DATAJPA-1116 - Polishing.

Guard consistently paged/unpaged handling. Fix javadoc.

Original pull request: #203.

src/main/java/org/springframework/data/jpa/repository/JpaSpecificationExecutor.java

@@ -34,8 +34,8 @@ public interface JpaSpecificationExecutor<T> {
 	/**
 	 * Returns a single entity matching the given {@link Specification} or {@link Optional#empty()} if none found.
 	 *
-	 * @param spec can be @literal {@null}.
-	 * @return
+	 * @param spec can be {@literal null}.
+	 * @return never {@literal null}.
 	 * @throws org.springframework.dao.IncorrectResultSizeDataAccessException if more than one entity found.
 	 */
 	Optional<T> findOne(Specification<T> spec);

src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java

@@ -56,7 +56,6 @@ import org.springframework.data.repository.support.PageableExecutionUtils;
 import org.springframework.stereotype.Repository;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.util.Assert;
-import org.springframework.util.ObjectUtils;
 
 /**
  * Default implementation of the {@link org.springframework.data.repository.CrudRepository} interface. This will offer
@@ -346,7 +345,7 @@ public class SimpleJpaRepository<T, ID> implements JpaRepository<T, ID>, JpaSpec
 	 */
 	public Page<T> findAll(Pageable pageable) {
 
-		if (null == pageable) {
+		if (isUnpaged(pageable)) {
 			return new PageImpl<T>(findAll());
 		}
 
@@ -381,7 +380,7 @@ public class SimpleJpaRepository<T, ID> implements JpaRepository<T, ID>, JpaSpec
 	public Page<T> findAll(Specification<T> spec, Pageable pageable) {
 
 		TypedQuery<T> query = getQuery(spec, pageable);
-		return (pageable == null || pageable.isUnpaged()) ? new PageImpl<T>(query.getResultList())
+		return isUnpaged(pageable) ? new PageImpl<T>(query.getResultList())
 				: readPage(query, getDomainClass(), pageable, spec);
 	}
 
@@ -456,7 +455,8 @@ public class SimpleJpaRepository<T, ID> implements JpaRepository<T, ID>, JpaSpec
 		Class<S> probeType = example.getProbeType();
 		TypedQuery<S> query = getQuery(new ExampleSpecification<>(example), probeType, pageable);
 
-		return pageable == null ? new PageImpl<>(query.getResultList()) : readPage(query, probeType, pageable, spec);
+		return isUnpaged(pageable) ? new PageImpl<>(query.getResultList())
+				: readPage(query, probeType, pageable, spec);
 	}
 
 	/*
@@ -529,7 +529,6 @@ public class SimpleJpaRepository<T, ID> implements JpaRepository<T, ID>, JpaSpec
 	 */
 	@Transactional
 	public void flush() {
-
 		em.flush();
 	}
 
@@ -740,6 +739,10 @@ public class SimpleJpaRepository<T, ID> implements JpaRepository<T, ID>, JpaSpec
 		return total;
 	}
 
+	private static boolean isUnpaged(Pageable pageable) {
+		return pageable == null || pageable.isUnpaged();
+	}
+
 	/**
 	 * Specification that gives access to the {@link Parameter} instance used to bind the ids for
 	 * {@link SimpleJpaRepository#findAllById(Iterable)}. Workaround for OpenJPA not binding collections to in-clauses