Create closed and not overlapping time intervals from time stamps

I need a java algorithms with a fitting java pattern: I have a table with two type of timestamps. (columns: TIMESTAMP, TYPE). One timestamp type (record in table) represents a begin of an interval and the other type an end of an interval. I need to transform this table into another table (colums: BEGINTIME, ENDTIME). After the transformation the second table should store closed and not overlapping intervals. IMPORTANT!!! I have to consider different uses cases, e.g. when one timestamp is after 24:00 then take 24:00 instead of 1:00. The algorithmus should use a fitting pattern where I can add further use cases without change old use cases like checking a test chain consisting of several uses cases. It should be batch application looping over not transformed timestamps (1st table). The batch application should use Parallel stream processing in order to scale. So that the 1st table can be transformed very fast. It should use a watchdog pattern, supervising the transforming thread (s). With log4J. Data should be stored in postgreSQL database. The batch should run on Redhat Linux. With Maven in Eclipse. Plain JDBC templates, no hibernate or mybatis. It should have DAO layer and a layer for the business logic.