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Edited 2021-02-08 to reflect API changes for Java 11.

There are a number of cases when you may not know exactly what class you will be instantiating and want to be able to dynamically instantiate specific classes based on a configuration file or a condition during runtime.

To do so, you will need to define a parent class, abstract class, or interface for your classes and can then use the following code as a guide.

Given the following class definitions:→ Continue reading “Dynamically Instantiating Classes in Java”

http://regexlib.com/Search.aspx?k=URL&AspxAutoDetectCookieSupport=1→ Continue reading “Regular Expression Library”

If you want to retain the file permissions of a file that you copy with ant you must use the <exec> command instead of? <copy>.

So, instead of:

<copy file=”${source.file}” tofile=”${dest.path}/${dest.file}” overwrite=”true”/>

Use:

<exec executable=”cp”>
? <arg value=”-pf”/>
? <arg value=”${source.file}”/>
? <arg value=”${dest.path}/${dest.file}”/>
</exec>→ Continue reading “Preserving File Permissions When Copying Files with Ant”

I am writing an application that copies files from a Samba share using the JCIFC Java CIFS Client Library (which, btw, is a very helpful, widely used, and well developed project).

As usual I am under the gun to get something up and running so I do not have the luxury to explore all of the details as much as I would like. My application gets a directory listing of a Samba share and then spawns a new thread for → Continue reading “java.lang.OutOfMemoryError: unable to create new native thread Exception When Using SmbFileInputStream”

Often times I will be building a Java program that will either be run from a command-line or as a system service.  In most cases, during development, I’ll be running it directly from the command-line and will want to kill it by pressing control c on the keyboard.

When I do that I want to make sure that my program cleanly exits, closing any open files, socket connections, database connects, or what have you.

To do so, you must invoke → Continue reading “Adding a ShutdownHook to a Java Program to Enable Clean Exit on CTRL-C”

Smart quotes will be displayed as <91> and <92> in vi. A number of other special characters will also be displayed in similar fashion <96>, etc. . . .

To replaced them use do the following:

1. Type:? ‘:’ 1,%s/
2. Then, since it is a special character, you can’t simply type ‘<91>’ or that string will not be matched, so:

1. Press: CTRL and V
2. Then type: [space] x [space] 91
3. [Enter]

→ Continue reading “Replacing Smart Quotes (<91> and <92>) in vi”

I am in the process of setting up some CentOS/RHEL 6 servers to run SELinux in strict mode. What follows are notes, links to online resources and things that I am discovering along the way. Once I am finished I will go back and re-write it to follow more of a how-to/guide type format. In the meantime, it might seem a bit disjointed.

Links/Resources:

• http://wiki.centos.org/HowTos/SELinux
• http://fedoraproject.org/wiki/SELinux
• http://www.centos.org/docs/5/html/Deployment_Guide-en-US/rhlcommon-chapter-0001.html
• http://www.nsa.gov/research/selinux/index.shtml

MaintLog Notes:

• Make sure that the selinux-policy-strict package (and deps) are installed:

→ Continue reading “Configuring CentOS to run SELinux in Strict Mode”

Sent to me by my friend, Wendy:

When attempting to run a yum (search/install) if you get a the “Metadata file does not match checksum” error, try the following:

# yum clean all

# yum makecache

# yum update

→ Continue reading “Fixing Metadata file does not match checksum”

Very handy random string generator:

http://www.random.org/strings/ → Continue reading “Random String Generator”

If you are having trouble getting a DHTML drop-down menu to display on top of a Flash movie try adding the following to the <object> tag that embeds the .swf file in your .html.

Add the following as a child to the <object> tag:

<param name=”wmode” value=”transparent” />

Add the following as an attribute to the <object> tag:

wmode=”transparent”

I was having trouble getting a JavaScript dropdown to render over a Flash movie under IE and after adding the aforementioned → Continue reading “Getting JavaScript CSS Dropdown Menu to Render Over a Flash Component”