In minecraft 1.3.2 there is a way to create WorldGen files very easily. You can use it to create 80 * 80 castles without having to write any code at all. There are just 2 things that you will need for it.
The first is MCedit. Mcedit is a program used to create and edit your minecraft world very fast. You can download it here.
The second thing you will need is the .schematic to java file converter. This program will code the structure for you once you have made it inside of mcedit. You can download it over here.
To use this you need to extract the file you have downloaded. In the map you get should be a .jar file called SchematicConverter. Try opening this with java. If you are lucky it will open the program and you can go to the next tutorial. If it doesn’t open follow to instructions below.
If java doesn’t open the file when you try running it with java you have to do something a bit harder.
The first thing you have to do is open the command promt named ‘cmd’ or ‘run’.
Now you have to navigate your way to the .jar file you have just extracted. To do this you can use the command ‘dir’. This will show you all the folders and files in the current map.
Use ‘cd foldername’ to enter folders. Use ‘cd C:/’ to get to the center of your pc. Every file you need is accesable from there.
Once you are in the map that contains the SchematicConverter.jar you need to type
‘java -jar SchematicConverter’
This will run the file with java for you.