Ankur Mhatre
7b06d653e4
Adds a JUnit test suite (GetVsGetReferenceTest, MergeRefreshTest, OptimisticLockTest, IdentityBatchTest, SequenceBatchTest, AllocationSizeSweepTest, BatchSizeSweepTest) so every surprising behavior described in the three companion posts has a reproducible test, alongside the original CommandLineRunner scenarios. Rewrites all three doc chapters and the README around the new experiments: the get()/getReference() same-session matrix, the merge()/refresh() experiments (including exactly when OptimisticLockException surfaces and a corrected LAZY-plus- cascade merge() result), and two new sweeps (allocationSize, batch_size) for batch inserts.
52 lines
1.9 KiB
Java
52 lines
1.9 KiB
Java
package com.ankurm.hibernatedemo;
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import static org.assertj.core.api.Assertions.assertThat;
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import com.ankurm.hibernatedemo.model.WidgetSequence;
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import jakarta.persistence.EntityManager;
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import jakarta.persistence.EntityManagerFactory;
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import org.hibernate.SessionFactory;
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import org.hibernate.stat.Statistics;
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import org.junit.jupiter.api.Test;
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import org.springframework.beans.factory.annotation.Autowired;
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import org.springframework.boot.test.context.SpringBootTest;
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/**
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* Backs ankurm.com post 4861. Docs: docs/03-inserting-objects.md.
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* Run with {@code ./mvnw -Dtest=SequenceBatchTest test}.
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*
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* <p>{@link WidgetSequence} sets {@code allocationSize = 25}, matching
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* {@code hibernate.jdbc.batch_size} in application.yml. See {@code AllocationSizeSweepTest} for
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* what happens when the two are deliberately mismatched.
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*/
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@SpringBootTest
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class SequenceBatchTest {
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private static final int ROW_COUNT = 30;
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@Autowired
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private EntityManagerFactory emf;
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@Test
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void sequenceGeneratorAllowsBatching_fourPreparedStatementsForThirtyRows() {
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SessionFactory sessionFactory = emf.unwrap(SessionFactory.class);
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Statistics stats = sessionFactory.getStatistics();
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stats.clear();
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EntityManager em = emf.createEntityManager();
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em.getTransaction().begin();
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for (int i = 1; i <= ROW_COUNT; i++) {
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em.persist(new WidgetSequence("sequence-" + i));
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}
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em.getTransaction().commit();
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em.close();
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assertThat(stats.getEntityInsertCount()).isEqualTo(ROW_COUNT);
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assertThat(stats.getPrepareStatementCount())
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.as("30 rows at batch_size=25 is 2 insert batches (25 + 5); allocationSize=25 "
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+ "means the first 25 ids come from one sequence call and the remaining "
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+ "5 force a second -- 2 insert batches + 2 sequence calls = 4")
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.isEqualTo(4);
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}
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}
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