The google-diff-match-path library seems to provide the functionality you need. Here's a demo of it in action.

Exactly what FileUtils.contentEquals method of Apache commons IO does and api is here.

Try something like:

File file1 = new File("file1.txt");
File file2 = new File("file2.txt");
boolean isTwoEqual = FileUtils.contentEquals(file1, file2);

It does the following checks before actually doing the comparison:

• existence of both the files
• Both file's that are passed are to be of file type and not directory.
• length in bytes should be the same.
• Both are different files and not one and the same.
• Then compare the contents.