java – Separate sentences in paragraph that doesn’t have punctuation

How can I separate sentences in paragraph that doesn’t have punctuation?

For example, I have this paragraph:

The red glint of paint sparkled under the sun he had dreamed of
owning this car since he was ten and that dream had become a reality
less than a year ago it was his baby and he spent hours caring for
it pampering it and fondling over it she knew this all too well
and that’s exactly why she had taken a sludge hammer to it

I need the output to be something like this:

The red glint of paint sparkled under the sun. He had dreamed of
owning this car since he was ten and that dream had become a reality
less than a year ago. It was his baby and he spent hours caring for
it pampering it and fondling over it. She knew this all too well
and that’s exactly why she had taken a sludge hammer to it.

I just need to add punctuations to separate the sentences int the paragraph, I don’t need to add commas.

Is there any ideas or keywords that would help me with this problem?