Sam Egbert

Anybody looking to learn or discuss Android RESTful Design Patterns can certainly benefit with a visit to this blog:

Android Restful Design Pattern with ContentProvider & SyncAdapter

Specifically, we will be discussing Virgil Dobjanschi's REST Option "C" as presented in his Google I/O video.

What I am doing is using commit-option A for CMP caching. Would anybody know if there is a way to programmatically invalidate the cache so that the entity beans will be forced to retrieve new copy of data from the database?

Thanks in advance for any help in this matter.

Thanks for your input. It provided me with much needed advice that I could not find elsewhere on the web or books that I have used for research.

For now I will go with storing an encrypted password which is stored in a file on the server. I will try to protect that file as much as possible. The data is not super-sensitive so this should suffice for now. As the application expands and features are added we will probably need more security. That is when I will consider introducing the "external factor" you mentioned.

Hi,

I have been doing some research on how to encrypt/decrypt data for a J2EE application running in a JBoss server. It seems that there is a mountain of information dealing with encrypting data to
be sent over the wire and decrypted by other applications. What I am really interested in is encrypting sensitive data to be stored by my application.

My passwords are stored using the MD5 one-way hashing algorithm. This is working fine.

I am using the Bouncy Castle Provider to store encrypted data on a database and decrypt this data when it is retrieved. I am using Password Base Encryption (PBEWithSHAAnd3KeyTripleDES) to accomplish this.

This all works great, but my problem is that I have to store a password somewhere that is accessible by my application but cannot be view by hackers. The only solution that I have seen so far is to store an encrypted password in a file on my server. When I need the password I will have code to decrypt the password.

With this solution, if a hacker gets access to the database data, the password decryption code and the file with the encrypted password he will be able to break into my sensitive data.

Does anybody have experience with storing a private password in a JBoss application and retrieving it programmatically with java?

Thanks for any help in this area.

I noticed that this error occured every time any method was call on a specific class. After some further investigation I realized that this class was deployed in both .war and .jar files. I removed it from the .war file and the error no longer occurs.

I noticed that this error occured every time any method was call on a specific class. After some further investigation I realized that this class was deployed in both .war and .jar files. I removed it from the .war file and the error no longer occurs.

Thanks for your response.

I am actually running my application within the latest version of JBoss Application Server. I am pretty sure this version of JBoss was compiled using JVM 1.4. I will do some more investigating to make sure.

I get the following error while running a Java application on Windows XP. Has anybody encountered this same problem?

Thanks in advance for your help.

#
# HotSpot Virtual Machine Error, Internal Error
# Please report this error at
# http://java.sun.com/cgi-bin/bugreport.cgi
#
# Java VM: Java HotSpot(TM) Client VM (1.4.2-b28 mixed mode)
#
# Error ID: 43113F32554E54494D45110E4350500308
#
# Problematic Thread: prio=5 tid=0x02e40048 nid=0xad0 runnable
#

Heap at VM Abort:
Heap
def new generation total 9216K, used 1208K [0x10010000, 0x10a00000, 0x1277000
0)
eden space 8256K, 14% used [0x10010000, 0x1013e150, 0x10820000)
from space 960K, 0% used [0x10910000, 0x10910000, 0x10a00000)
to space 960K, 0% used [0x10820000, 0x10820000, 0x10910000)
tenured generation total 121024K, used 37365K [0x12770000, 0x19da0000, 0x3001
0000)
the space 121024K, 30% used [0x12770000, 0x14bed6d0, 0x14bed800, 0x19da0000)

compacting perm gen total 22784K, used 22563K [0x30010000, 0x31650000, 0x34010
000)
the space 22784K, 99% used [0x30010000, 0x31618e58, 0x31619000, 0x31650000)
Press any key to continue . . .

I get the following error while running my JBoss application. Has anybody encountered this same problem?

Thanks in advance for your help.

#
# HotSpot Virtual Machine Error, Internal Error
# Please report this error at
# http://java.sun.com/cgi-bin/bugreport.cgi
#
# Java VM: Java HotSpot(TM) Client VM (1.4.2-b28 mixed mode)
#
# Error ID: 43113F32554E54494D45110E4350500308
#
# Problematic Thread: prio=5 tid=0x02e40048 nid=0xad0 runnable
#

Heap at VM Abort:
Heap
def new generation total 9216K, used 1208K [0x10010000, 0x10a00000, 0x1277000
0)
eden space 8256K, 14% used [0x10010000, 0x1013e150, 0x10820000)
from space 960K, 0% used [0x10910000, 0x10910000, 0x10a00000)
to space 960K, 0% used [0x10820000, 0x10820000, 0x10910000)
tenured generation total 121024K, used 37365K [0x12770000, 0x19da0000, 0x3001
0000)
the space 121024K, 30% used [0x12770000, 0x14bed6d0, 0x14bed800, 0x19da0000)

compacting perm gen total 22784K, used 22563K [0x30010000, 0x31650000, 0x34010
000)
the space 22784K, 99% used [0x30010000, 0x31618e58, 0x31619000, 0x31650000)
Press any key to continue . . .

The sample app had all the following jar files in the war under WEB-INF/lib.

commons-beanutils.jar
commons-collections.jar
commons-digester.jar
commons-fileupload.jar
commons-logging.jar
commons-validator.jar
jakarta-oro.jar
struts.jar

There were duplicates in my app server directory (C:\Sun\AppServer\lib). I removed duplicates. Then I moved the jar files to and from the sample app and the app server trying different combinations. The only configuration that works is when I remove all of these jar files from WEB-INF/lib in the war and put them in C:\Sun\AppServer\lib.

I don't know if this is the best configuration, but it is working for now.

Thanks,
Sam

I am making some progress by cleaning up some duplicate jars I have floating around my classpath. I will post my findings after a little more experimentation.
[ April 19, 2005: Message edited by: Sam Egbert ]

I am trying to run the MailReader sample application. I have struts.jar and all the other common jars in the WEB-INF/lib directory.

I get the following exception when I try to run MailReader:

[#|2005-04-18T21:15:52.531-0500|SEVERE|sun-appserver-pe8.1|org.apache.commons.digester.Digester|_ThreadID=10;|Begin event threw exception
java.lang.ClassNotFoundException: org.apache.struts.util.LabelValueBean
at java.net.URLClassLoader$1.run(URLClassLoader.java:199)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at org.apache.commons.digester.ObjectCreateRule.begin(ObjectCreateRule.java:252)
at org.apache.commons.digester.Rule.begin(Rule.java:200)
at org.apache.commons.digester.Digester.startElement(Digester.java:1273)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:485)...


Any help would be greatly appreciated.