunch of open source NewSpeak,

      You're right, there is no information in the article. It doesn't even tell us what Hibernate is. The blather is also peppered with undefined acronyms - ORM, POJO, HQL.

      And some idiot moderator modded parent down as a troll. Sigh. It's not a troll, it's a valid and accurate criticism of a really crap article. Crap is, unfortunately, becoming the Slashdot-article standard.

  • Why hibernate? What's hibernate? (Score:4, Funny)

    by Hatta ( 162192 ) on Monday October 11, 2004 @02:10PM (#10495344) Journal
    It's a very well written introduction about why do we need ORM solutions in OO applications. The chapter explains the O/R impedance mismatch, while declaring quickly that OODB suck (immature and not widely adopted). Wel'll also find out that EJB also suck from a persistence point of view (for various reasons). Which can be quite a surprise knowing that Gavin is one of the authors of EJB3.0 specs. Or, on the contrary, this will explain a lot of things in the new EJB specs.

    Now that we have cleared the "why Hibernate" issue,

    Yeah... Cleared that right up. ORM? O/R Impedence? OODB? EJB? Little help here?

  • Pardon my ignorance... (Score:3, Funny)

    by Saint Aardvark ( 159009 ) * on Monday October 11, 2004 @02:11PM (#10495352) Homepage Journal
    but Hibernate's website is Slashdotted, and this review gives me no clue about what Hibernate might be.

    Rather than sharing my theories about a top-secret-yet-LGPLd government project to develop object-oriented Java-based SQL/graphics library that will allow us to train secret UFO pilots to defeat an invasion of alien accountants, would someone care to fill me in? I would be forever in your debt.

  • I mean mispellings in the comments is one thing, but if you are submitting an article for posting, spell check it! Jeez...I stopped reading once i hit "recipy"

  • Curious why there's not more. (Score:3, Insightful)

    by Amiga Lover ( 708890 ) on Monday October 11, 2004 @02:13PM (#10495379)
    I think it's interesting there's not more really exceptional documentation for F/OSS projects.

    OSS Coders tend to have the fantastic attitude of always improving whats been written before, of making it better & better, revising, patching, rewriting, until an application becomes so damned useful there doesn't seem to be any other realistic choice.

    All well and good when it comes to coding - but where are all the documentation geeks to do likewise?
    • Many GNU programs are very well documented, such as Emacs/XEmacs, gcc, glibc, gmp (a multi-precision computing library), gsl (GNU Scientific library). Just read the info page, or if you want something prettier, grab the TeXinfo files in the source package and make a PDF version.

      It depends on the popularity... if a library becomes very widely used, its documentation will improve by itself. GTK documentation had been almost nonexistent during the 1.x days (just a tutorial), but now it is mostly acceptable

  • Usually I am able to BS my way through an article by making a guess based on the title. This article. however, posed a problem to me... I couldn't figure it out, or rather the decision I made wasn't that logical.

    Based on the info in the title, I concluded that the project did nothing (after all, a successul implementation of hibernation just sits there.) This caused me much confusion, resulting in me mistaking salt for sugar, and baking soda for non-dairy creamer....

    ...Remember kids, think before you p
  • Comment removed based on user account deletion

  • Another project with a lot of Documentation (Score:4, Funny)

    by Necroman ( 61604 ) on Monday October 11, 2004 @02:21PM (#10495470)
    "The R Project for Statistical Computing"

    http://www.r-project.org/ [r-project.org]

    This is an amazing stat program that is open source with a lot of documentation backing it up.

    Some of the documentation you can download:
    An Introduction to R (approx. 100 pages, 650kB)
    The R Reference Index (approx. 2300 pages, 12MB)

    Also, under their contributed documentation section, they have the documents sepearted by "Documents with more than 100 pages" and "Documents with less than 100 pages".

  • Is there a doc in the house? (Score:4, Insightful)

    by Doc Ruby ( 173196 ) on Monday October 11, 2004 @02:25PM (#10495509) Homepage Journal
    When people release source under L/GPL, you'd think they'd want people to use it, and contribute back. It's really hard to do that when the code is inaccessible for lack of documentation. Even reading code that is commented (a rarity) is no substitute for an overview - relying on "grep" is no way to trace codepaths or marshal APIs. At least CVS requires a note on checkin, even if it's usually a vague "fixed bugs". If you're not going to write your code starting with a first pass of all comments, with clear, consistent variable names, at least include a description of each code file's function in the grand scheme in its header, and usable README and INSTALL files for the whole project. Most important, have someone not on the design/code team read the docs for usability by a stranger. Beta testing the docs isn't hard, and you get to gloat about your brilliant achievements in words that don't have to compile.
  • So many initial posts asking what Hibernate is when it is probably the poster child of Java Open Source (OK JBoss might be better known but unlike JBoss Hibernate is universally well regarded). Disappointing really.

    • Re:I am a tad surprised (Score:3, Informative)

      by rudedog ( 7339 )
      So many initial posts asking what Hibernate is when it is probably the poster child of Java Open Source (OK JBoss might be better known but unlike JBoss Hibernate is universally well regarded). Disappointing really.

      It sounds like this may come as a complete surprise to you, but not everybody is a Java programmer. Why should non-Java programmers be expected to know about a Java-only tool?
    • Probably because the Java Open Source community has largely segregated itself from the rest of the free software/open source community by supporting only proprietary Java platforms.
      • It is not our job to workaround bugs in gcj etc. If our code fails due to a bug in gcj, it is the responsibility of users/developers of gcj to fix that, not ours. I have contributed bug reports to gcj but I don't see it as a major priority. I get paid to write code that works on the official Java platforms.

    • If Hibernate is your poster child, you need a new child. Or poster. Or analogy. OR maybe its like a child poster on a milk carton. Have you seen this technology? It was last sighted in 2001 shortly after its birth.
    • Hibernate is universally well regarded.

      After reading some of the comments on this article, I'm thinking this might be a bit of a stretch.

  • The R programming language [r-project.org] has excellent documentation [r-project.org], all written by the developers and users, including a newsletter [r-project.org] and some contributed documentation [r-project.org], including a little reference card [geocities.com] I wrote.

    The program is GPLed, and shows that excellent documentation is possible, if enough people.

  • Best thing since sliced bread (Score:5, Informative)

    by teutonic_leech ( 596265 ) on Monday October 11, 2004 @02:34PM (#10495598)
    I have used Hibernate on the last two J2EE projects I've worked on and can attest to its simplicity and power. Although it'll take you a few weeks to really get the hang of how things work under the hood, it's well worth the learning curve. And it's ridiculously simple compared with EJB - that's for sure. My latest project even involved storing CLOBs to an Oracle Rack cluser - it took a bit of tweaking and research, but we saved ourselves hundreds of lines of codes and it performs without a glitch.
    Okay, I haven't RTFA, but the poster should also have made mention of Spring, which works hand in hand with Hibernate. Spring basically is an Inversion Of Control (IOC) framework, that allows you to define Hibernate transaction and session contexts. Spring also offers a great MVC layer, but one does not have to use that. If one chooses to just use Spring as an addition to Hibernate, one can look at Spring's additional functionalities as needed. Spring also offers Oracle BLOB/CLOB support by offering a customized OracleClobHandler - Oracle ONLY supports its propietary CLOB objects and won't accept java.sql.Clob objects via Hibernate.
    Generally, Hibernate is very non-intrusive and gives you the opportunity to write JDBC code alongside with your Hibernate code (which is super-elegant and abstracted the way it should have been done a long time ago). So, it can be slowly folced into an existing project without having to refactor any legacy code.
    The Hibernate user group is a bit rude to be quite frank - I've tried to post some questions in the dev group and got pretty angry replies. The 'beginner' group was not very helpful, so I had to google for answers. Of course there's the book, and I would strongly recommend to get it, since it is one of the major revenue sources for those Hibernate contributors. We want open source, but we can't expect to get everything for free, right? ;-)
    My first exposure to Hibernate was through the Appfuse framework [raibledesigns.com], which is an excellent J2EE kickstart project, complete with ant built, Xdoclet, Hibernate, Spring, the works. I was even able to use XDoclet tags inside my Java beans, relieving me of having to write my Hibernate definition files by hand! It really doesn't get much easier than that. For anyone wanting to give Hibernate/Spring a try, I recommend to download the latest version of appfuse and give it a try - it's a liberating experience. The biggest kick I got was being able to seamlessly switch my project from Oracle over to MySQL by simply changing a few environment variables - I mean, how cooler can it get? :-)

  • Sufficient docs rare? (Score:4, Insightful)

    by ajs ( 35943 ) <ajs.ajs@com> on Monday October 11, 2004 @02:34PM (#10495605) Homepage Journal
    Hmmm, *looks on hard drive*...

    a 7000-word document on configuring ALSA drivers
    a 400,000-word document on using MySQL
    a 700,000-word documentation set for Perl (just the core, not counting add-on modules)
    6.5MB of Kernel docs
    27MB of Gnome help ... the list goes on, of course ...

    Nope, that's not a particularly outstanding trait. If he had talked about this documentation being well integrated with other, related documentation-sets, then I'd find that interesting (rarely is this the case in open source software), but it doesn't sound like it is.

  • What their server is doing right now.... (Score:4, Funny)

    by Matrix_X ( 145593 ) on Monday October 11, 2004 @02:39PM (#10495656)
    Hibernate is what their server is doing right now after the vicious slashdotting that it just received.

  • Hibernate in Action (Score:3, Funny)

    by Hard_Code ( 49548 ) on Monday October 11, 2004 @02:47PM (#10495756)
    Summary: zzzzzzzz

  • So, I'm the only one, huh? (Score:3, Insightful)

    by tokachu(k) ( 780007 ) on Monday October 11, 2004 @02:50PM (#10495792) Journal
    I thought "hibernate" was a power-management function.

    Actually, this entire article is proof of how...
    • ...program names are getting more pointless by the day (Hibernate?), and...
    • ...how most programs are mostly hype (more buzzwords than a Dilbert book).
    I'm sorry, but there's no excuse for the utter disregard to using common sense that was exhibited in the "hibernate" developers' group. People wonder why Microsoft can sell shoddy products. Well, I'll tell you why: they give them meaningful names (Word processing: WORD, Development studio: STUDIO).

    To the people at hibernate.org [hibernate.org]: you should be ashamed.
    • Right. When you can't find professional arguments against a perfectly usable and very nicely done project like Hibernate you start the old story on bad sw names.

      It's an old and boring disk alright, so not much use to start on that again.

      And no, I won't even start picking from the many dozen software names that don't have anything to do with their goals. Because I just don't really care. If you give me a usable tool you can call it pumpkin-pie-2k if you wish. It's your choice.

      Hell, does your name have
  • I'm working with Hibernate now and I desperately need to read the documentation to find out how to do something and you lot have gone and bloody /.ed the site.

    The doco is very good but I think some of it needs updating. A lot of it still refers to the hibernate.properties which I believe is deprecated in favour of xml configuration. For example I still haven't been able to get the SqlExport ant task to work with the xml conf even following the documentation - however I only tried for about 10 mins. I wil
  • ...or it's in hibernation...
  • With an all expenses paid server meltdown. That will teach them to have hundreds of pages of quality documentation on line.
  • I have used Hibernate and Spring on a number of projects. Hibernate, of course, provides the abiltity to build POJO Data Transfer objects similar to JDO and others. Spring provides everything else. Really Spring just facilitates AOP, IOC (like most containers) and the ability to swap out all common implementations for another easily (for testing, change in philosophy, etc.). Spring also provides a better MVC layer than Struts (arguably) but allows you to use Struts or any other MVC framework you like.
    • Check out Tapestry (part of Jakarta) for a much better web framework than Struts. Integrating these 3 frameworks results in a very nice architecture that allows you to write J2EE applications that can be very container-independent.
      Spring allows you to put together your UI code, your persistence code, and your business logic together, without the need to tie any layer to the other ones.
  • The first chapter, in the good tradition of all first chapters in the world, is an introduction. It's a very well written introduction about why do we need ORM solutions in OO applications.

    It's ironic that the reviewer acknowledges that introductions are a "good tradition" but then fails to write an good introduction himself . . . I like many had no idea what Hibernate is until I read some of the posts by gracious /.'ers that took the time to post a description of Hibernate. Additonally isn't it good wri

  • Anyway, I think we just sent their site into hibernation...

  • Hibernate is a superb product, but has some disadvantages: Firstly, it's a non-standard API. This may, or may not, influence a developer's decision to use it, but anyone looking at using an object-relational mapper might also look at JDO (Java Data Objects), which is a standard, and has many competing versions, both commercial and free. A new specification for JDO, version 2.0, is about to be published, which has most, if not all, the features of Hibernate, including many additional aspects which are uni
    • AFAIK, JDO 2.0 is based on Hibernate. The "new" query language that comes with JDO 2.0 is based on HQL (Hibernate Query Language). They did this because Hibernate is the most popular Java ORM out there, and this time I think it was a good decision to base the new standard on an existing open source framework, rather than reinventing the wheel and coming up with something lousy.
      I hope someday the EJB stuff becomes easier to deploy, maybe they can take some ideas from Spring, to allow for more container-ind
      • AFAIK, JDO 2.0 is based on Hibernate.

        It isn't. It has fundamental differences - cache management is different, there are many more object cache states (e.g. hollow) than in Hibernate.

        The "new" query language that comes with JDO 2.0 is based on HQL (Hibernate Query Language). They did this because Hibernate is the most popular Java ORM out there, and this time I think it was a good decision to base the new standard on an existing open source framework.

        There is no new query language with JDO 2.0 - its
  • Can anyone give an explaination of BPM and the Agila BPM engine and lend some insight into the significance of this?

    http://www.infoworld.com/article/04/10/04/40NNbl ue code_1.html

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