Spotted @ #015 Group Therapy Radio with Above & Beyond

Problem

When I execute DDL statements to my MySQL database on my Mac installation, every table is converted to lowercase letters - even if the name is in uppercase letters in my script. This leads to errors in ALTER TABLE operations to add foreign keys (because of case sensitive).

Solution

According to this page:

How table and database names are stored on disk and used in MySQL is affected by the lower_case_table_names system variable, which you can set when starting mysqld. lower_case_table_names can take the values shown in the following table. This variable does not affect case sensitivity of trigger identifiers. On Unix, the default value of lower_case_table_names is 0. On Windows the default value is 1. On Mac OS X, the default value is 2.

I updated my my.cnf file:

$ sudo nano /private/etc/my.cnf

... by adding the following line:

lower_case_table_names=0

Problem

Fonts like Tahoma, Verdana, ... are missing on a standard Ubuntu installation. I was looking to install the Microsoft TrueCrypt fonts so I could open Word documents (created in Microsoft Office) correctly in OpenOffice. Also, I had the issue some of my webpages were not looking ok in Firefox (Linux) - fonts were missing, so pages could look totally different.

Solution

• Install package msttcorefonts

$ sudo aptitude install msttcorefonts

• To be able to reload the fonts, without rebooting the machine, execute the command:

$ sudo fc-cache -fv

I came across some issues with processing secured PDF's. These PDF files were encrypted. After reading the following documentation: http://publib.boulder.ibm.com/infocenter/zos/v1r11/index.jsp?topic=/com…, I tried securing one of my own PDF's.

Goal

Encrypting the PDF so text cannot be copy/pasted and the PDF could not be printed

Requirements

• iText
• BouncyCastle jars

Libraries used

• iText: 5.3.5
• BouncyCastle: bcprov-jdk14-1.47.jar and bcprov-ext-jdk14-1.47.jar

Code

import java.io.FileOutputStream;
 
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfStamper;
import com.itextpdf.text.pdf.PdfWriter;
 
public class EncryptPDF {
 
	private static final String INPUT_FILENAME = "/tmp/test.pdf";
	private static final String OUTPUT_FILENAME = "/tmp/test_encrypted.pdf";
	private static final String USER_PASSWORD = "";
	private static final String OWNER_PASSWORD = "foobar";
 
	public static void main(String[] args) {
		PdfReader reader = null;
		FileOutputStream out = null;
		PdfStamper stamper = null;
 
		try {
			// Define input
			reader = new PdfReader(INPUT_FILENAME);
 
			// Define output
			out = new FileOutputStream(OUTPUT_FILENAME);
 
			// Encrypt document
			stamper = new PdfStamper(reader, out);
			stamper.setEncryption(USER_PASSWORD.getBytes(), OWNER_PASSWORD.getBytes(), 0, PdfWriter.STANDARD_ENCRYPTION_128);
		} catch (Exception ex) {
			ex.printStackTrace();
		} finally {
			if (stamper != null) {
				try {
					stamper.close();
				} catch (Exception ex) {
					ex.printStackTrace();
				}
			}
			if (reader != null) {
				try {
					reader.close();
				} catch (Exception ex) {
					ex.printStackTrace();
				}
			}
			if (out != null) {
				try {
					out.close();
				} catch (Exception ex) {
					ex.printStackTrace();
				}
			}
		}
	}
}

Extra

You can also play with the permissions by providing PdfWriter perms instead of the value "0".

stamper.setEncryption(USER_PASSWORD.getBytes(), OWNER_PASSWORD.getBytes(), PdfWriter.ALLOW_ASSEMBLY | PdfWriter.ALLOW_COPY, PdfWriter.STANDARD_ENCRYPTION_128);

Check if PDF is secured

• When opening the PDF with Acrobat Reader, the title should end with: (SECURED)
• Open the properties of the PDF in Acrobat Reader ( ⌘ + D on a Mac ) and look at Document Restrictions Summary

Problem:

When you boot your Ubuntu installation, a lot of scripts are started. A lot of scripts are superfluous. But how to disable the ones you don't need?

Solution:

• Install rcconf

$ sudo aptitude install rcconf

• Disable the service by toggling the service using the "space bar".

$ sudo rcconf

• Choose Start
• Typ and launch Performance Monitor (perfmon.msc)
• Choose Monitoring Tools > Performance Monitor
• Choose Add ...
• Locate Pages Input/Sec in the Memory section
• The higher the number, the higher your Windows machine is swapping

If you want to format the following XML document:

<?xml version="1.0" encoding="UTF-8"?><ROOT><FOO><BAR>Hello World</BAR></FOO><BAR><FOO>World Hello</FOO></BAR></ROOT>

... you can use Vi in combination with Xmllint to do the formatting

$ vi example.xml
:%!xmllint --format -

... the result will be:

<?xml version="1.0" encoding="UTF-8"?>
<ROOT>
  <FOO>
    <BAR>Hello World</BAR>
  </FOO>
  <BAR>
    <FOO>World Hello</FOO>
  </BAR>
</ROOT>

When building Richfaces 3.3.x from source, you might run into the following error:

richfaces\framework\test\src\main\java\org\ajax4jsf\tests\EnumSupportExpressionFactoryWrapper.java:[32,7] org.ajax4jsf.tests.EnumSupportExpressionFactoryWrapper is not abstract and does not override abstract method coerceToType(java.lang.Object,java.lang.Class) in javax.el.ExpressionFactory

The solution to solve this error:


The problem is that there are different versions of the "el-api-1.0.jar" on the Internet.

You don't have to clear the whole local repository or circumvent your Maven proxy. It is just enough to delete all files in %HOME_DIR%\.m2\repository\javax\el\el-api\1.0\ and download http://download.java.net/maven/1/javax.el/jars/el-api-1.0.jar into that folder.


There are many comparison lists to find on the web, but this is one I've created after I tested GIT. I have a lot of experience with Subversion, but I was wondering what the power/advantages of GIT are.

What is GIT?

GIT is a free distributed revision control, or software source code management project with an emphasis on being fast. GIT was initially created by Linus Torvalds for Linux kernel development.

Every GIT working directory is a full-fledged repository with complete history and full revision tracking capabilities, not dependent on network access or a central server.

Several high-profile software projects now use GIT for revision control, most notably the Linux kernel, Perl, Samba, X.org Server, Qt (toolkit), One Laptop per Child (OLPC) core development[5], Ruby on Rails web framework, VLC, Merb, Wine, SWI Prolog, DragonFly BSD and the Android mobile platform.

Pro's

• distributed: you are no longer dependent on 1 server. You can also retrieve data from your "neighbours" which have also checked out some code of a server. The retrieval of this data is called a pull operation; the sending of data to your neighbours (also called remotes), is called a push operation
• .git folder: in contrast of Subversion in which each folder has a .svn directory, GIT will only create 1 .git folder. In this folder, each file/folder which is changed/added/deleted/renamed/ ... gets tracked. This .git folder is basicly an index in which files/folders can be quickly retrieved
• DAG all data gets stored as a DAG (Directed Cyclic Graph). SVN uses a tree architecture. The use of a DAG gives GIT the possibility to create branches from different "trees". Different knots can point to different branches
• GUI tools: if you don't like the commandline to use GIT, you can use of the many GUI tools like TortoiseGIT to keep track of changes in your directory in a graphical way
• Merging: the way GIT thinks about merging is more flexible than SVN. For example: you can merge little parts of files to another branch, and leave the other changes in the file in your working copy. This is called: committing a hunk
• changes: the changes to a tree can easily be e-mailed to other persons
• history: asking for the history of file/folder in GIT is so much faster than SVN as you don't need a central server to ask for history. All history is stored in an index file
• goal: GIT is very useful for open source projects: contributors can simply make patches, branch, merge branches of various contributors, all independent on the master server

Cons

• distributed: it seems to be an advantage to move from a centralized to a distributed system, yet, it seems weird that you can retrieve data from the neighbours as well (and not only from a central repository). For me, this is something really strange. Imagine each developer has its own GIT local repository. If you want to update your local repository, you have to fetch the updates from all of the developers? Or do you still need a central repository? But then I need to commit AND and I need to push the changes to the central repository. That's 1 extra operation compared with SVN
• high learning curve: a wide variety of commands can make this tool very complex. If you want to introduce GIT in your team, I really think you should have at least one developer which has advanced knowledge/experience of GIT. Or each of the developers needs to be for 100% committed to use this new version control system. Otherwise, people will be quickly annoyed.

This evening, I played a little bit with Oracle JDeveloper 11g (http://www.oracle.com/technetwork/developer-tools/jdev/overview/index.h…). I'm using Eclipse since 2007 as IDE and I'm very happy with it, but I was wondering how JDeveloper works.

I wanted to import some existing Java projects into my JDeveloper workspace. I'm used to run the $ mvn eclipse:eclipse command to create a .project and .classpath file, but I noticed there's no $ mvn jdeveloper:jdeveloper command. However, after Googling, I found that Trinidad developed a custom plugin which does exactly the same.

To let it work, add the following tag in the pom.xml file:

<build>
    <plugins>
      <plugin>
        <groupId>org.apache.myfaces.trinidadbuild</groupId>
        <artifactId>maven-jdev-plugin</artifactId>
      </plugin>
    </plugins>
</build>

Then, run the following command:

$ mvn jdev:jdev

This command will create a JDeveloper .jpr project file which you can easily import in JDeveloper.