You can run your tests offline with the tools available here. To do this first download and extract the contents of KnightsMoveCipher.zip. There are three files: the corpus, the word list, and the testing tool. To make use of these, you will need to modify your program to read from standard in and write to standard out. When reading the input, the first line will contain the scrambled text. The next line will contain L-1, the number of elements in delta. The following L-1 lines will contain the elements of delta. You should output a single line containing the decrypted text (and flush standard out). In pseudocode, this look like:

    ciphertext = readLine()
    len = int(readLine())
    for(i = 0; i<len; i++){
        delta[i] = int(readLine())
    }
    printLine(decipher(ciphertext,delta))
    flush(stdout)

Note that if you wish to use the contents of the words.txt file, you will have to implement your own getWords function to read and parse it.

Once you have modified your program to read from standard in and write to standard out, you can run it on the command line by running:
java -Xmx1024M -jar KnightsMoveCipher.jar -exec "<command>" -seed <seed>
Here, <command> is the command to your executable, like "java -Xmx1024M KnightsMoveCipher" or ./kmc. <seed> is a seed for the random number generator. Additionally, if you add -output <name>, <name>.png will be generated showing the letters on a grid, colored according to their position in the original text (red is earlier). Finally, if you wish to output debugging statements in your code, you may do so by using standard error. Do not use standard out for this purpose, as it will not work.

You can download the source for this tool also: KnightsMoveCipher.java