Item B-03526: As a Manager, I wold like to sort services in the service management table

The ServiceSpecification is implemented to provide sorting and pagination.

The AbstracSpecification used a default 'lastModified' order by, which does not exist in the ServiceRepo.
To prevent breakage, the the order by assignment was move into its own function, toPredicateDefaultQueryOrderBy().
This allows for the ServiceSpecification, as an exception, to not attempt to order by "lastModified" by overriding that new method.

Author: kaladay

src/main/java/edu/tamu/app/controller/ServiceController.java

@@ -17,6 +17,7 @@
 import edu.tamu.app.model.Service;
 import edu.tamu.app.model.repo.IdeaRepo;
 import edu.tamu.app.model.repo.ServiceRepo;
+import edu.tamu.app.model.request.FilteredPageRequest;
 import edu.tamu.app.model.request.IssueRequest;
 import edu.tamu.app.model.request.ServiceRequest;
 import edu.tamu.app.service.ProjectService;
@@ -52,6 +53,12 @@ public ApiResponse getPublicServices() {
         return new ApiResponse(SUCCESS, serviceRepo.findByIsPublicOrderByStatusDescNameAsc(true));
     }
 
+    @RequestMapping("/page")
+    @PreAuthorize("hasRole('ANONYMOUS')")
+    public ApiResponse page(@RequestBody FilteredPageRequest filteredPageRequest) {
+        return new ApiResponse(SUCCESS, serviceRepo.findAll(filteredPageRequest.getServiceSpecification(), filteredPageRequest.getPageRequest()));
+    }
+
     @RequestMapping("/{id}")
     @PreAuthorize("hasRole('ANONYMOUS')")
     public ApiResponse getService(@PathVariable Long id) {

src/main/java/edu/tamu/app/model/repo/ServiceRepo.java

@@ -2,6 +2,9 @@
 
 import java.util.List;
 
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.jpa.domain.Specification;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import edu.tamu.app.enums.Status;
@@ -10,6 +13,8 @@
 
 public interface ServiceRepo extends JpaRepository<Service, Long>, ServiceRepoCustom {
 
+    public Page<Service> findAll(Specification<Service> specification, Pageable pageable);
+
     public List<Service> findByIsPublicOrderByStatusDescNameAsc(Boolean isPublic);
 
     public List<Service> findByIsAuto(Boolean isAuto);

src/main/java/edu/tamu/app/model/repo/specification/AbstractSpecification.java

@@ -49,11 +49,18 @@ public Predicate toPredicate(Root<E> root, CriteriaQuery<?> query, CriteriaBuild
             }
         }
 
-        query.orderBy(cb.desc(root.get("lastModified")));
+        toPredicateDefaultQueryOrderBy(root, query, cb);
 
         return builder.build(cb);
     }
 
+    /**
+     * Allow implementing classes to control order by in case lastModified is non-existent.
+     */
+    protected void toPredicateDefaultQueryOrderBy(Root<E> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
+        query.orderBy(cb.desc(root.get("lastModified")));
+    }
+
     private class PredicateBuilder {
 
         private final Map<String, List<Predicate>> predicates;

src/main/java/edu/tamu/app/model/repo/specification/ServiceSpecification.java

@@ -0,0 +1,19 @@
+package edu.tamu.app.model.repo.specification;
+
+import java.util.Map;
+
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.Root;
+
+public class ServiceSpecification<E> extends AbstractSpecification<E> {
+
+    public ServiceSpecification(Map<String, String[]> filters) {
+        super(filters);
+    }
+
+    @Override
+    protected void toPredicateDefaultQueryOrderBy(Root<E> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
+        query.orderBy(cb.desc(root.get("name")));
+    }
+}

src/main/java/edu/tamu/app/model/request/FilteredPageRequest.java

@@ -13,9 +13,11 @@
 import edu.tamu.app.model.FeatureProposal;
 import edu.tamu.app.model.Idea;
 import edu.tamu.app.model.Note;
+import edu.tamu.app.model.Service;
 import edu.tamu.app.model.repo.specification.FeatureProposalSpecification;
 import edu.tamu.app.model.repo.specification.IdeaSpecification;
 import edu.tamu.app.model.repo.specification.NoteSpecification;
+import edu.tamu.app.model.repo.specification.ServiceSpecification;
 
 public class FilteredPageRequest {
 
@@ -42,6 +44,11 @@ public IdeaSpecification<Idea> getIdeaSpecification() {
         return new IdeaSpecification<Idea>(filters);
     }
 
+    @JsonIgnore
+    public ServiceSpecification<Service> getServiceSpecification() {
+        return new ServiceSpecification<Service>(filters);
+    }
+
     @JsonIgnore
     public FeatureProposalSpecification<FeatureProposal> getFeatureProposalSpecification() {
         return new FeatureProposalSpecification<FeatureProposal>(filters);