question: public static int indexOf ( byte [ ] src , byte [ ] target , int fromIdx ) { final int to = src . length - target . length + 1 ; for ( int i = fromIdx ; i < to ; i ++ ) { if ( src [ i ] == target [ 0 ] ) { boolean equals = true ; for ( int j = 1 , k = i + 1 ; j < target . length && equals ; j ++ , k ++ ) { if ( src [ k ] != target [ j ] ) { equals = false ; } } if ( equals ) { return i ; } } } return - 1 ; }
target:  Searches for target bytes in the source bytes.