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Effective Java
Introduction
Effective Java is a book very much in the style of Scott Myers' earlier C++ "Effective" series. The book contains 57 individual snippets of Java wisdom, broadly categorised into 10 sections including Classes and Interfaces, Exceptions, Threads and Serialisation. Scott Myers' books are classics; I was interested to see how this would compare.
The author, Joshua Bloch, has been involved in writing many industrial-strength Java libraries. His background is very much evident, in this, his first text. He consistently demonstrates the virtues of favouring libraries, clean APIs and advance design. I found the author very readable, and able to make a convincing argument, even in his more 'controversial' pieces. As with Scott Myers' books, there is a real-world, rather than purist approach taken to the language, with most of the code examples having a real-world feel to them. This is a breath of fresh air when lots of programming books tend to use more contrived examples.
The items
The author has endeavoured to keep the book accessible to less-experienced programmers throughout, while providing food for thought for the more advanced reader. For the most part this is succesful, but a small percentage of articles tend toward the simple side. Examples include 'Minimise the accessibility of classes and embers,' 'Write doc comments for all exposed API elements,' and 'Know and use the libraries.' We've all heard this advice many times and I don't feel that these add value. The vast majority however, are pitched at the right difficulty level. The selection of items is well balanced and broad, although unfortunately there are none pertinent to GUI programming.
Many of the articles are fundamentally based on known design patterns and idioms. Although a useful index to these patterns is included, I would have liked to see the virtues of design patterns summarised and demonstrated to a greater extent, perhaps in the introduction.
I was highly impressed with all code examples. Where used, they are consistently short, relevant and concise, with more verbose examples included on the website. The chosen code examples only ever assist in explaining complex concepts clearly.
The strongest area of the book for me was the section on threading. The author clearly demonstrates, for instance, how overuse of synchronised methods can lead to deadlock. He also provides food for thought on how the thread scheduler might trip us up. A section on moving from C constructs, which initially struck me as an odd category, proved very interesting and thorough. 'Replace enum constructs with classes' is a particularly interesting item, demonstrating the fragility of C enums, and indicating why the often-used replacement in Java (a bunch of public static constants) suffers from the same failings.
In conclusion
Ideally I would have liked to see some of the thinner items removed, and perhaps replaced with a section on the GUI libraries. I also liked the short prose sections, and thought the author could have spent more time setting out his stall before launching in to the items. Having said this, this is one of those rare books which could help a good programmer become an excellent one. Many of the books currently out there are aimed at either the beginner or the guru, and this book fills a gap.
I find this style of book very useful, in that I could foresee meeting the vast majority of the described situations at some point or another. So long as you aren't looking for tips to help you with your GUIs, this title is more than worth the investment.
For anyone interested, those sections in full:
- creating and destroying objects
- methods common to all objects
- classes and interfaces
- substitutes for C constructs
- methods
- general programming
- exceptions
- threads
- serialisation
You can purchase Effective Java from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
Do not talk of this Java Sanctuary. There is no such thing.
J. Bloch wrote the collections framework. His code is clean... I mean, really clean. Given the author's credentials, I suspect this'll stand out in the vast ocean of Java lit...
having developed many effective applications for a few years using java, i can, with confidence respond that "Effective Java" is not a contradiction. i've found that most "java haters" are those whose experience goes no further than the applet. too bad sun ever conceived of that little painful abomination.
java is like any other language, its a tool to get your job done, and contrary to popular belief, it gets it done rather nicely.
of course i don't mean to wax religious here... there's enough of that here.
sad robot making broken music
Man, I'm barely done with Douglas Dunn's
Java Rules and now I gotta read this?
Actually, I'm glad to see more book son coding effectively as opposed to the dummy approach which is a sure way to Shoot yourself in the foot when the maintenance phase rolls around.
That said, one thing copiously missing from the review is whether or not the book covers J2EE at all -- which by and far requires some guidance in the developing the most effective Java applications.
--- have you healed your church website?
Have you actually used it lately? Speed has been the biggest improvement. Sure, it used to be slow as hell, I concur, but with Java 2 (1.4) it is wicked quick. And for windows apps, it's far better than VB in at least one aspect - grids. Java has a grid object that works the way you'd want it to, resizeable, sortable, column-rearrangeable... And for data drive apps, this is a major thorn out of my side.
How are you going to keep them down on the farm once they've seen Karl Hungus?
In a Windows dominated enviorment, is there any other better alternative to what I am already using?
.NET seems to work alot better than the hideous quivering zygote that is VB6, IMHO. In particular C#.
.NET. I'd also go with Java if your IT department had any plans to change platforms in the future. .NET and company allow MS to keep a string tied to your IT decisions unless you're willing to abandon your code.
The abortion that is
Really, I would say that it depends on the environment. If the back end is Oracle or DB2, I'd probably go with Java; if it's SQL Server I'd be more inclined to go with
I've found ODBC-style data access in Java to be only slightly less painful than doing it in Visual C++.
I'm in a similar situation, developing and maintaining a data access application in VB6 that has reached 'critical mass', has gotten too big for it's britches, and needs to be rewritten from the ground up.
I've been doing a lot of thinking about what it will be rewritten in, and so far C# and VB.net are leading the pack. All Java has to offer me is some platform independence, which is pretty much irrelevant in my particular case, and I doubt it would be worth headaches like throwing out all the code that's written.
Anyways, this is all contingent on the dorks in marketing not selling imaginary software that I have to write 2 weeks before shipping, that I may have time to make the actual software work.
I don't need no instructions to know how to rock!!!!
... is the Java 2 Performance and Idiom Guide (ISBN:0130142603), by Craig Larman and Rhett Guthrie.
The main things I hate about Java are its verbosity and its enforced and contrived structures.
Except that verbosity and (contrived?) structures goes a long way towards keeping source maintainable. By requiring this verbosity and not to mention strongly recommending the Sun Java coding standards + Javadoc, code becomes magnitudes easier to read. Sure, it adds work and a bit of pain to the original coder/programmer, but adds substantially more ease of use for those down the line. Don't get me wrong it's still very easy to write hard-to-read-and-or-maintain code, but it's a bit easier to go the correct route.
But if that's how you get your kicks, gagged and bound with Sun sticking it to you, then so be it...
That depends on what you are referring to. You are right that Sun tends to stick it to the end user now and then and ultimately Sun can be said to be Java's worst enemy. For example, Mac OS X trying to do some amazing things with Java showing how it can be used viably, getting very little support from Sun.
After all that's said, I too still prefer C++ (even C#) over Java, but just not for the reasons mentioned.
----- "Blame the guy who doesn't speak English." -- Homer J. Simpson
This book is the best resource I've encountered for someone who knows the Java language, but wants to master its use. I can virtually guarantee that the rules and techniques covered in "Effective Java" will form the new foundation on which you will build the rest of your best practices for writing excellent Java code.
Written by the Joshua Bloch, the acknowledged expert on the subject, it is as authoritative as they come and extremely well-written. After six and a half years as a senior developer architecting and implementing algorithms and class libraries in Java, this book shocked me by summarizing much of what I knew about how to use the language effectively, while teaching me much that I did not know. It continues to top my recommended reading list for all new software developers at my company.
-dk
Java is slow? Maybe that's just your coding. These guys (among others) don't agree with you...
http://www.sosnoski.com/Java/Compare.htmlhttp://www.javagrande.org/jgsc98/index.html
IBM has achieved 90% the speed of C in Java. I personally use the CERN numerical libraries ... very cool, very fast. Java certainly can be fast. I've seen distributed Java beat C++ implementations hands down (that was hard to everyone to believe ... problem was C++ CORBA marshalling and the RTTI overhead in C++).
I've used Squeak, and have a background in coding Smalltalk (Digitalk, ParcPlace, IBM VA). Squeak is a great up-and-coming environment, but FAR from commercial. Can you name one commercial implementation in Squeak?
I think that lack of commercial viability makes Squeak impractical. Java, on the other hand, has scads of drop-in commercial libraries and components. This makes economic sense in business. Java also has a proven track record on the server side, and there are many, many successful commercial implementations in mission critical environments.
And NO, I don't think Java is the perfect enviroment; far from it. I've yet to see my ideal language, and I keep looking on the horizon for a dynamic functional/object/aspect language that performs and holds up in a commercial setting. In the meantime, I've got real work to do.
There are a lot of Java books out there, but this is one that will help an intermediate-to-advanced Java developer. The code examples in here are concise, clean, and hard-hitting. The layout of the book allows you to pick it up and learn something if you have 10 minutes or 2 hours.
When I was first learning Java, I often had that nagging feeling that I was making things harder on myself than need be. This book cleared up a lot of those feelings, and helped get me on the right track for some of the great tools hidden away in the Java API. The API documentation is great for showing you what members and functions are available to an engineer, but this book shows you how to use the API. The review cites the author's avocation of knowing the libraries, I would contend that this book would help you get the most out of those libraries, and increase your understanding of them.
This book has become a must-have around my office, and if you are looking to get over-the-hump and move from an intermediate to advanced java software engineer, pick up this book. It is dense with information, and will save you a ton of time and energy. What more could you ask for from a book?
Effective Java is a book very much in the style of Scott Myers' earlier C++ "Effective" series
This is about the highest praise you can give a language-specific programming guide. In his books Scott not only listed many of the ways you could get in trouble in C++, but also gave clear explanations of why they were trouble and why his recommendations were good practices. His books are top of the list I recommend to people who know the language and want to write solid fast code. If Effective Java is as good, I'll soon be adding a copy to my bookshelf.
--Jim
What does 'setting out his stall' mean? I picture somebody settling on to the toilet and opening the newspaper, but in the context I don't think that's what you meant.
Thank you, a good review of an excellent book. I have maybe 10 java books, most of them from O'Reilly and none have been as beneficial to my development in Java as this one.
The code and the text are both very clear and concise, and you can read the book cover to cover, coming back later to study each advice more in depth.
I think you can get it from reading between the lines in the review, but just to make it clear to any curious beginner, this is not the first book you should buy if you are just starting to learn java. Use
The Java Tutorial instead, and maybe
Learning Java.
Being bitter is drinking poison and hoping someone else will die
What? Did I forget to include emoticons or tags? Did I not make the references to "Logan's Run" explicit enough? Sheesh. Flamebait.
This is a fantastic book, and anybody's who's serious about writing good Java code should study it carefully. It's one of the best-written books -- may the best -- on the practical details of programming that I've ever encountered, and the advice is gold. The section on correctly implementing equals() and hashCode() alone is almost worth the price of the book.
The reviewer complains about some of the thinner or more "obvious" items, but I disagree. Heaven only knows how many times I've wished that really good and experienced programmers follow what seems the obvious maxim: "Minimise the accessibility of classes and members."
It's true that "Know and use the libraries" seems rather obvious and vague advice, but Bloch's exposition drives home the fact that you may not follow this advice as well as you think. As always, his examples are excellent: he shows how an innocuous-seeming abuse of java.util.Random creates serious problems, and how proper use of the libraries fixes the problem. How often do you write a loop to print the contents of an array? I never realized until Bloch pointed it out that System.out.println(Arrays.asList(array)) accomplishes the same thing much more simply.
If you're a Java programmer, get this book. If you're a technical author, aspire to it.
You could go with Delphi. Anecdotal evidence suggests that many VB programmers are switching to Delphi rather than to VB.Net.
Visually, there are lots of similarities with VB, but with more power. You can go under the hood and get as low-level as you want, short of device drivers (where at least a small part must be written in C/C++).
As a bonus, data-aware controls actually work! (even MS recommends not using them in production VB code.)
There is a version (C++ Builder) that uses C++ instead of Pascal as the basic language, and another package, Kylix, that can compile Delphi/C++B source code to run on Linux.
Borland also hosts a fantastic developer community (especially newsgroups), and most components, even commercial ones, have source available. Look at Torry's for thousands of components/tools/apps.
Many important Java techniques and idioms are described so well in this book that I have been known to insert comments to the effect of:
(or some such) into my code. Most of the author's items should be as engrained in the mind of a Java developer as terms like 'singleton' and 'event listener'.
whenYouCan(keepReferencingYourObjects)->LikeThi
Actually, it should be:
whenYouCan(keepReferencingYourObjects).LikeThis
remember, no pointers... *wink, wink*
Anyways, I have yet to see anything that bad (I know you were making a point), nor have I seen anything similar that can't be fitted within 80 columns on 2 lines. You can't seriously tell me you have never seen a C/C++ line that long. You can always write horrible code no matter the language, blaming it on the language itself is just an excuse.
What are your reasons for preferring C++ (or even C#) over Java? Speed, standards-compliance, readability, lower memory usage, saner language constructs, not controlled by Sun?
Speed - used to be, IBM is doing some amazing things with their JIT compilers. I think someone else mentioned they were getting 90% of native code. So this is no longer an issue for me. I've even writing some fairly advanced 3D apps using GL4Java.
Standards-compliance - well... not sure what to say here. There's not ASCI Java if that's what you mean. Never been much of an issue for me.
Readability - as I have been arguing above, I prefer Java's... just me I guess?
Lower Memory Usage - For sure! Java's memory footprint is horrible. Price you pay for a virtual machine. I do hate this.
Saner Language Constructs - see Readability.
Not Controlled By Sun - someone has to control it, I'd say they are doing a decent job of maintaining the API. They also seem to do a fine job of listening to the needs of the users. I think sun does a fine job with the API itself, they need to improve their application of it (Sun's JVM pretty bad, etc).
My main reasons for preferring C++...
- lower level, like the control I think.
- Sun's Swing and AWT API's suck IMHO.
- Java is very large API, I get a bit overwhealmed at times.
----- "Blame the guy who doesn't speak English." -- Homer J. Simpson
Best of all, it's not 3 feet think like Effective Java Unleashed or The Effective Java Bible would be. You get lots of info with minimal fluff.
Washington, DC: It's like Hollywood for ugly people.
When this came out in 2001, James Gosling showed a copy of it at his keynote at JavaOne. They sold out every copy they had at the show, and the Effective Java talk later that day/week, was so packed you couldn't even get it. Great book.
I rarely find a tech book that offers more than a few examples I ear-mark. This book however has me re-reading it from time to time. The lessons picked up take time to sink in, and IMO no one can truly pick up all of the lessons on one read through.
I've been required to use Java non-stop from late 1995 until quite recently for school, internships, and then for my career. I've used every version of Java, and every API and just about every class available in the SDK. I've written applets, mathematical programs, games, medical database apps for the department of defense, class projects, enterprise-level call center applications, and just about anything else you could possibly conceive.
I've found in my experience that Java is good when it's highly specialized and kept very small and simple (yes, Java is good for APPLETS!). For enterprise applications, it _sucks_.
It's not that the language itself is bad (although it certainly has some gaping holes). It has more to do with the poor (buggy) implementation of the APIs and the real-time interpretation. Java isn't nearly as portable as they would have you believe (writing a 100-line applet and then running it on two different web browsers will tell you that.) Additionally, in my opinion, Java would have been much more useful if had been designed as a compiled (not interpreted) language.
In my current job, I use a lot more C++. I like it. It does what I tell it to do, and I don't have to second-guess the tools every time there's a problem.
...just my 2 gil.
Decent review of an excellent book.
I read books like other people eat hot dinners, and when I recommend Java books in work I only recommend this one. (I tend to find that a surprisingly number of coders only read one or two tech books a year anyway). "Effective java" is very well written; it's nice and short without sacrificing any exposition of the hairer parts of the language.
And as another poster has said, at work it's often sufficient to say in a review, "HashCode as per Bloch please"
It's nice to see a book review that actually reviews the book, rather than just regurgitating the table of contents.
"I don't know half of you half as well as I should like, and I like less than half of you half as well as you deserve."
Four sample chapters from the ten in the book are available in PDF format at the books website.
whenYouCan(keepReferencingYourObjects)->LikeThi
This code is a horrible violation of the
Law of Demeter. If you're doing this, formatting is not your biggest concern.
There is something about the idea of code examples being "hard-hitting" that made me laugh out loud.
Random is the New Order.
Ok, maybe you should view what I posted, and re-read the links.
IBM makes claims to Java at 90% speed of C++ in their numerical benchmarks. JavaGrande includes a number of well-respected organizations doing intensive computation, including GRID work. The tests quoted show a wide variety of performance, and you picked on file I/O; yes, one of the worst aspects in those tests. However, note that these are OLD JVM tests, not the significantly improved I/O found in JDK 1.4. (I don't have stats handy but have seen and experienced the claims of improved performance).
Java as an interpreted, cross-platform language will always be at a disadvantage to C++ in terms of raw speed. The again, many equate C++ as "Object Assembly" in the OOP world. That has it's own disadvantages.
Everything depends on how the language gets used. I have written many distributed C++ infrastructures and applications, and find Java a much welcome alternative. In many distributed scenarios it has proven faster, to the surprise of many seasoned collegues. I couldn't even imagine the jirations required to do an equivalent of JINI in C++.
So, why is it that most financial institutions have dropped C++ in favor of Java for server applications? It must suck something fierce, eh?
It's awfully funny that your example, which was supposed to illustrate something bad about Java, is actually C++, and not legal Java. Even more ironic, the Java equivalent would be several characters shorter.
...that Effective Java talks about by using a static code analyzer. Like this one:
http://pmd.sf.net/
PMD will find places where you've used concrete collections rather than interfaces, left unused code lying around, etc., etc.
Tom
The Army reading list
I've found in my experience that Java is good when it's highly specialized and kept very small and simple (yes, Java is good for APPLETS!). For enterprise applications, it _sucks_.
Interesting observation...
Why don't you give us some specific examples to back up that sweeping statement?
I have always worked on the principle of one new thing per project wherever possible. New languages are a no-no, so when I speced out projects, we stuck with languages where there was a good level of in-house knowledge - and delivered on time. Java is mainstream now so it remains a good choice even though there are OO languages that may be better. It is well supported and comes with a good collection of objects.
See my journal, I write things there
you seem to be under the illusion that java exists only for web pages. you are wrong. Most java is not contained in web pages.
-------------------------
A person of moderate zeal
Which APIs? Which bugs? Nothing is bug free. Also, your comment about "real time interpretation" is off base, see below.
Java isn't nearly as portable as they would have you believe (writing a 100-line applet and then running it on two different web browsers will tell you that.)
Applets apply to Java portability how again? Are you under the impression that some significant amount of Java development today relates to applets? Answer: not really. Further, if you use a decent JRE in both browsers you'll find you have no applet portability problems either.
Additionally, in my opinion, Java would have been much more useful if had been designed as a compiled (not interpreted) language.
Now you are exhibiting true ignorance for the world to see. There are many traditional, ahead of time, Java compilers. gcj, TowerJ and Jet come to mind. Look back at the recent article on x86 Linux numerics. Check out the linked article from that post - note gcj is only 9% slower than g++. Supposedly gcj 3.3 and 3.4 both improve gcj speed substantially over the 3.2 compiler used in that article...one guesses the more mature g++ will see less speedup.
In short, your reasons for liking C++ over Java don't hold water except for verbosity. ;-)
(BTW, I'll give you a strong reason for disliking C++ - you can't turn on bounds checking in STL arrays using operator[] without hacking STL. Ugly.)
Galileo: "The Earth revolves around the Sun!"
Score: -1 100% Flamebait
I know two Java books that are definitely worth their money:
- Effective Java
and
- Java Platform Performance by Steve Wilson and Jeff Kesselman
Of the second book there is a HTML version available at this link
Signature deleted by lameness filter.
Can you name one commercial implementation in Squeak?
Good point. However how many commericial applications are written in Java? I am not talking about custom client/server apps or installer programs but popular shrink wrap applications that are written in Java? Just curious as I never seem to encounter any and often wonder why not - given the Java advantage of cross-plateform capability.
If you're interested, you can get a free subscription to the print edition of Software Development Magazine. It's one of the few high quality freebees (and no, I am not affiliated with them). Also, as Scott Myers got mentioned here a few times: He writes for SD Magazine once in a while.
Under capitalism man exploits man. Under communism it's the other way around.
This is the best java book I have read. I swear I already knew 80% of what is in the book but I had forgotten half.
But the most useful thing about the book is that you can quote it to people. It has been a useful tool for applying to the Open Source mailing list I have to participate in.
And if you are writing an API in Java you need this book shipped to you overnight delivery. You can thank me later.
Read Epic the first RPG novel.
I'm not a big fan of Java, but I was impressed by everything that has been said here about how much Java has matured, so I figured I'd put it to the test.
I dug up some old benchmarks (the BYTEmarks, which includes a jBYTEmark, normalized to that same P90) that I can use to fairly compare Java and C performance.
I've got a 1.2Ghz Duron, and the C version of the BYTEmarks seems to reflect this accurately--with scores of 26.6 Integer and 21.4 FP, with a P90 being 1.00.
I'm comparing this against two separate Java implementations--Sun's JVM for Linux, and gcj (I also tried out a program that translates Java bytecodes to C, but the resultant executable didn't perform correctly). Here's a table of results:
C Bytemark: INT: 26.6 FP: 21.4
SUN (--server) INT: 4.21 FP: 1.80
GCJ INT: 3.63 FP: 1.71
SUN (Default) INT: 2.18 FP: 2.14
Now, I'm not surprised that the C version ran so fast, but I am surprised the the Java benchmarks did so badly, considering that both benchmarks were normalized to an index of 1.0 for the same Pentium 90! Maybe I got a bad copy of the jBytemarks--it was hard to find a copy at all--but it looks pretty legit.
Do any of you Java people have some amazing tips for me? I did use all the optimization flags I could find. Or is this typical performance for Java, making a 1.2Ghz Duron run as slow as a P200 or a K6/300?
pb Reply or e-mail; don't vaguely moderate.
After doing a bit more research about JVMs, I installed IBM's JVM, which outperforms both GCJ and Sun here:
IBM INT: 5.8 FP: 6.4
These results still aren't as good as I'd hoped, but it does show that all of the JVMs aren't up to par yet, and therefore should be careful in choosing one!
pb Reply or e-mail; don't vaguely moderate.
You, on the other hand, can rest assured that no matter what job you are doing, you will always be a tool.
Mind if I borrow that?
I didn't realize that there were so many Java fan(atics) out there. I do realize it's importance to the computer industry, and especially the acedemic industry, but there is a lot of bloat to the language. Java has become a wishlist of functions. Great for learning and teaching OOP, but as it's been abstracted too far (in my opinion) it has lost a little bit of flexibility (and a lot of its speed). Personally, I don't care about overloading methods, total abstratcion, or write once debug everywhere capabilities. Garbage collection is nice though, as well as the additional security Java has to offer, but as far as it being the last word everywhere, just ask Corel.
Your suggestion to Use a good platform independent front-ending language, like java, to provide an interface to your powerful computational engine written in C or Lisp or Perl does make sense though, and you didn't have to come across as a zealot.
I'm burning Karma to reduce my heating bills...
You think that I'm crazy, you should see this guy!