DATAMONGO-2388 - Fix CodecConfigurationException when reading index info that contains DbRef.

Provide the default CodecRegistry when converting partial index data to its String representation used in IndexInfo.

Original pull request: #797.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/IndexInfo.java

@@ -25,6 +25,7 @@ import java.util.List;
 import java.util.Optional;
 
 import org.bson.Document;
+import org.springframework.data.mongodb.util.BsonUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
@@ -107,8 +108,8 @@ public class IndexInfo {
 		boolean sparse = sourceDocument.containsKey("sparse") ? (Boolean) sourceDocument.get("sparse") : false;
 		String language = sourceDocument.containsKey("default_language") ? (String) sourceDocument.get("default_language")
 				: "";
-		String partialFilter = sourceDocument.containsKey("partialFilterExpression")
-				? ((Document) sourceDocument.get("partialFilterExpression")).toJson() : null;
+
+		String partialFilter = extractPartialFilterString(sourceDocument);
 
 		IndexInfo info = new IndexInfo(indexFields, name, unique, sparse, language);
 		info.partialFilterExpression = partialFilter;
@@ -116,6 +117,21 @@ public class IndexInfo {
 		return info;
 	}
 
+	/**
+	 * @param sourceDocument
+	 * @return the {@link String} representation of the partial filter {@link Document}.
+	 * @since 2.1.11
+	 */
+	@Nullable
+	private static String extractPartialFilterString(Document sourceDocument) {
+
+		if (!sourceDocument.containsKey("partialFilterExpression")) {
+			return null;
+		}
+
+		return BsonUtils.toJson(sourceDocument.get("partialFilterExpression", Document.class));
+	}
+
 	/**
 	 * Returns the individual index fields of the index.
 	 *

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/util/BsonUtils.java

@@ -15,17 +15,27 @@
  */
 package org.springframework.data.mongodb.util;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Date;
 import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
 
 import org.bson.BsonValue;
 import org.bson.Document;
 import org.bson.conversions.Bson;
+import org.bson.json.JsonParseException;
+
+import org.springframework.core.convert.converter.Converter;
 import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
 
 import com.mongodb.BasicDBObject;
 import com.mongodb.DBObject;
 import com.mongodb.DBRef;
+import com.mongodb.MongoClientSettings;
 
 /**
  * @author Christoph Strobl
@@ -104,4 +114,79 @@ public class BsonUtils {
 				return value;
 		}
 	}
+
+	/**
+	 * Serialize the given {@link Document} as Json applying default codecs if necessary.
+	 *
+	 * @param source
+	 * @return
+	 * @since 2.1.1
+	 */
+	@Nullable
+	public static String toJson(@Nullable Document source) {
+
+		if (source == null) {
+			return null;
+		}
+
+		try {
+			return source.toJson();
+		} catch (Exception e) {
+			return toJson((Object) source);
+		}
+	}
+
+	private static String toJson(@Nullable Object value) {
+
+		if (value == null) {
+			return null;
+		}
+
+		try {
+			return value instanceof Document
+					? ((Document) value).toJson(MongoClientSettings.getDefaultCodecRegistry().get(Document.class))
+					: serializeValue(value);
+
+		} catch (Exception e) {
+
+			if (value instanceof Collection) {
+				return toString((Collection<?>) value);
+			} else if (value instanceof Map) {
+				return toString((Map<?, ?>) value);
+			} else if (ObjectUtils.isArray(value)) {
+				return toString(Arrays.asList(ObjectUtils.toObjectArray(value)));
+			}
+
+			throw e instanceof JsonParseException ? (JsonParseException) e : new JsonParseException(e);
+		}
+	}
+
+	private static String serializeValue(@Nullable Object value) {
+
+		if (value == null) {
+			return "null";
+		}
+
+		String documentJson = new Document("toBeEncoded", value).toJson();
+		return documentJson.substring(documentJson.indexOf(':') + 1, documentJson.length() - 1).trim();
+	}
+
+	private static String toString(Map<?, ?> source) {
+
+		return iterableToDelimitedString(source.entrySet(), "{ ", " }",
+				entry -> String.format("\"%s\" : %s", entry.getKey(), toJson(entry.getValue())));
+	}
+
+	private static String toString(Collection<?> source) {
+		return iterableToDelimitedString(source, "[ ", " ]", BsonUtils::toJson);
+	}
+
+	private static <T> String iterableToDelimitedString(Iterable<T> source, String prefix, String postfix,
+			Converter<? super T, Object> transformer) {
+
+		return prefix
+				+ StringUtils.collectionToCommaDelimitedString(
+						StreamSupport.stream(source.spliterator(), false).map(transformer::convert).collect(Collectors.toList()))
+				+ postfix;
+	}
 }

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/DefaultIndexOperationsIntegrationTests.java

@@ -21,6 +21,7 @@ import static org.junit.Assume.*;
 import static org.springframework.data.mongodb.core.index.PartialIndexFilter.*;
 import static org.springframework.data.mongodb.core.query.Criteria.*;
 
+import org.bson.BsonDocument;
 import org.bson.Document;
 import org.junit.Before;
 import org.junit.Test;
@@ -40,6 +41,7 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import org.springframework.util.ObjectUtils;
 
 import com.mongodb.client.MongoCollection;
+import com.mongodb.client.model.IndexOptions;
 
 /**
  * Integration tests for {@link DefaultIndexOperations}.
@@ -150,6 +152,21 @@ public class DefaultIndexOperationsIntegrationTests {
 		assertThat(info.getPartialFilterExpression()).isEqualTo("{ \"a_g_e\" : { \"$gte\" : 10 } }");
 	}
 
+	@Test // DATAMONGO-2388
+	public void shouldReadIndexWithPartialFilterContainingDbRefCorrectly() {
+
+		BsonDocument partialFilter = BsonDocument.parse(
+				"{ \"the-ref\" : { \"$ref\" : \"other-collection\", \"$id\" : { \"$oid\" : \"59ce08baf264b906810fe8c5\"} } }");
+		IndexOptions indexOptions = new IndexOptions();
+		indexOptions.name("partial-with-dbref");
+		indexOptions.partialFilterExpression(partialFilter);
+
+		collection.createIndex(BsonDocument.parse("{ \"key-1\" : 1, \"key-2\": 1}"), indexOptions);
+
+		IndexInfo info = findAndReturnIndexInfo(indexOps.getIndexInfo(), "partial-with-dbref");
+		assertThat(BsonDocument.parse(info.getPartialFilterExpression())).isEqualTo(partialFilter);
+	}
+
 	@Test // DATAMONGO-1518
 	public void shouldCreateIndexWithCollationCorrectly() {