Package com.google.cloud.firestore

Class CollectionReference

java.lang.Object

com.google.cloud.firestore.StreamableQuery<QuerySnapshot>

com.google.cloud.firestore.Query

com.google.cloud.firestore.CollectionReference

@InternalExtensionOnly
public class CollectionReference
extends Query

A CollectionReference can be used for adding documents, getting document references, and querying for documents (using the methods inherited from Query).

Subclassing Note: Firestore classes are not meant to be subclassed except for use in test mocks. Subclassing is not supported in production code and new SDK releases may break code that does so.

Nested Class Summary

Nested classes/interfaces inherited from class com.google.cloud.firestore.Query

Query.Direction

Method Summary

Modifier and Type	Method	Description
com.google.api.core.ApiFuture<DocumentReference>	add(Object pojo)	Adds a new document to this collection with the specified POJO as contents, assigning it a document ID automatically.
com.google.api.core.ApiFuture<DocumentReference>	add(Map<String,Object> fields)	Adds a new document to this collection with the specified data, assigning it a document ID automatically.
DocumentReference	document()	Returns a DocumentReference pointing to a new document with an auto-generated ID within this collection.
DocumentReference	document(String childPath)	Gets a DocumentReference instance that refers to the document that is a child of this Collection.
String	getId()	The id of a collection refers to the last component of path pointing to a collection, for example "collection-id" in "projects/project-id/databases/database-id/documents/collection-id".
DocumentReference	getParent()	Returns a DocumentReference to the containing Document if this is a subcollection, else null.
String	getPath()	A string representing the path of the referenced collection (relative to the root of the database).
Iterable<DocumentReference>	listDocuments()	Retrieves the list of documents in this collection.

Methods inherited from class com.google.cloud.firestore.Query

addSnapshotListener, addSnapshotListener, aggregate, count, endAt, endAt, endBefore, endBefore, equals, explain, explainStream, findNearest, findNearest, findNearest, findNearest, fromProto, get, hashCode, limit, limitToLast, offset, orderBy, orderBy, orderBy, orderBy, select, select, startAfter, startAfter, startAt, startAt, stream, toProto, toRunQueryRequestBuilder, where, whereArrayContains, whereArrayContains, whereArrayContainsAny, whereArrayContainsAny, whereEqualTo, whereEqualTo, whereGreaterThan, whereGreaterThan, whereGreaterThanOrEqualTo, whereGreaterThanOrEqualTo, whereIn, whereIn, whereLessThan, whereLessThan, whereLessThanOrEqualTo, whereLessThanOrEqualTo, whereNotEqualTo, whereNotEqualTo, whereNotIn, whereNotIn

Methods inherited from class com.google.cloud.firestore.StreamableQuery

getFirestore, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Details

getId

@Nonnull
public String getId()

The id of a collection refers to the last component of path pointing to a collection, for example "collection-id" in "projects/project-id/databases/database-id/documents/collection-id".

Returns:

The ID of the collection.

getParent

@Nullable
public DocumentReference getParent()

Returns a DocumentReference to the containing Document if this is a subcollection, else null.

Returns:

A DocumentReference pointing to the parent document.

getPath

@Nonnull
public String getPath()

A string representing the path of the referenced collection (relative to the root of the database).

Returns:

The slash-separated path relative to the root of the database.

document

@Nonnull
public DocumentReference document()

Returns a DocumentReference pointing to a new document with an auto-generated ID within this collection.

Returns:

A DocumentReference pointing to a new document with an auto-generated ID.

document

@Nonnull
public DocumentReference document(@Nonnull
 String childPath)

Gets a DocumentReference instance that refers to the document that is a child of this Collection.

Parameters:

childPath - A relative and slash-separated path to a document.

Returns:

The DocumentReference instance.

listDocuments

@Nonnull
public Iterable<DocumentReference> listDocuments()

Retrieves the list of documents in this collection.

The document references returned may include references to "missing documents", specifically document locations that have no document present but which contain subcollections with documents. Attempting to read such a document reference (for example via `get()` or `onSnapshot()`) will return a `DocumentSnapshot` whose `exists()` method returns false.

Returns:

The list of documents in this collection.

add

@Nonnull
public com.google.api.core.ApiFuture<DocumentReference> add(@Nonnull
 Map<String,Object> fields)

Adds a new document to this collection with the specified data, assigning it a document ID automatically.

Parameters:

fields - A Map containing the data for the new document.

Returns:

An ApiFuture that will be resolved with the DocumentReference of the newly created document.

See Also:

• document()

add

public com.google.api.core.ApiFuture<DocumentReference> add(Object pojo)

Adds a new document to this collection with the specified POJO as contents, assigning it a document ID automatically.

Parameters:

pojo - The POJO that will be used to populate the contents of the document

Returns:

An ApiFuture that will be resolved with the DocumentReference of the newly created document.

See Also:

• document()