David W Brown

Howdy, recently I have had the opportunity to see a very unusual Java design pattern in action (if it is indeed a design pattern).

Attempts to Google this come up short.

The pattern in question is: an Abstract class that extends a Concrete class and implements Runnable.

The concrete class implements a couple of additional Interfaces.

The code I'm referencing is in a Java web app that is current production code and is running!

My question is twofold:

Is there a name or type of so-called Java design pattern that can be attached to the description above.

If this is a know design pattern what are the overwhelming reasons to use such a pattern or what are the advantages/disadvantages to using the pattern described above.

Hello Srivinas, what tooling do you recommend to use with Hibernate in the migration of a very de-normalized legacy system? The legacy system consists of 800+ tables, views and indices. And, the migration will have to happen in real-time against the Prod. database. I have considered using Talend or the Eclipse Middlegen plugin. There are other ETL tools in cyberspace: but I am not sure how well most ETL tools work with Hibernate. Please advise, David.

Hello Matteo, I would appreciate if you would post the difference in what you thought was a problem. I am currently having a similar problem with a referenced table unable to acquire the auto-generated key. I know the key is being generated in the parent table as I set @Rollback(value=true) on the JUnit test method. And, as a result, the parent table record gets inserted with a new record primary key ID. But, then, the new key ID value is lost on the child table that needs the generated primary key value to allow the insertion of a new record into the child table. And, as a result the record insertion attempt on the child table throws the following exceptions. Any ideas are considered helpful. Regards, David.

org.springframework.dao.DataIntegrityViolationException: SqlMapClient operation; SQL [];


com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException

--- The error occurred in com/st/data/master_SqlMap.xml.
--- The error occurred while applying a parameter map.
--- Check the master.insert-InlineParameterMap

Cannot add or update a child row: a foreign key constraint fails (`elblanco`.`master`, CONSTRAINT `fk_Master` FOREIGN KEY (`Id`) REFERENCES `master` (`Id`) ON UPDATE CASCADE); nested exception is com.ibatis.common.jdbc.exception.NestedSQLException

Hello JavaRanchers, actually, I work on a working ranch (no kidding). OK here is a good Rant-and-Raver: I am running a testcase against a simple JDBC oriented class I created in a Java web app. The JDBC class' constructor attempts to use: org.apache.wicket.markup.html.PackageResource to access a Java Properties file. But before actual test completes it bails on the following exception. The target file (dbconn.properties) is copied to the same place under the Target directory. Is that thundering hooves of thought I hear?

********************************
ERROR - org.apache.wicket.markup.html.PackageResource$PackageResourceBlockedException: package resource com/mycompany/jdbc/dbconn.properties may not be accessed
Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.031 sec <<< FAILURE!

Hello Mike, I don't remember exactly (I think I just step debugged) but it was something like: one was a Long and the other was a String. Thanks! David.

Hello Java Gurus and mortals, I have never seen this with all the junit testing I have done these past years. If anyone has an explanation, rant or rave please advise. Please find included below the amazing junit exception. This is testing the return of a primary key id. Thanks! David.


junit.framework.AssertionFailedError: expected:<2883> but was:<2883>
at junit.framework.Assert.fail(Assert.java:47)
at junit.framework.Assert.failNotEquals(Assert.java:277)
at junit.framework.Assert.assertEquals(Assert.java:64)
at junit.framework.Assert.assertEquals(Assert.java:71)

Hello, I know this is somewhat dated material but I was in the throes of a project and related solutions at my job when I have mavenized the TextDiff solution. If anyone is interested I can put this somewhere on the net. I have a blog that I have up-and-running but I have held off on putting any content on the blog. If there is any interest I can put the mavenized TextDiff files there such that folks can download TextDiff from the blog. Please advise, David.

Hello Joe, thanks for the reply. I tried: -Dtempdir=TEMP as follows:

startWeblogic.cmd -Dtempdir=TEMP

This is the exception I get:

JAVA Memory arguments: -Xms256m -Xmx512m -XX:CompileThreshold=8000 -XX ermSize=48m -XX:MaxPermSize=128m
.
WLS Start Mode=Development
.
CLASSPATH=C:\bea\domains\fcservicing92-online\lib\mbeantypes\authprovider.jar;c:\bea;;C:\bea\patch_weblogic923\profiles\default\sys_manifest_classpath
\weblogic_patch.jar;C:\java\lib\tools.jar;C:\bea\WEBLOG~1\server\lib\weblogic_sp.jar;C:\bea\WEBLOG~1\server\lib\weblogic.jar;C:\bea\WEBLOG~1\server\li
b\webservices.jar;;C:\bea\WEBLOG~1\common\eval\pointbase\lib\pbclient51.jar;C:\bea\WEBLOG~1\server\lib\xqrl.jar;;
.
PATH=C:\bea\patch_weblogic923\profiles\default\native;C:\bea\WEBLOG~1\server\native\win\32;C:\bea\WEBLOG~1\server\bin;C:\java\jre\bin;C:\java\bin;C:\P
rogram Files\Windows Resource Kits\Tools\;C:\Program Files\Subversion\bin;C:\java\bin;C:\Documents and Settings\dwbrown\My Documents\dev\java\apache-a
nt-1.7.0\bin;C:\Program Files\CVSNT\;C:\Documents and Settings\dwbrown\My Documents\dev\java\apache-maven-2.0.9\bin;C:\Program Files\SSH Communication
s Security\SSH Secure Shell;C:\Documents and Settings\dwbrown\My Documents\dev\java\apache-ant-1.7.0\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\Sys
tem32\Wbem;C:\Program Files\Common Files\OTG;C:\Program Files\Support Tools\;C:\WINDOWS\system32\nls;C:\WINDOWS\system32\nls\ENGLISH;C:\Program Files\
Xythos\Xythos Enterprise Document Manager Evaluation\pgsql\bin;C:\Program Files\Xythos\Xythos Enterprise Document Manager Evaluation\pgsql\lib;C:\Prog
ram Files\QuickTime\QTSystem\;C:\java\bin;C:\Documents and Settings\dwbrown\My Documents\dev\java\apache-ant-1.7.0\bin;C:\Program Files\CVSNT\;C:\Docu
ments and Settings\dwbrown\My Documents\dev\java\apache-maven-2.0.9\bin;C:\Program Files\SSH Communications Security\SSH Secure Shell;C:\Documents and
Settings\dwbrown\My Documents\dev\java\apache-ant-1.7.0\bin;Y:.;Z:.;;C:\bea\WEBLOG~1\server\native\win\32\oci920_8
.
***************************************************
* To start WebLogic Server, use a username and *
* password assigned to an admin-level user. For *
* server administration, use the WebLogic Server *
* console at http:\\hostname ort\console *
***************************************************
starting weblogic with Java version:
java version "1.5.0_12"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_12-b04)
Java HotSpot(TM) Client VM (build 1.5.0_12-b04, mixed mode, sharing)
Starting WLS with line:
C:\java\bin\java -client -Xms256m -Xmx512m -XX:CompileThreshold=8000 -XX ermSize=48m -XX:MaxPermSize=128m -Xverify:none -da -Dplatform.home=C:\b
ea\WEBLOG~1 -Dwls.home=C:\bea\WEBLOG~1\server -Dwli.home=C:\bea\WEBLOG~1\integration -Dweblogic.management.discover=true -Dwlw.iterativeDev= -Dwlw.t
estConsole= -Dwlw.logErrorsToConsole= -Dweblogic.ext.dirs=C:\bea\patch_weblogic923\profiles\default\sysext_manifest_classpath -Dweblogic.Name=fcservic
ing92-online-adminServer -Djava.security.policy=C:\bea\WEBLOG~1\server\lib\weblogic.policy -Dtempdir TEMP weblogic.Server
Exception in thread "main" java.lang.NoClassDefFoundError: TEMP

Hello BEA/WL gurus and users, I have the dubious task of including a command-line argument to the startWeblogic.(cmd|sh) script such that at run-time I can retrived the value of name from a servlet deployed as a .war on the same WL instance.

Please advise, David.

Originally posted by arulk pillai:
Thanks Darren. It took a good 2 years part-time to write. I collected the information over 3 years.

Hello Arulk, in all-likelihood I will be getting this book as the phone and face-to-face interviews have become increasingly more difficult than in years past. I have noticed a trend with interviews, say typically, a 2 or 3 tech interview gauntlet: each tech has about 5 to 10 questions for a total of 10 to 30 questions for the opening gambit. The more expertly I answer questions the more the level of difficulty of the questions increases until the questions are from the more infrequently used and obscure parts of the Java code including frameworks and toolkits derived from core Java. One wrong answer during the interview and it is game over. Background and experience seem to have no weight in getting a Java job. I would expect that background and experience is needed to write a book about Java interveiw questions. Unfortunately, I for one and many other Java Programmers cannot write books about Java for a living.

Originally posted by Dawn Dizney:
We have an exceptional opportunity for an individual that has solid Java and SQL development skills as well as Testing experience! We have a client in Addison, TX with an immediate contract need. The position will entail analyzing requirements, technical specifications and legacy systems to develop quality assurance test harnesses.

Qualified individual will have solid software development skills using Java, Oracle, SQL Server, VB and MS Access. Testing experience with QTP, LoadRunner and/or WinRunner Automated tools is highly desired! This position will entail development and testing of web and client/server applications for tracking data. Individual also needs to have an understanding of WebMethods and 360 Commerce core.

Don't delay! Send your resume to ddizney@capstoneinc.com today!

PLEASE NO THIRD PARTIES/NO VISA SPONSORSHIP

E/O/E

[ February 14, 2008: Message edited by: Dawn Dizney ]

Hello Dawn, I have sent you and email with resume and cover attached. I have just rolled off a gig with a #2 or #3 size O&G operator. They have a large data center in San Ramon, CA. I worked from Houston. There current JBoss/Tomcat installation for 3 web apps and 1 WS needed to scale to 25k users. After interviewing the entire San Ramon I.T. staff and management I came to the conclusion to test their systesm against 25 concurrent users. At this number of users the model of their network topology I built in their so-called development environment began to drop transactions after about 25 concurrent users. I delivered a 20 page bound report stating facts as stated in the previous sentence. Additionally, I backed up my statements with baseline metrices derived from the JMeter test tool. I also, devised a plan to expand their server configuration with multiple Tomcat and JBoss instances deployed using SmartFrog (HP labs). Using the virutalized environment offered by Tomcat 6.x and JBoss 4.2.x I was able to scale up their systems with gap analysis metrics using the JMeter tools and I established real-time monitoring using JMeter and MC4J. Please advise, David.