ReflectionTestUtils to tweak private fields for unit tests

I was writing an integration test for create in bulk mode which inserts data in bulk if the number of records is over 100.

Now just in order to test this bulk insert feature I do not want to load 100 records. So I need to tweak this batchSize set to 100 to 1

public class DaoImpl {
private static Integer batchSize = 100;

@Autowired
private Dao dao;

public void test()
{
// get the default size
Integer defaultBatchSize = (Integer) ReflectionTestUtils.getField(dao, "batchSize");

// tweak the data
Integer batchSize = 1;
ReflectionTestUtils.setField(dao, "batchSize", batchSize, Integer.class);
assertEquals(batchSize, ReflectionTestUtils.getField(dao, "batchSize"));

// proceed with test

// revert it back to the default size
ReflectionTestUtils.setField(dao, "batchSize", defaultBatchSize, Integer.class);
}

ReflectionTestUtils.setField will internally take care of making your field accessible.