Add another cc.ryanc.halo.repository.base.BaseRepository.findAllByIdIn(java.lang.Iterable<ID>, org.springframework.data.domain.Pageable) common method

src/main/java/cc/ryanc/halo/repository/base/BaseRepository.java

@@ -1,5 +1,7 @@
 package cc.ryanc.halo.repository.base;
 
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.repository.NoRepositoryBean;
@@ -18,7 +20,7 @@ import java.util.List;
 public interface BaseRepository<DOMAIN, ID> extends JpaRepository<DOMAIN, ID> {
 
     /**
-     * Finds all domain by id list and the specified sort.
+     * Finds all domain by id list.
      *
      * @param ids  id list of domain must not be null
      * @param sort the specified sort must not be null
@@ -27,6 +29,16 @@ public interface BaseRepository<DOMAIN, ID> extends JpaRepository<DOMAIN, ID> {
     @NonNull
     List<DOMAIN> findAllByIdIn(@NonNull Iterable<ID> ids, @NonNull Sort sort);
 
+    /**
+     * Finds all domain by domain id list.
+     *
+     * @param ids      must not be null
+     * @param pageable must not be null
+     * @return a list of domains
+     */
+    @NonNull
+    Page<DOMAIN> findAllByIdIn(@NonNull Iterable<ID> ids, @NonNull Pageable pageable);
+
     /**
      * Deletes by id list.
      *

src/main/java/cc/ryanc/halo/repository/base/BaseRepositoryImpl.java

@@ -1,10 +1,14 @@
 package cc.ryanc.halo.repository.base;
 
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
 import org.springframework.data.jpa.domain.Specification;
 import org.springframework.data.jpa.repository.support.JpaEntityInformation;
 import org.springframework.data.jpa.repository.support.SimpleJpaRepository;
+import org.springframework.data.repository.support.PageableExecutionUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
@@ -45,23 +49,45 @@ public class BaseRepositoryImpl<DOMAIN, ID> extends SimpleJpaRepository<DOMAIN,
     @Override
     public List<DOMAIN> findAllByIdIn(Iterable<ID> ids, Sort sort) {
         Assert.notNull(ids, "The given Iterable of Id's must not be null!");
+        Assert.notNull(sort, "Sort info must nto be null");
 
         log.debug("Customized findAllById method was invoked");
 
         if (!ids.iterator().hasNext()) {
             return Collections.emptyList();
         }
-        if (!this.entityInformation.hasCompositeId()) {
+
-            ByIdsSpecification<DOMAIN> specification = new ByIdsSpecification<>(this.entityInformation);
+        if (entityInformation.hasCompositeId()) {
-            TypedQuery<DOMAIN> query = super.getQuery(specification, sort);
-            return query.setParameter(specification.parameter, ids).getResultList();
-        } else {
             List<DOMAIN> results = new ArrayList<>();
-
             ids.forEach(id -> super.findById(id).ifPresent(results::add));
-
             return results;
         }
+
+        ByIdsSpecification<DOMAIN> specification = new ByIdsSpecification<>(entityInformation);
+        TypedQuery<DOMAIN> query = super.getQuery(specification, sort);
+        return query.setParameter(specification.parameter, ids).getResultList();
+    }
+
+    @Override
+    public Page<DOMAIN> findAllByIdIn(Iterable<ID> ids, Pageable pageable) {
+        Assert.notNull(ids, "The given Iterable of Id's must not be null!");
+        Assert.notNull(pageable, "Page info must nto be null");
+
+        if (!ids.iterator().hasNext()) {
+            return new PageImpl<>(Collections.emptyList());
+        }
+
+        if (entityInformation.hasCompositeId()) {
+            throw new UnsupportedOperationException("Unsupported find all by composite id with page info");
+        }
+
+        ByIdsSpecification<DOMAIN> specification = new ByIdsSpecification<>(entityInformation);
+        TypedQuery<DOMAIN> query = super.getQuery(specification, pageable).setParameter(specification.parameter, ids);
+        TypedQuery<Long> countQuery = getCountQuery(specification, getDomainClass()).setParameter(specification.parameter, ids);
+
+        return pageable.isUnpaged() ?
+                new PageImpl<>(query.getResultList())
+                : readPage(query, getDomainClass(), pageable, countQuery);
     }
 
     /**
@@ -84,6 +110,17 @@ public class BaseRepositoryImpl<DOMAIN, ID> extends SimpleJpaRepository<DOMAIN,
         return domains.size();
     }
 
+    protected <S extends DOMAIN> Page<S> readPage(TypedQuery<S> query, Class<S> domainClass, Pageable pageable, TypedQuery<Long> countQuery) {
+
+        if (pageable.isPaged()) {
+            query.setFirstResult((int) pageable.getOffset());
+            query.setMaxResults(pageable.getPageSize());
+        }
+
+        return PageableExecutionUtils.getPage(query.getResultList(), pageable,
+                () -> executeCountQuery(countQuery));
+    }
+
     private static final class ByIdsSpecification<T> implements Specification<T> {
         private static final long serialVersionUID = 1L;
         private final JpaEntityInformation<T, ?> entityInformation;
@@ -101,4 +138,24 @@ public class BaseRepositoryImpl<DOMAIN, ID> extends SimpleJpaRepository<DOMAIN,
             return path.in(this.parameter);
         }
     }
+
+    /**
+     * Executes a count query and transparently sums up all values returned.
+     *
+     * @param query must not be {@literal null}.
+     * @return
+     */
+    private static long executeCountQuery(TypedQuery<Long> query) {
+
+        Assert.notNull(query, "TypedQuery must not be null!");
+
+        List<Long> totals = query.getResultList();
+        long total = 0L;
+
+        for (Long element : totals) {
+            total += element == null ? 0 : element;
+        }
+
+        return total;
+    }
 }