#109 only one conference for paper

src/main/java/ru/ulstu/paper/model/Paper.java

@@ -3,6 +3,7 @@ package ru.ulstu.paper.model;
 import org.hibernate.annotations.Fetch;
 import org.hibernate.annotations.FetchMode;
 import org.hibernate.validator.constraints.NotBlank;
+import ru.ulstu.conference.model.Conference;
 import ru.ulstu.core.model.BaseEntity;
 import ru.ulstu.core.model.UserContainer;
 import ru.ulstu.deadline.model.Deadline;
@@ -114,6 +115,9 @@ public class Paper extends BaseEntity implements UserContainer {
     @Column(name = "latex_text")
     private String latexText;
 
+    @ManyToMany(mappedBy = "papers")
+    private List<Conference> conferences;
+
     public PaperStatus getStatus() {
         return status;
     }
@@ -218,6 +222,14 @@ public class Paper extends BaseEntity implements UserContainer {
         this.latexText = latexText;
     }
 
+    public List<Conference> getConferences() {
+        return conferences;
+    }
+
+    public void setConferences(List<Conference> conferences) {
+        this.conferences = conferences;
+    }
+
     @Override
     public Set<User> getUsers() {
         return getAuthors();

src/main/java/ru/ulstu/paper/repository/PaperRepository.java

@@ -20,4 +20,8 @@ public interface PaperRepository extends JpaRepository<Paper, Integer> {
     List<Paper> findByTypeAndStatus(Paper.PaperType type, Paper.PaperStatus status);
 
     List<Paper> findByStatusNot(Paper.PaperStatus status);
+
+    List<Paper> findByConferencesIsNullAndStatusNot(Paper.PaperStatus status);
+
+    List<Paper> findByIdNotInAndConferencesIsNullAndStatusNot(List<Integer> paperIds, Paper.PaperStatus status);
 }

src/main/java/ru/ulstu/paper/service/PaperService.java

@@ -242,9 +242,9 @@ public class PaperService {
 
     public List<Paper> findAllNotSelect(List<Integer> paperIds) {
         if (!paperIds.isEmpty()) {
-            return sortPapers(paperRepository.findByIdNotIn(paperIds));
+            return sortPapers(paperRepository.findByIdNotInAndConferencesIsNullAndStatusNot(paperIds, COMPLETED));
         } else {
-            return sortPapers(paperRepository.findAll());
+            return sortPapers(paperRepository.findByConferencesIsNullAndStatusNot(COMPLETED));
         }
     }