Polishing.

Extract method in order to make the code more readable.

Switch to #xxx syntax for issue numbers instead of gh-xxx.

Original pull request #939

Author: schauder

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/convert/DefaultDataAccessStrategy.java

@@ -124,30 +124,34 @@ public <T> Object insert(T instance, Class<T> domainType, Identifier identifier)
 		String insertSql = sqlGenerator.getInsert(new HashSet<>(parameterSource.getIdentifiers()));
 
 		if (idValue == null) {
+			return executeInsertAndReturnGeneratedId(domainType, persistentEntity, parameterSource, insertSql);
+		} else {
 
-			KeyHolder holder = new GeneratedKeyHolder();
+			operations.update(insertSql, parameterSource);
+			return null;
+		}
+	}
 
-			IdGeneration idGeneration = sqlGeneratorSource.getDialect().getIdGeneration();
+	@Nullable
+	private <T> Object executeInsertAndReturnGeneratedId(Class<T> domainType, RelationalPersistentEntity<T> persistentEntity, SqlIdentifierParameterSource parameterSource, String insertSql) {
 
-			if (idGeneration.driverRequiresKeyColumnNames()) {
+		KeyHolder holder = new GeneratedKeyHolder();
 
-				String[] keyColumnNames = getKeyColumnNames(domainType);
-				if (keyColumnNames.length == 0) {
-					operations.update(insertSql, parameterSource, holder);
-				} else {
-					operations.update(insertSql, parameterSource, holder, keyColumnNames);
-				}
-			} else {
+		IdGeneration idGeneration = sqlGeneratorSource.getDialect().getIdGeneration();
+
+		if (idGeneration.driverRequiresKeyColumnNames()) {
+
+			String[] keyColumnNames = getKeyColumnNames(domainType);
+			if (keyColumnNames.length == 0) {
 				operations.update(insertSql, parameterSource, holder);
+			} else {
+				operations.update(insertSql, parameterSource, holder, keyColumnNames);
 			}
-
-			return getIdFromHolder(holder, persistentEntity);
+		} else {
+			operations.update(insertSql, parameterSource, holder);
 		}
-		else {
 
-			operations.update(insertSql, parameterSource);
-			return null;
-		}
+		return getIdFromHolder(holder, persistentEntity);
 	}
 
 	/*
@@ -462,6 +466,10 @@ private <S, T> SqlIdentifierParameterSource getParameterSource(@Nullable S insta
 		return parameters;
 	}
 
+	/**
+	 * Returns the id value if its not a primitive zero. Returns {@literal null} if the id value is null or a primitive
+	 * zero.
+	 */
 	@Nullable
 	@SuppressWarnings("unchecked")
 	private <S, ID> ID getIdValueOrNull(S instance, RelationalPersistentEntity<S> persistentEntity) {

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/convert/DefaultDataAccessStrategyUnitTests.java

@@ -193,7 +193,7 @@ public void considersConfiguredWriteConverterForIdValueObjectsWhichReferencedInO
 		assertThat(paramSourceCaptor.getValue().getValue("DUMMYENTITYROOT")).isEqualTo(rawId);
 	}
 
-	@Test // gh-933
+	@Test // #933
 	public void insertWithDefinedIdDoesNotRetrieveGeneratedKeys() {
 
 		Object generatedId = accessStrategy.insert(new DummyEntity(ORIGINAL_ID), DummyEntity.class, Identifier.from(additionalParameters));
@@ -204,7 +204,7 @@ public void insertWithDefinedIdDoesNotRetrieveGeneratedKeys() {
 				paramSourceCaptor.capture());
 	}
 
-	@Test // gh-933
+	@Test // #933
 	public void insertWithUndefinedIdRetrievesGeneratedKeys() {
 
 		when(namedJdbcOperations.update(any(), any(), any()))

spring-data-relational/src/test/java/org/springframework/data/relational/core/sql/ConditionsUnitTests.java

@@ -24,7 +24,7 @@
  */
 class ConditionsUnitTests {
 
-	@Test // gh-916
+	@Test // #916
 	void notInOfColumnAndExpression() {
 
 		Table table = Table.create("t");