DATAMONGO-2327 - Polishing.

Add support for DBRef encoding. Update Javadoc.

Original pull request: #774.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/QuerydslAbstractMongodbQuery.java

@@ -18,10 +18,13 @@ package org.springframework.data.mongodb.repository.support;
 import java.util.List;
 
 import org.bson.Document;
+import org.bson.codecs.DocumentCodec;
 import org.bson.json.JsonMode;
 import org.bson.json.JsonWriterSettings;
+
 import org.springframework.lang.Nullable;
 
+import com.mongodb.MongoClientSettings;
 import com.querydsl.core.DefaultQueryMetadata;
 import com.querydsl.core.QueryModifiers;
 import com.querydsl.core.SimpleQuery;
@@ -216,6 +219,9 @@ public abstract class QuerydslAbstractMongodbQuery<K, Q extends QuerydslAbstract
 	 * find({"lastname" : "Matthews"}).sort({"firstname" : 1}).skip(1).limit(5)
 	 * </pre>
 	 *
+	 * Note that encoding to {@link String} may fail when using data types that cannot be encoded or DBRef's without an
+	 * identifier.
+	 *
 	 * @return never {@literal null}.
 	 */
 	@Override
@@ -223,20 +229,21 @@ public abstract class QuerydslAbstractMongodbQuery<K, Q extends QuerydslAbstract
 
 		Document projection = createProjection(queryMixin.getMetadata().getProjection());
 		Document sort = createSort(queryMixin.getMetadata().getOrderBy());
+		DocumentCodec codec = new DocumentCodec(MongoClientSettings.getDefaultCodecRegistry());
 
-		StringBuilder sb = new StringBuilder("find(" + asDocument().toJson(JSON_WRITER_SETTINGS));
+		StringBuilder sb = new StringBuilder("find(" + asDocument().toJson(JSON_WRITER_SETTINGS, codec));
 		if (!projection.isEmpty()) {
-			sb.append(", " + projection.toJson(JSON_WRITER_SETTINGS));
+			sb.append(", ").append(projection.toJson(JSON_WRITER_SETTINGS, codec));
 		}
 		sb.append(")");
 		if (!sort.isEmpty()) {
-			sb.append(".sort(" + sort.toJson(JSON_WRITER_SETTINGS) + ")");
+			sb.append(".sort(").append(sort.toJson(JSON_WRITER_SETTINGS, codec)).append(")");
 		}
 		if (queryMixin.getMetadata().getModifiers().getOffset() != null) {
-			sb.append(".skip(" + queryMixin.getMetadata().getModifiers().getOffset() + ")");
+			sb.append(".skip(").append(queryMixin.getMetadata().getModifiers().getOffset()).append(")");
 		}
 		if (queryMixin.getMetadata().getModifiers().getLimit() != null) {
-			sb.append(".limit(" + queryMixin.getMetadata().getModifiers().getLimit() + ")");
+			sb.append(".limit(").append(queryMixin.getMetadata().getModifiers().getLimit()).append(")");
 		}
 		return sb.toString();
 	}

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/repository/support/QuerydslRepositorySupportTests.java

@@ -25,6 +25,7 @@ import org.bson.types.ObjectId;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+
 import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.annotation.Id;
@@ -262,17 +263,23 @@ public class QuerydslRepositorySupportTests {
 	public void toStringShouldRenderQuery() {
 
 		QPerson p = QPerson.person;
-		SpringDataMongodbQuery<Person> query = repoSupport.from(p).where(p.lastname.eq("Matthews"));
+		User user = new User();
+		user.setId("id");
+		SpringDataMongodbQuery<Person> query = repoSupport.from(p)
+				.where(p.lastname.eq("Matthews").and(p.coworker.eq(user)));
 
-		assertThat(StringUtils.trimAllWhitespace(query.toString())).isEqualTo("find({\"lastname\":\"Matthews\"})");
+		assertThat(StringUtils.trimAllWhitespace(query.toString()))
+				.isEqualTo("find({\"lastname\":\"Matthews\",\"coworker\":{\"$ref\":\"user\",\"$id\":\"id\"}})");
 
 		query = query.orderBy(p.firstname.asc());
 		assertThat(StringUtils.trimAllWhitespace(query.toString()))
-				.isEqualTo("find({\"lastname\":\"Matthews\"}).sort({\"firstname\":1})");
+				.isEqualTo(
+						"find({\"lastname\":\"Matthews\",\"coworker\":{\"$ref\":\"user\",\"$id\":\"id\"}}).sort({\"firstname\":1})");
 
 		query = query.offset(1).limit(5);
 		assertThat(StringUtils.trimAllWhitespace(query.toString()))
-				.isEqualTo("find({\"lastname\":\"Matthews\"}).sort({\"firstname\":1}).skip(1).limit(5)");
+				.isEqualTo(
+						"find({\"lastname\":\"Matthews\",\"coworker\":{\"$ref\":\"user\",\"$id\":\"id\"}}).sort({\"firstname\":1}).skip(1).limit(5)");
 	}
 
 	@Data