parsing - What is the best way to read a file in Java? -

i writing java program simulate assembler (as assignment in college).

i have assembly program given input assembler.

the general format of every statement in assembly code follows:

[label] opcode operand1 [operand2] (each term separated space)

label , operand2 optional parts in statements these may unavailable.

in java code read each line , use stringtokenizer 4 parts separated spaces.

my question whenever label and/or operand2 not available how can find out first values returned stringtokenizer opcode value , second value operand1 value? best way this?

thanks lot

if

1. a label can never opcode,
2. and depending how many opcode values exist,

you might create method isopcode(string s) , test first part after tokenizing. if passes, label must have been missing. if fails, label must exist.

depending on results of test, can count remaining parts determine if operand2 present.