Chunkwork

Simple Java utility for breaking tasks into smaller tasks

Chunker helps you break down a large unit of work into smaller discrete serial units of work. Take the following example:

public void delete(final List<Integer> employeeIds) {
  Chunker.execute(employeeIds, 50, chunk -> {
      getSession()
        .createSQLQuery("delete from Employee where employeeId in (:employeeIds)")
        .setParameterList("employeeIds", chunk)
        .executeUpdate();
    });
}

In this circumstance, a database specific IN clause limit exceeded error can be avoided because the SQL inputs are chunked into multiple blocks of 50. Given a list of 130 employee IDs, the SQL statement above would be executed 3 times with distinct blocks of IDs (50 + 50 + 30).

In this example we print the numbers 1 - 64 to the terminal in a nice 8 x 8 grid:

Chunker.execute(IntStream.range(0, 64)
                .boxed()
                .map(i -> String.format("%03x", i))
                .toList(),
        8,
        System.out::println);

// Output
[000, 001, 002, 003, 004, 005, 006, 007]
[008, 009, 00a, 00b, 00c, 00d, 00e, 00f]
[010, 011, 012, 013, 014, 015, 016, 017]
[018, 019, 01a, 01b, 01c, 01d, 01e, 01f]
[020, 021, 022, 023, 024, 025, 026, 027]
[028, 029, 02a, 02b, 02c, 02d, 02e, 02f]
[030, 031, 032, 033, 034, 035, 036, 037]
[038, 039, 03a, 03b, 03c, 03d, 03e, 03f]

jonathancone/chunkwork

Chunkwork