Is this file the same as that file? The files may or may not be binary. We could compare the modify dates, or the sizes. But, those are not very accurate to know if a file has really changed.

Introducing MD5 Checksum. We can feed the files into Digest::MD5 in binary mode.

This is a great way to do Incremental Backups.

This is also an easy way to verify checksums when downloading files from the internet which list their MD5 Checksums.

You'll need the Digest::MD5 Perl Module.

Class method to read a binary file and copy it to a byte array.

Use this utility to grab lines from a file. Arguments are the input file, starting ling number and ending line number.

Read a eight bytes in little endian order from the given InputStream and create a long out of them.

Set's a filter for what files to accept when using JFileChooser.

I needed these for a recent project, bits and bytes constants.

Convert a password returned by JPasswordField::getPassword() into a String.

This is a very convenient way to remove all doubles from a List in Java. The only prerequisite is that the elements in the list have proper equals and hashCode methods.

It work by using the constructor of a Set that takes a Collection as an argument.

I poured the snippet in a little program so can run it straight away.

What is Dijkstra Algorithm? click on the link above and first understand what the algorithm is all about. in short it calculates the shortest path from A to F or vise versa. This code i can guarantee is the simplest and easiest code to understand. just search on google and try to compare this code and other dijkstra code and you will see what i am talking about. i spent alot of time myself and my instructor to guide me on the rite path.
http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm(Description)
to see how the algorithm really works go on this website it tells you step by step how to update the cost and which path to choose.
http://renaud.waldura.com/doc/java/dijkstra/
Please give some time to understand the algorithm first and then you can see my code. if you done understand the algorithm it is very useless. i know alot of people need Dijkstra algorithm in java for their HW assignment or Test. i am giving you the solution step by step. anyone who wants to understand please go to the url i have posted above and once you have understand then run the code and for those people who just want to copy so that they can get 90% in their test No Problem Here it is .
First open a notepad and name that file anything like data.txt or datas.txt and make sure the file looks something like this and in this format.
0 3 100 5 100 100 (100 represents infinity)
3 0 6 7 7 100
100 6 0 5 5 3
5 7 5 0 1 100
100 7 5 1 0 2
100 100 3 100 2 0
i name this file as a data.txt file. i have 6 nodes. and A is always the starting node which has the cost of 0 so by looking at the first line i
know that A to A have distance 0, A to B is 3, A to c is Infinity, A to D is 5, A to E is Infinity(means no edge connected with A), A to F is Infinity.
for second line(B to A is 3, and then vise versa) and for the 3rd line it starts for C and etc..
save the txt file by any name and then copy the code which i have posted and then to run type this:
javac routing.java
java routing data.txt
you will get the output. i will say this one more time understand how the algorithm works or ......................

Log4J is a really nice Library that aims to facilitate outputting debugging information, but also relevant data, in Java applications. It is highly configurable, using both Categories and Class-Based rules, so that developers can narrow down the problems very well when debugging applications.