Java Pthread to search text file

Using Java and Pthreads, I need the following: ** Number of threads as a variable ** 1. I have a huge text file "space delimited" -- each line has a different size -- each line ends with a space -- each line represents a transaction with products IDs 2. I need to count the occurrence of each pair of items in all transactions (A,B) "example: number of lines that have IDs 4 & 9" 3. I need to count the occurrence of all 3 items together (A,B,C) "example: number of lines that have IDs 4 & 9 & 17" 4. Get the Maximum occurrence in the file of (A,B) and show the values of A & B 5. Get the Maximum occurrence in the file of (A,B,C) and show the values of A & B & C