Merge pull request #20 from kaiso/support/feature/#14

[fix] do not override attribute when can not fetch child collection

Author: kaiso

src/main/java/io/github/kaiso/relmongo/events/callback/PersistentPropertyLazyLoadingCallback.java

@@ -71,7 +71,7 @@ public void doWith(Field field) throws IllegalAccessException {
 
             Object relations = document.get(joinPropertyName);
             List<Object> identifierList = new ArrayList<>();
-            if (relations == null) {
+            if (relations == null || ((DBObject)relations).keySet().isEmpty()) {
                 return;
             }
             if (relations instanceof Collection) {

src/main/java/io/github/kaiso/relmongo/events/callback/PersistentPropertyLoadingCallback.java

@@ -18,6 +18,7 @@
 
 import com.mongodb.BasicDBList;
 import com.mongodb.BasicDBObject;
+import com.mongodb.DBObject;
 
 import io.github.kaiso.relmongo.annotation.FetchType;
 import io.github.kaiso.relmongo.annotation.JoinProperty;
@@ -70,7 +71,7 @@ private void loadAssociation(Field field, FetchType fetchType, Class<?> annotati
 
             ids = ((BasicDBObject) source).get(name);
 
-            if (DocumentUtils.isLoaded(((BasicDBObject) source).get(field.getName())) || ids == null) {
+            if (DocumentUtils.isLoaded(((BasicDBObject) source).get(field.getName())) || ids == null || ((DBObject)ids).keySet().isEmpty()) {
                 return;
             }
 

src/main/java/io/github/kaiso/relmongo/lazy/RelMongoLazyLoader.java

@@ -28,14 +28,15 @@ public RelMongoLazyLoader(List<Object> ids, MongoOperations mongoOperations, Cla
 
     @Override
     public Object loadObject() throws Exception {
+        Object result = null;
         if (!(original instanceof LazyLoadingProxy) && !ids.isEmpty()) {
             if (Collection.class.isAssignableFrom(fieldType)) {
-                return DatabaseOperations.findByIds(mongoOperations, targetClass, ids.toArray(new ObjectId[ids.size()]));
+                result = DatabaseOperations.findByIds(mongoOperations, targetClass, ids.toArray(new ObjectId[ids.size()]));
             } else {
-                return DatabaseOperations.findByPropertyValue(mongoOperations, targetClass, "_id", ids.get(0));
+                result = DatabaseOperations.findByPropertyValue(mongoOperations, targetClass, "_id", ids.get(0));
             }
         }
-        return original;
+        return result != null ? result : original;
     }
 
 }

src/test/java/io/github/kaiso/relmongo/data/model/Person.java

@@ -9,75 +9,85 @@
 import org.bson.types.ObjectId;
 import org.springframework.data.mongodb.core.mapping.Document;
 
+import java.util.ArrayList;
 import java.util.List;
 
 @Document(collection = "people")
 public class Person {
     private ObjectId id;
     private String name;
     private String email;
-    
-    @OneToMany(fetch=FetchType.EAGER, cascade = CascadeType.ALL)
-    @JoinProperty(name="carsrefs")
+
+    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
+    @JoinProperty(name = "carsrefs")
     private List<Car> cars;
-    
-    @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.PERSIST)
-    @JoinProperty(name="housesrefs")
-    private List<House> houses;
-    
-    @OneToOne(fetch=FetchType.EAGER)
+
+    @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.PERSIST)
+    @JoinProperty(name = "housesrefs")
+    private List<House> houses = new ArrayList<>();
+
+    @OneToOne(fetch = FetchType.EAGER)
     @JoinProperty(name = "passportref")
     private Passport passport;
-    
-    @OneToOne(fetch=FetchType.LAZY, cascade = CascadeType.PERSIST)
+
+    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.PERSIST)
     @JoinProperty(name = "drivingLicenseref")
     private DrivingLicense drivingLicense;
-    
+
     public String getName() {
         return name;
     }
+
     public void setName(String name) {
         this.name = name;
     }
+
     public String getEmail() {
         return email;
     }
+
     public void setEmail(String email) {
         this.email = email;
     }
+
     public List<Car> getCars() {
         return cars;
     }
+
     public void setCars(List<Car> cars) {
         this.cars = cars;
     }
+
     public ObjectId getId() {
         return id;
     }
+
     public void setId(ObjectId id) {
         this.id = id;
     }
+
     public List<House> getHouses() {
         return houses;
     }
+
     public void setHouses(List<House> houses) {
         this.houses = houses;
     }
+
     public Passport getPassport() {
         return passport;
     }
+
     public void setPassport(Passport passport) {
         this.passport = passport;
     }
+
     public DrivingLicense getDrivingLicense() {
         return drivingLicense;
     }
+
     public void setDrivingLicense(DrivingLicense drivingLicense) {
         this.drivingLicense = drivingLicense;
     }
-    
-    
 
-    
-    
 }