HI!GUYS!I have got a problem about Minecraft Java Programming! Help me!

I am creating my own mod using Java. I want to read data from text file or other format file and use the data to create a model maybe a tooth, however, the read/write codes seem be useless and Java crash every time I write read/write in my class. Could you guys help me? I know python use .csv to to do this, how about Java?

In my generation class I have:

public class StructureGenerator implements IWorldGenerator { .....

                      Readbyte byt=new Readbyte();

                      int[] a=byt.readAlternateImpl("sphere.byt");

                        ....}

Readbyte is the class I write to read out a .byt file to a int array. Then I use the value in array to decide what kind of block I want to create.