string replaceall occurences with strings inside arrays

Let our string be a sentence that contains several unique terms, such as

"person1: hello, person2! person3, are you the same person as person4?"

I would like to replace person1, person2, person 3, and person4 with strings I have in a text file. In the text file, this would be an example of what it looks like:

person1=example1
person2=example2
person3=example3
person4=example3

NOTICE how person3 and person4 have the same replacer term - also, I have a bufferedreader that puts the entire text file into an array, lets name it "example".

How would I have it so that the text gets ALL the elements of array "example" so it can replace the prefix of "=" by the
suffix of "=". So, the final string would look like:

"example1: hello, example2! example3, are you the same as example3?"

Also, note that the size of array "example" is indefinite, as you can add even more lines to the text file.