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The Java operations layer for the MongoDB Java Driver. Third parties can ' +
'wrap this layer to provide custom higher-level APIs
/*
* Copyright 2008-present MongoDB, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.mongodb;
import com.mongodb.lang.Nullable;
import org.bson.BSONObject;
import org.bson.BsonBinary;
import org.bson.BsonBinarySubType;
import org.bson.BsonDbPointer;
import org.bson.BsonDocument;
import org.bson.BsonDocumentWriter;
import org.bson.BsonReader;
import org.bson.BsonType;
import org.bson.BsonValue;
import org.bson.BsonWriter;
import org.bson.UuidRepresentation;
import org.bson.codecs.BsonTypeClassMap;
import org.bson.codecs.BsonTypeCodecMap;
import org.bson.codecs.BsonValueCodecProvider;
import org.bson.codecs.Codec;
import org.bson.codecs.CollectibleCodec;
import org.bson.codecs.DecoderContext;
import org.bson.codecs.EncoderContext;
import org.bson.codecs.IdGenerator;
import org.bson.codecs.ObjectIdGenerator;
import org.bson.codecs.OverridableUuidRepresentationCodec;
import org.bson.codecs.ValueCodecProvider;
import org.bson.codecs.configuration.CodecRegistry;
import org.bson.types.BSONTimestamp;
import org.bson.types.Binary;
import org.bson.types.CodeWScope;
import org.bson.types.Symbol;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.regex.Pattern;
import static com.mongodb.assertions.Assertions.notNull;
import static java.util.Arrays.asList;
import static org.bson.BsonBinarySubType.BINARY;
import static org.bson.BsonBinarySubType.OLD_BINARY;
import static org.bson.codecs.configuration.CodecRegistries.fromProviders;
/**
* A collectible codec for a DBObject.
*
* @since 3.0
*/
@SuppressWarnings({"rawtypes"})
public class DBObjectCodec implements CollectibleCodec, OverridableUuidRepresentationCodec {
private static final BsonTypeClassMap DEFAULT_BSON_TYPE_CLASS_MAP = createDefaultBsonTypeClassMap();
private static final CodecRegistry DEFAULT_REGISTRY =
fromProviders(asList(new ValueCodecProvider(), new BsonValueCodecProvider(), new DBObjectCodecProvider()));
private static final String ID_FIELD_NAME = "_id";
private final CodecRegistry codecRegistry;
private final BsonTypeCodecMap bsonTypeCodecMap;
private final DBObjectFactory objectFactory;
private final IdGenerator idGenerator = new ObjectIdGenerator();
private final UuidRepresentation uuidRepresentation;
private static BsonTypeClassMap createDefaultBsonTypeClassMap() {
Map> replacements = new HashMap<>();
replacements.put(BsonType.REGULAR_EXPRESSION, Pattern.class);
replacements.put(BsonType.SYMBOL, String.class);
replacements.put(BsonType.TIMESTAMP, BSONTimestamp.class);
replacements.put(BsonType.JAVASCRIPT_WITH_SCOPE, null);
replacements.put(BsonType.DOCUMENT, null);
return new BsonTypeClassMap(replacements);
}
static BsonTypeClassMap getDefaultBsonTypeClassMap() {
return DEFAULT_BSON_TYPE_CLASS_MAP;
}
static CodecRegistry getDefaultRegistry() {
return DEFAULT_REGISTRY;
}
/**
* Construct an instance with the default codec registry
*
* @since 3.7
*/
public DBObjectCodec() {
this(DEFAULT_REGISTRY);
}
/**
* Construct an instance with the given codec registry.
*
* @param codecRegistry the non-null codec registry
*/
public DBObjectCodec(final CodecRegistry codecRegistry) {
this(codecRegistry, DEFAULT_BSON_TYPE_CLASS_MAP);
}
/**
* Construct an instance.
*
* @param codecRegistry the codec registry
* @param bsonTypeClassMap the non-null BsonTypeClassMap
*/
public DBObjectCodec(final CodecRegistry codecRegistry, final BsonTypeClassMap bsonTypeClassMap) {
this(codecRegistry, bsonTypeClassMap, new BasicDBObjectFactory());
}
/**
* Construct an instance.
*
* @param codecRegistry the non-null codec registry
* @param bsonTypeClassMap the non-null BsonTypeClassMap
* @param objectFactory the non-null object factory used to create empty DBObject instances when decoding
*/
public DBObjectCodec(final CodecRegistry codecRegistry, final BsonTypeClassMap bsonTypeClassMap, final DBObjectFactory objectFactory) {
this(codecRegistry, new BsonTypeCodecMap(notNull("bsonTypeClassMap", bsonTypeClassMap), codecRegistry), objectFactory,
UuidRepresentation.UNSPECIFIED);
}
private DBObjectCodec(final CodecRegistry codecRegistry, final BsonTypeCodecMap bsonTypeCodecMap, final DBObjectFactory objectFactory,
final UuidRepresentation uuidRepresentation) {
this.objectFactory = notNull("objectFactory", objectFactory);
this.codecRegistry = notNull("codecRegistry", codecRegistry);
this.uuidRepresentation = notNull("uuidRepresentation", uuidRepresentation);
this.bsonTypeCodecMap = bsonTypeCodecMap;
}
@Override
public void encode(final BsonWriter writer, final DBObject document, final EncoderContext encoderContext) {
writer.writeStartDocument();
beforeFields(writer, encoderContext, document);
for (final String key : document.keySet()) {
if (skipField(encoderContext, key)) {
continue;
}
writer.writeName(key);
writeValue(writer, encoderContext, document.get(key));
}
writer.writeEndDocument();
}
@Override
public DBObject decode(final BsonReader reader, final DecoderContext decoderContext) {
List path = new ArrayList<>(10);
return readDocument(reader, decoderContext, path);
}
@Override
public Class getEncoderClass() {
return DBObject.class;
}
@Override
public boolean documentHasId(final DBObject document) {
return document.containsField(ID_FIELD_NAME);
}
@Override
public BsonValue getDocumentId(final DBObject document) {
if (!documentHasId(document)) {
throw new IllegalStateException("The document does not contain an _id");
}
Object id = document.get(ID_FIELD_NAME);
if (id instanceof BsonValue) {
return (BsonValue) id;
}
BsonDocument idHoldingDocument = new BsonDocument();
BsonWriter writer = new BsonDocumentWriter(idHoldingDocument);
writer.writeStartDocument();
writer.writeName(ID_FIELD_NAME);
writeValue(writer, EncoderContext.builder().build(), id);
writer.writeEndDocument();
return idHoldingDocument.get(ID_FIELD_NAME);
}
@Override
public DBObject generateIdIfAbsentFromDocument(final DBObject document) {
if (!documentHasId(document)) {
document.put(ID_FIELD_NAME, idGenerator.generate());
}
return document;
}
@Override
public Codec withUuidRepresentation(final UuidRepresentation uuidRepresentation) {
if (this.uuidRepresentation.equals(uuidRepresentation)) {
return this;
}
return new DBObjectCodec(codecRegistry, bsonTypeCodecMap, objectFactory, uuidRepresentation);
}
private void beforeFields(final BsonWriter bsonWriter, final EncoderContext encoderContext, final DBObject document) {
if (encoderContext.isEncodingCollectibleDocument() && document.containsField(ID_FIELD_NAME)) {
bsonWriter.writeName(ID_FIELD_NAME);
writeValue(bsonWriter, encoderContext, document.get(ID_FIELD_NAME));
}
}
private boolean skipField(final EncoderContext encoderContext, final String key) {
return encoderContext.isEncodingCollectibleDocument() && key.equals(ID_FIELD_NAME);
}
@SuppressWarnings("unchecked")
private void writeValue(final BsonWriter bsonWriter, final EncoderContext encoderContext, @Nullable final Object value) {
if (value == null) {
bsonWriter.writeNull();
} else if (value instanceof DBRef) {
encodeDBRef(bsonWriter, (DBRef) value, encoderContext);
} else if (value instanceof Map) {
encodeMap(bsonWriter, (Map) value, encoderContext);
} else if (value instanceof Iterable) {
encodeIterable(bsonWriter, (Iterable) value, encoderContext);
} else if (value instanceof BSONObject) {
encodeBsonObject(bsonWriter, (BSONObject) value, encoderContext);
} else if (value instanceof CodeWScope) {
encodeCodeWScope(bsonWriter, (CodeWScope) value, encoderContext);
} else if (value instanceof byte[]) {
encodeByteArray(bsonWriter, (byte[]) value);
} else if (value.getClass().isArray()) {
encodeArray(bsonWriter, value, encoderContext);
} else if (value instanceof Symbol) {
bsonWriter.writeSymbol(((Symbol) value).getSymbol());
} else {
Codec codec = codecRegistry.get(value.getClass());
encoderContext.encodeWithChildContext(codec, bsonWriter, value);
}
}
private void encodeMap(final BsonWriter bsonWriter, final Map document, final EncoderContext encoderContext) {
bsonWriter.writeStartDocument();
for (final Map.Entry entry : document.entrySet()) {
bsonWriter.writeName(entry.getKey());
writeValue(bsonWriter, encoderContext.getChildContext(), entry.getValue());
}
bsonWriter.writeEndDocument();
}
private void encodeBsonObject(final BsonWriter bsonWriter, final BSONObject document, final EncoderContext encoderContext) {
bsonWriter.writeStartDocument();
for (String key : document.keySet()) {
bsonWriter.writeName(key);
writeValue(bsonWriter, encoderContext.getChildContext(), document.get(key));
}
bsonWriter.writeEndDocument();
}
private void encodeByteArray(final BsonWriter bsonWriter, final byte[] value) {
bsonWriter.writeBinaryData(new BsonBinary(value));
}
private void encodeArray(final BsonWriter bsonWriter, final Object value, final EncoderContext encoderContext) {
bsonWriter.writeStartArray();
int size = Array.getLength(value);
for (int i = 0; i < size; i++) {
writeValue(bsonWriter, encoderContext.getChildContext(), Array.get(value, i));
}
bsonWriter.writeEndArray();
}
private void encodeDBRef(final BsonWriter bsonWriter, final DBRef dbRef, final EncoderContext encoderContext) {
bsonWriter.writeStartDocument();
bsonWriter.writeString("$ref", dbRef.getCollectionName());
bsonWriter.writeName("$id");
writeValue(bsonWriter, encoderContext.getChildContext(), dbRef.getId());
if (dbRef.getDatabaseName() != null) {
bsonWriter.writeString("$db", dbRef.getDatabaseName());
}
bsonWriter.writeEndDocument();
}
private void encodeCodeWScope(final BsonWriter bsonWriter, final CodeWScope value, final EncoderContext encoderContext) {
bsonWriter.writeJavaScriptWithScope(value.getCode());
encodeBsonObject(bsonWriter, value.getScope(), encoderContext.getChildContext());
}
private void encodeIterable(final BsonWriter bsonWriter, final Iterable iterable, final EncoderContext encoderContext) {
bsonWriter.writeStartArray();
for (final Object cur : iterable) {
writeValue(bsonWriter, encoderContext.getChildContext(), cur);
}
bsonWriter.writeEndArray();
}
@Nullable private Object readValue(final BsonReader reader, final DecoderContext decoderContext, @Nullable final String fieldName,
final List path) {
Object initialRetVal;
BsonType bsonType = reader.getCurrentBsonType();
if (bsonType.isContainer() && fieldName != null) {
//if we got into some new context like nested document or array
path.add(fieldName);
}
switch (bsonType) {
case DOCUMENT:
initialRetVal = verifyForDBRef(readDocument(reader, decoderContext, path));
break;
case ARRAY:
initialRetVal = readArray(reader, decoderContext, path);
break;
case JAVASCRIPT_WITH_SCOPE: //custom for driver-compat types
initialRetVal = readCodeWScope(reader, decoderContext, path);
break;
case DB_POINTER: //custom for driver-compat types
BsonDbPointer dbPointer = reader.readDBPointer();
initialRetVal = new DBRef(dbPointer.getNamespace(), dbPointer.getId());
break;
case BINARY:
initialRetVal = readBinary(reader, decoderContext);
break;
case NULL:
reader.readNull();
initialRetVal = null;
break;
default:
initialRetVal = bsonTypeCodecMap.get(bsonType).decode(reader, decoderContext);
}
if (bsonType.isContainer() && fieldName != null) {
//step out of current context to a parent
path.remove(fieldName);
}
return initialRetVal;
}
private Object readBinary(final BsonReader reader, final DecoderContext decoderContext) {
byte bsonBinarySubType = reader.peekBinarySubType();
Codec codec;
if (BsonBinarySubType.isUuid(bsonBinarySubType) && reader.peekBinarySize() == 16) {
codec = codecRegistry.get(Binary.class);
switch (bsonBinarySubType) {
case 3:
if (uuidRepresentation == UuidRepresentation.JAVA_LEGACY
|| uuidRepresentation == UuidRepresentation.C_SHARP_LEGACY
|| uuidRepresentation == UuidRepresentation.PYTHON_LEGACY) {
codec = codecRegistry.get(UUID.class);
}
break;
case 4:
if (uuidRepresentation == UuidRepresentation.STANDARD) {
codec = codecRegistry.get(UUID.class);
}
break;
default:
throw new UnsupportedOperationException("Unknown UUID binary subtype " + bsonBinarySubType);
}
} else if (bsonBinarySubType == BINARY.getValue() || bsonBinarySubType == OLD_BINARY.getValue()) {
codec = codecRegistry.get(byte[].class);
} else {
codec = codecRegistry.get(Binary.class);
}
return codec.decode(reader, decoderContext);
}
private List readArray(final BsonReader reader, final DecoderContext decoderContext, final List path) {
reader.readStartArray();
BasicDBList list = new BasicDBList();
while (reader.readBsonType() != BsonType.END_OF_DOCUMENT) {
list.add(readValue(reader, decoderContext, null, path));
}
reader.readEndArray();
return list;
}
private DBObject readDocument(final BsonReader reader, final DecoderContext decoderContext, final List path) {
DBObject document = objectFactory.getInstance(path);
reader.readStartDocument();
while (reader.readBsonType() != BsonType.END_OF_DOCUMENT) {
String fieldName = reader.readName();
document.put(fieldName, readValue(reader, decoderContext, fieldName, path));
}
reader.readEndDocument();
return document;
}
private CodeWScope readCodeWScope(final BsonReader reader, final DecoderContext decoderContext, final List path) {
return new CodeWScope(reader.readJavaScriptWithScope(), readDocument(reader, decoderContext, path));
}
private Object verifyForDBRef(final DBObject document) {
if (document.containsField("$ref") && document.containsField("$id")) {
return new DBRef((String) document.get("$db"), (String) document.get("$ref"), document.get("$id"));
} else {
return document;
}
}
}