Wed Sep 02 16:28:22 GMT 2009 From /weblog/design

composition over inheritance

Good example of composition over inheritance - http://www.javablogging.com/comparable-vs-comparator/

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Wed Jun 25 01:59:02 GMT 2008 From /weblog/design/exception

problem of using exception for control flow

Other than harder to read, this approach is easier to have side effect, consider the following case:

    // Code which fail
    public String service() { 
        try {
	// a lot of other code....	
            return getRecord();
        } catch (SQLException re) {
            return "defaultRecord";
        }
    }

    private String getRecord() throws SQLException {
        PreparedStatement ps = getConnection().prepareStatement("select something from sometable");
        try {
            final ResultSet rs = ps.executeQuery();
            try {
                if (rs.next())
                    return rs.getString(1);
                else
                    throw new NotFoundException();
            } finally {
                rs.close();
            }
        } finally {
            ps.close();
        }

        // definition of NotFoundException, analog to IOException and FileNotFoundException
        public final class NotFoundException extends SQLException {....}

The idea is, for any database problem, just return default value. However, if someone change the interface of NotFoundException to

public final class NotFoundException extends RuntimeException {....}

Then it break service() silencely :-/ Some to it is better to have

    // Code which fail
    public String service() {
        try {
        // a lot of other code....
            return getRecord() == null ? "defaultRecord" : getRecord();
        } catch (SQLException re) {
	// proper exception handling
        }
    }

    private String getRecord() throws SQLException {
        PreparedStatement ps = getConnection().prepareStatement("select something from sometable");
        try {
            final ResultSet rs = ps.executeQuery();
            try {
                if (rs.next())
                    return rs.getString(1);
                else
                    return null;
            } finally {
                rs.close();
            }
        } finally {
            ps.close();
        }

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Tue May 06 06:25:04 GMT 2008 From /weblog/design/interview

Donald Knuth

Donald Knuth on Multi-Core, Unit Testing, Literate Programming, and XP:

I also must confess to a strong bias against the fashion for reusable code. To me, "re-editable code" is much, much better than an untouchable black box or toolkit. I could go on and on about this. If you’re totally convinced that reusable code is wonderful, I probably won’t be able to sway you anyway, but you’ll never convince me that reusable code isn’t mostly a menace...

http://www.artima.com/forums/flat.jsp?forum=276&thread=229705

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Mon Apr 28 17:46:55 GMT 2008 From /weblog/design/interview

Bjarne Stroustrup

Nice message cover DSL, IDE, multiple dispatch, message passing, and more

http://msdn2.microsoft.com/en-us/magazine/cc500572.aspx

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Mon Mar 17 17:25:25 GMT 2008 From /weblog/design/examples

suggestion of search engine improvement

Nice suggestions, I think this can apply to most search function

Don’t tell me everything you know - limit to specific set of datas , like ameture / professional
Ask me the next most reasonable question
Offer me to establish my search identity

http://jooto.com[..]008/01/05/how-to-improve-search-engines/

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Mon Mar 17 17:25:24 GMT 2008 From /weblog/design/exception

Handle exception at event

To prevent no one notice there is problem

What the code is trying to do is make sure is that any exception thrown is brought to the attention of the user. I’ve been looking at a few approaches to help catch and handle these exceptions without the developer having to explicitly catch them at the UI level.
You can create your own EventQueue, and have it catch uncaught exceptions when dispatching methods

http://www.magpiebrain.com[..]2004/07/21/catching-uncaught-exceptions/

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Fri Dec 14 04:03:17 GMT 2007 From /weblog/design

sorting

Show a design of how to write a map that store data at disk and do sorting - http://mattfleming.com/node/53

User friendly sort , "100" should be sort after "10" - http://www.codinghorror.com/blog/archives/001018.html

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Wed Dec 12 10:38:08 GMT 2007 From /weblog/design

qconsf

2007 summary, include discussion about distributed, dsl, arhitecture, XP, ... and many others - http://www.infoq.com/articles/qconsf-2007-summary

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Tue Dec 11 09:50:05 GMT 2007 From /weblog/design

string

Discussion about search and replace for a lot of files - http://discuss.joelonsoftware.com/default.asp?design.4.570350

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Thu Dec 06 08:34:42 GMT 2007 From /weblog/design

report

TDD reporting system

Only introduce framework when it is needed - http://xprogramming.com/xpmag/dbcCallingTheShot.htm
Process of improving - http://xprogramming.com/xpmag/dbcLjuticMonoGun.htm
Introduce reflection - http://xprogramming.com/xpmag/dbcLjuticRefactoring.htm

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Sat Dec 01 08:18:17 GMT 2007 From /weblog/design

convention over configuration

Make it is easier for user to working with your API / framework - http://www.google.com[..]uration&sourceid=opera&ie=utf-8&oe=utf-8

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Wed Nov 21 06:20:13 GMT 2007 From /weblog/design

boolean

Try not to have boolean at the interface - http://www.jroller.com[..]Ruiz/entry/boolean_arguments_can_be_evil

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Tue Nov 13 08:06:21 GMT 2007 From /weblog/design

non-blocking

A few example of writing non-blocking thread safe method, mostly using the concept of Idempotency

http://mailinator.blogspot.com[..]readerwriter-in-java-in-nonblocking.html
http://www-128.ibm.com[..]works/java/library/j-jtp04186/index.html
http://blogs.azulsystems.com/cliff/2007/03/a_nonblocking_h.html
http://lalitpant.blogspot.com/2007/05/efficient-concurrency.html
http://en.wikipedia.org/wiki/Lock-free_and_wait-free_algorithms

Not exactly related, some project about non-blocking IO
http://twistedmatrix.com/trac/
https://grizzly.dev.java.net/

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Sun Nov 11 15:32:58 GMT 2007 From /weblog/design/interview

Martin Fowler interview

The discussion of "Flexibility and Complexity" and "Flexible versus Reusable" answer my long question of how to have flexibility code with simple design.

http://www.artima.com/intv/flexplexP.html

Another interview - http://www.infoq.com/presentations/modifiability-fowler

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Sun Nov 11 15:30:06 GMT 2007 From /weblog/design

starting point

Where do you start your design? UI? flow? Data? This is a very interesting discussion about this

http://www.theserverside.com/news/thread.tss?thread_id=44883

I think most likely start with UI is better, because it probably representing domain closer

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Fri Nov 09 11:06:25 GMT 2007 From /weblog/design

reuse

some common pitfall of code reuse - http://tomasvarsavsky.com/2007/07/26/wary-of-code-reuse/ http://www.infoq.com/news/2007/07/worthless-code

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Wed Sep 12 18:01:25 GMT 2007 From /weblog/design

Transactional memory

Someone say the basic idea behind transactional memory is that memory is shared by all the threads in a read-only manner. Threads modify data by "committing" objects to shared memory. If a thread commits on top of a dirty object then it has to "rollback" and retry.

http://research.sun.com[..]007/2007-08-13_transactional_memory.html
http://www.hpcwire.com/hpc/1196095.html

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Fri Aug 24 05:33:09 GMT 2007 From /weblog/design

typing

Discussion of dynamic and static typing: http://www-128.ibm.com[..]orks/java/library/j-cb05236.html?ca=drs-

There are always arguement of having compilataion checking is good (safe) or bad (tedious), here is an example showing compilation checking is good - http://udidahan.weblogs.us/archives/036626.html

Another discussion - http://discuss.joelonsoftware.com/default.asp?joel.3.401797 http://blog.objectmentor.com[..]gly-typed-languages-considered-dangerous

Reference information of types - http://cdsmith.twu.net/types.html http://www.artima.com/weblogs/viewpost.jsp?thread=209353

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Tue Aug 21 16:57:24 GMT 2007 From /weblog/design/pattern

survey

Survey about how people feel about design pattern - http://www-etud.iro.umontreal.ca/~foutsekh/SomeResults.pdf http://tech.groups.yahoo.com/group/refactoring/message/8651

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Thu Aug 09 17:59:30 GMT 2007 From /weblog/design/interview

Erich Gamma

Erich Gamma: A pattern is always a problem-solution pair that can be applied in a particular context. Although the solutions might look similar in different patterns, the problems they are solving are different. In fact from ten thousand meters most patterns solve a problem by adding a level of indirection. What is interesting is how this indirection comes about and in particular why it needs to happen.
Therefore if you just look at the solution to the problem, it isn't that enlightening and everything starts to look the same. When we wrote design patterns we often had this feeling??hey all started to look like the Strategy pattern.

http://www.artima.com/lejava/articles/patterns_practice.html

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Thu Aug 02 15:45:23 GMT 2007 From /weblog/design

binary search

Simple and fast - http://www.tbray.org/ongoing/When/200x/2003/03/22/Binary

Possible bug, fix and lesson learnt - http://searchforquality.blogspot.com[..]ot.com/2007/06/very-interesting-bug.html http://googleresearch.blogspot.com[..]xtra-extra-read-all-about-it-nearly.html

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Thu Jul 12 11:35:52 GMT 2007 From /weblog/design/IoC

spring discussion

Discuss the problem of using springs framework, it mainly complaint about the complication of spring, I will think people know what they are using, if it is too complex, just pick other

http://crazybob.org/2006/01/i-dont-get-spring.html

Another discussion complaint about spring - http://www.theserverside.com[..]_id=46041&asrc=EM_NLN_1757981&uid=703565

Some counter opinions to those complaints - http://jroller.com/page/wiradikusuma?anchor=5_reasons_why_i_won

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Thu Jul 12 08:20:21 GMT 2007 From /weblog/design/exception

anti-pattern of exception

Mostly agree, however, why do we need NoSuchMethodException? Why we don't just don't implement that method? If this is required by the interface, why we implement an interface but not complete the contact?

http://today.java.net[..]/06/exception-handling-antipatterns.html http://softarc.blogspot.com[..]06/exception-handling-anti-patterns.html

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Wed Jun 13 17:14:39 GMT 2007 From /weblog/design/exception

check or uncheck

Checked or unchecked? Not sure, seen all exception is unchecked are ok for me

To summarize Java orthodoxy: checked exceptions should be the norm. Runtime exceptions indicateprogramming errors.
I used to subscribe to this view. However, after writing and working with thousands of catch blocks, I've come to the conclusion that this appealing theory doesn't always work in practice. I'm not alone. Since developing my own ideas on the subject, I've noticed that Bruce Eckel, author of the classic book Thinking in Java, has also changed his mind. Eckel now advocates the use of runtime exceptions as the norm, and wonders whether checked exceptions should be dropped from Java as a failed experiment

http://www.mindview.net/Etc/Discussions/CheckedExceptions

Other discussion of checked or unchecked - http://www.theserverside.com/news/thread.tss?thread_id=35586 http://www.infoq.com[..]2007/05/removing-java-checked-exceptions

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Thu May 03 07:09:00 GMT 2007 From /weblog/design

configuration

An useful discussion about that balancing config and coding

http://worsethanfailure.com/Comments/Soft_Coding.aspx

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