How to add data to json file?

Question

Java

Good evening.
The question is as follows:
there is a need to process a large amount of data for a long time and tear out some information, write it into json documents. There is no possibility to store all the data in memory, and then write all the information once, since there is a monstrously large amount of data. I would also like to do without a buffer - some kind of text file into which to write information, and then read it again and write it to Json. Another pitfall - json documents need to be replaced with new ones when approaching 5 mb, i.e. the case is not limited to one copy.
What is the most elegant solution anyone could suggest in this situation?