Re: How to compare two large text files?

In another words, lines 2 to 1101 in text2.xml should be identical with
lines 850 to 1949 in text1.xml; lines 1103 all the way to the end in
text2.xml should be identical with lines from 2799 to the end in
text1.xml.

One way for comparison is using for loop and with these hard-coded line
number, compare line by line. But I hate the hard-coded line number.

I tried the way below, but is too slow:

1)append all the lines in text1.xml into a huge single String line, e.g.
benchLine;
2)append lines 2 to 1101 in text2.xml into another huge String line,
e.g. patternLine;
3)Pattern pattern = Pattern.compile(".*" + patternLine + ".*"); //use
the huge line to generage a regular expression pattern
  pattern.macher(benchLine).find(); //hope it is true
4)repeat step 2) but with lines 1103 to the end in text2.xml and step 3

But this is tooooo slow.