[BAEL-2048] Introduction to Spring Data JPA article

spring-data-jpa/src/test/java/org/baeldung/persistence/service/AbstractServicePersistenceIntegrationTest.java

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+package org.baeldung.persistence.service;
+
+import org.baeldung.persistence.IOperations;
+import org.baeldung.persistence.model.Foo;
+import org.baeldung.util.IDUtil;
+import org.hamcrest.Matchers;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.springframework.dao.DataAccessException;
+
+import java.io.Serializable;
+import java.util.List;
+
+import static org.apache.commons.lang3.RandomStringUtils.randomAlphabetic;
+import static org.hamcrest.Matchers.hasItem;
+import static org.hamcrest.Matchers.not;
+import static org.junit.Assert.*;
+
+public abstract class AbstractServicePersistenceIntegrationTest<T extends Serializable> {
+
+    // tests
+
+    // find - one
+
+    @Test
+    /**/public final void givenResourceDoesNotExist_whenResourceIsRetrieved_thenNoResourceIsReceived() {
+        // When
+        final Foo createdResource = getApi().findOne(IDUtil.randomPositiveLong());
+
+        // Then
+        assertNull(createdResource);
+    }
+
+    @Test
+    public void givenResourceExists_whenResourceIsRetrieved_thenNoExceptions() {
+        final Foo existingResource = persistNewEntity();
+        getApi().findOne(existingResource.getId());
+    }
+
+    @Test
+    public void givenResourceDoesNotExist_whenResourceIsRetrieved_thenNoExceptions() {
+        getApi().findOne(IDUtil.randomPositiveLong());
+    }
+
+    @Test
+    public void givenResourceExists_whenResourceIsRetrieved_thenTheResultIsNotNull() {
+        final Foo existingResource = persistNewEntity();
+        final Foo retrievedResource = getApi().findOne(existingResource.getId());
+        assertNotNull(retrievedResource);
+    }
+
+    @Test
+    public void givenResourceExists_whenResourceIsRetrieved_thenResourceIsRetrievedCorrectly() {
+        final Foo existingResource = persistNewEntity();
+        final Foo retrievedResource = getApi().findOne(existingResource.getId());
+        assertEquals(existingResource, retrievedResource);
+    }
+
+    // find - one - by name
+
+    // find - all
+
+    @Test
+    /**/public void whenAllResourcesAreRetrieved_thenNoExceptions() {
+        getApi().findAll();
+    }
+
+    @Test
+    /**/public void whenAllResourcesAreRetrieved_thenTheResultIsNotNull() {
+        final List<Foo> resources = getApi().findAll();
+
+        assertNotNull(resources);
+    }
+
+    @Test
+    /**/public void givenAtLeastOneResourceExists_whenAllResourcesAreRetrieved_thenRetrievedResourcesAreNotEmpty() {
+        persistNewEntity();
+
+        // When
+        final List<Foo> allResources = getApi().findAll();
+
+        // Then
+        assertThat(allResources, not(Matchers.<Foo> empty()));
+    }
+
+    @Test
+    /**/public void givenAnResourceExists_whenAllResourcesAreRetrieved_thenTheExistingResourceIsIndeedAmongThem() {
+        final Foo existingResource = persistNewEntity();
+
+        final List<Foo> resources = getApi().findAll();
+
+        assertThat(resources, hasItem(existingResource));
+    }
+
+    @Test
+    /**/public void whenAllResourcesAreRetrieved_thenResourcesHaveIds() {
+        persistNewEntity();
+
+        // When
+        final List<Foo> allResources = getApi().findAll();
+
+        // Then
+        for (final Foo resource : allResources) {
+            assertNotNull(resource.getId());
+        }
+    }
+
+    // create
+
+    @Test(expected = RuntimeException.class)
+    /**/public void whenNullResourceIsCreated_thenException() {
+        getApi().create(null);
+    }
+
+    @Test
+    /**/public void whenResourceIsCreated_thenNoExceptions() {
+        persistNewEntity();
+    }
+
+    @Test
+    /**/public void whenResourceIsCreated_thenResourceIsRetrievable() {
+        final Foo existingResource = persistNewEntity();
+
+        assertNotNull(getApi().findOne(existingResource.getId()));
+    }
+
+    @Test
+    /**/public void whenResourceIsCreated_thenSavedResourceIsEqualToOriginalResource() {
+        final Foo originalResource = createNewEntity();
+        final Foo savedResource = getApi().create(originalResource);
+
+        assertEquals(originalResource, savedResource);
+    }
+
+    @Test(expected = RuntimeException.class)
+    public void whenResourceWithFailedConstraintsIsCreated_thenException() {
+        final Foo invalidResource = createNewEntity();
+        invalidate(invalidResource);
+
+        getApi().create(invalidResource);
+    }
+
+    /**
+     * -- specific to the persistence engine
+     */
+    @Test(expected = DataAccessException.class)
+    @Ignore("Hibernate simply ignores the id silently and still saved (tracking this)")
+    public void whenResourceWithIdIsCreated_thenDataAccessException() {
+        final Foo resourceWithId = createNewEntity();
+        resourceWithId.setId(IDUtil.randomPositiveLong());
+
+        getApi().create(resourceWithId);
+    }
+
+    // update
+
+    @Test(expected = RuntimeException.class)
+    /**/public void whenNullResourceIsUpdated_thenException() {
+        getApi().update(null);
+    }
+
+    @Test
+    /**/public void givenResourceExists_whenResourceIsUpdated_thenNoExceptions() {
+        // Given
+        final Foo existingResource = persistNewEntity();
+
+        // When
+        getApi().update(existingResource);
+    }
+
+    /**
+     * - can also be the ConstraintViolationException which now occurs on the update operation will not be translated; as a consequence, it will be a TransactionSystemException
+     */
+    @Test(expected = RuntimeException.class)
+    public void whenResourceIsUpdatedWithFailedConstraints_thenException() {
+        final Foo existingResource = persistNewEntity();
+        invalidate(existingResource);
+
+        getApi().update(existingResource);
+    }
+
+    @Test
+    /**/public void givenResourceExists_whenResourceIsUpdated_thenUpdatesArePersisted() {
+        // Given
+        final Foo existingResource = persistNewEntity();
+
+        // When
+        change(existingResource);
+        getApi().update(existingResource);
+
+        final Foo updatedResource = getApi().findOne(existingResource.getId());
+
+        // Then
+        assertEquals(existingResource, updatedResource);
+    }
+
+    // delete
+
+    // @Test(expected = RuntimeException.class)
+    // public void givenResourceDoesNotExists_whenResourceIsDeleted_thenException() {
+    // // When
+    // getApi().delete(IDUtil.randomPositiveLong());
+    // }
+    //
+    // @Test(expected = RuntimeException.class)
+    // public void whenResourceIsDeletedByNegativeId_thenException() {
+    // // When
+    // getApi().delete(IDUtil.randomNegativeLong());
+    // }
+    //
+    // @Test
+    // public void givenResourceExists_whenResourceIsDeleted_thenNoExceptions() {
+    // // Given
+    // final Foo existingResource = persistNewEntity();
+    //
+    // // When
+    // getApi().delete(existingResource.getId());
+    // }
+    //
+    // @Test
+    // /**/public final void givenResourceExists_whenResourceIsDeleted_thenResourceNoLongerExists() {
+    // // Given
+    // final Foo existingResource = persistNewEntity();
+    //
+    // // When
+    // getApi().delete(existingResource.getId());
+    //
+    // // Then
+    // assertNull(getApi().findOne(existingResource.getId()));
+    // }
+
+    // template method
+
+    protected Foo createNewEntity() {
+        return new Foo(randomAlphabetic(6));
+    }
+
+    protected abstract IOperations<Foo> getApi();
+
+    private final void invalidate(final Foo entity) {
+        entity.setName(null);
+    }
+
+    private final void change(final Foo entity) {
+        entity.setName(randomAlphabetic(6));
+    }
+
+    protected Foo persistNewEntity() {
+        return getApi().create(createNewEntity());
+    }
+
+}

spring-data-jpa/src/test/java/org/baeldung/persistence/service/FooServicePersistenceIntegrationTest.java

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+package org.baeldung.persistence.service;
+
+import org.baeldung.persistence.IOperations;
+import org.baeldung.persistence.model.Foo;
+import org.baeldung.spring.PersistenceConfig;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.dao.InvalidDataAccessApiUsageException;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.support.AnnotationConfigContextLoader;
+
+import static org.apache.commons.lang3.RandomStringUtils.randomAlphabetic;
+import static org.junit.Assert.assertNotNull;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = { PersistenceConfig.class }, loader = AnnotationConfigContextLoader.class)
+public class FooServicePersistenceIntegrationTest extends AbstractServicePersistenceIntegrationTest<Foo> {
+
+    @Autowired
+    private IFooService service;
+
+    // tests
+
+    @Test
+    public final void whenContextIsBootstrapped_thenNoExceptions() {
+        //
+    }
+
+    @Test
+    public final void whenEntityIsCreated_thenNoExceptions() {
+        service.create(new Foo(randomAlphabetic(6)));
+    }
+
+    @Test(expected = DataIntegrityViolationException.class)
+    public final void whenInvalidEntityIsCreated_thenDataException() {
+        service.create(new Foo());
+    }
+
+    @Test(expected = DataIntegrityViolationException.class)
+    public final void whenEntityWithLongNameIsCreated_thenDataException() {
+        service.create(new Foo(randomAlphabetic(2048)));
+    }
+
+    // custom Query method
+
+    @Test
+    public final void givenUsingCustomQuery_whenRetrievingEntity_thenFound() {
+        final String name = randomAlphabetic(6);
+        service.create(new Foo(name));
+
+        final Foo retrievedByName = service.retrieveByName(name);
+        assertNotNull(retrievedByName);
+    }
+
+    // work in progress
+
+    @Test(expected = InvalidDataAccessApiUsageException.class)
+    @Ignore("Right now, persist has saveOrUpdate semantics, so this will no longer fail")
+    public final void whenSameEntityIsCreatedTwice_thenDataException() {
+        final Foo entity = new Foo(randomAlphabetic(8));
+        service.create(entity);
+        service.create(entity);
+    }
+
+    // API
+
+    @Override
+    protected final IOperations<Foo> getApi() {
+        return service;
+    }
+
+}

spring-data-jpa/src/test/java/org/baeldung/util/IDUtil.java

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+package org.baeldung.util;
+
+import java.util.Random;
+
+public final class IDUtil {
+
+    private IDUtil() {
+        throw new AssertionError();
+    }
+
+    // API
+
+    public static String randomPositiveLongAsString() {
+        return Long.toString(randomPositiveLong());
+    }
+
+    public static String randomNegativeLongAsString() {
+        return Long.toString(randomNegativeLong());
+    }
+
+    public static long randomPositiveLong() {
+        long id = new Random().nextLong() * 10000;
+        id = (id < 0) ? (-1 * id) : id;
+        return id;
+    }
+
+    private static long randomNegativeLong() {
+        long id = new Random().nextLong() * 10000;
+        id = (id > 0) ? (-1 * id) : id;
+        return id;
+    }
+
+}