How to make a Java File Reader

How to make a Java File Reader

I'm trying to make a word scrambler for a project in class. It needs to
read in a .txt file and output a String with all of the words in the file;
but scrambled. for example:
Tihs is how the wrdos sulohd be sarcmbeld.
Ignoring punctuation and leaving the first and last letter in place.
I'm having trouble reading in the file into an array. I was planning on
using collections.shuffle to shuffle the inner layers by ignoring the
first and last letter and randomizing the inner letters.
I dont know how to impliment the file reader, but here is my scrambler for
each word.
public static String shuffle(String input){
input = "supercalifragilisticexpialidocious";
int i = 0;
ArrayList<Character> chars = new
ArrayList<Character>(input.length());
String output = "";
char[] characters = input.toCharArray();
char[] newWord = new char[input.length()];
newWord[0] = characters[0];
newWord[input.length()-1] = characters[input.length()-1];
for (i=1; i < input.length()-1;i++ ) {
chars.add(characters[i]);
}
System.out.println(chars);
for (i = 1; i <= input.length()-2; i++)
{
Collections.shuffle(chars);
}
Character[] middle = chars.toArray(new Character[chars.size()]);
for (i = 1; i < newWord.length - 2; i++)
{
newWord[i] = middle[i];
}
System.out.println(newWord);
StringBuffer r= new StringBuffer(output);
for (i = 0; i < newWord.length-1; i++)
{
r.append(newWord[i]);
}
return output;
}
This outputs saxupieipclflaurrtocslcidigaiiois like i want, but now i need
a way to read the .txt file in and split it into separate words.
If anyone can help me that would be great. What I'm really looking for is
if someone can help me with making a file reader for this.