Package com.mongodb.gridfs

Class GridFS

java.lang.Object
com.mongodb.gridfs.GridFS
public class GridFS extends Object

Implementation of GridFS - a specification for storing and retrieving files that exceed the BSON-document size limit of 16MB.

Instead of storing a file in a single document, GridFS divides a file into parts, or chunks, and stores each of those chunks as a separate document. By default GridFS limits chunk size to 255k. GridFS uses two collections to store files. One collection stores the file chunks, and the other stores file metadata.

When you query a GridFS store for a file, the driver or client will reassemble the chunks as needed. You can perform range queries on files stored through GridFS. You also can access information from arbitrary sections of files, which allows you to "skip" into the middle of a video or audio file.

GridFS is useful not only for storing files that exceed 16MB but also for storing any files for which you want access without having to load the entire file into memory. For more information on the indications of GridFS, see MongoDB official documentation.

MongoDB documentation
GridFS

  • Field Details

    • DEFAULT_CHUNKSIZE

      public static final int DEFAULT_CHUNKSIZE
      File's chunk size
      See Also:

    • DEFAULT_BUCKET

      public static final String DEFAULT_BUCKET
      Bucket to use for the collection namespaces
      See Also:

  • Constructor Details

    • GridFS

      public GridFS(DB db)
      Creates a GridFS instance for the default bucket "fs" in the given database. Set the preferred WriteConcern on the give DB with DB.setWriteConcern
      Parameters:
      db - database to work with
      Throws:
      MongoException - if there's a failure
      See Also:

    • GridFS

      public GridFS(DB db, String bucket)
      Creates a GridFS instance for the specified bucket in the given database. Set the preferred WriteConcern on the give DB with DB.setWriteConcern
      Parameters:
      db - database to work with
      bucket - bucket to use in the given database
      Throws:
      MongoException - if there's a failure
      See Also:

  • Method Details

    • getFileList

      public DBCursor getFileList()
      Gets the list of files stored in this gridfs, sorted by filename.
      Returns:
      cursor of file objects

    • getFileList

      public DBCursor getFileList(DBObject query)
      Gets a filtered list of files stored in this gridfs, sorted by filename.
      Parameters:
      query - filter to apply
      Returns:
      cursor of file objects

    • getFileList

      public DBCursor getFileList(DBObject query, DBObject sort)
      Gets a sorted, filtered list of files stored in this gridfs.
      Parameters:
      query - filter to apply
      sort - sorting to apply
      Returns:
      cursor of file objects

    • find

      @Nullable public GridFSDBFile find(ObjectId objectId)
      Finds one file matching the given objectId. Equivalent to findOne(objectId).
      Parameters:
      objectId - the objectId of the file stored on a server
      Returns:
      a gridfs file
      Throws:
      MongoException - if the operation fails

    • findOne

      @Nullable public GridFSDBFile findOne(ObjectId objectId)
      Finds one file matching the given objectId.
      Parameters:
      objectId - the objectId of the file stored on a server
      Returns:
      a gridfs file
      Throws:
      MongoException - if the operation fails

    • findOne

      @Nullable public GridFSDBFile findOne(String filename)
      Finds one file matching the given filename.
      Parameters:
      filename - the name of the file stored on a server
      Returns:
      the gridfs db file
      Throws:
      MongoException - if the operation fails

    • findOne

      @Nullable public GridFSDBFile findOne(DBObject query)
      Finds one file matching the given query.
      Parameters:
      query - filter to apply
      Returns:
      a gridfs file
      Throws:
      MongoException - if the operation fails

    • find

      public List<GridFSDBFile> find(String filename)
      Finds a list of files matching the given filename.
      Parameters:
      filename - the filename to look for
      Returns:
      list of gridfs files
      Throws:
      MongoException - if the operation fails

    • find

      public List<GridFSDBFile> find(String filename, DBObject sort)
      Finds a list of files matching the given filename.
      Parameters:
      filename - the filename to look for
      sort - the fields to sort with
      Returns:
      list of gridfs files
      Throws:
      MongoException - if the operation fails

    • find

      public List<GridFSDBFile> find(DBObject query)
      Finds a list of files matching the given query.
      Parameters:
      query - the filter to apply
      Returns:
      list of gridfs files
      Throws:
      MongoException - if the operation fails

    • find

      public List<GridFSDBFile> find(DBObject query, @Nullable DBObject sort)
      Finds a list of files matching the given query.
      Parameters:
      query - the filter to apply
      sort - the fields to sort with
      Returns:
      list of gridfs files
      Throws:
      MongoException - if the operation fails

    • remove

      public void remove(ObjectId id)
      Removes the file matching the given id.
      Parameters:
      id - the id of the file to be removed
      Throws:
      MongoException - if the operation fails

    • remove

      public void remove(String filename)
      Removes all files matching the given filename.
      Parameters:
      filename - the name of the file to be removed
      Throws:
      MongoException - if the operation fails

    • remove

      public void remove(DBObject query)
      Removes all files matching the given query.
      Parameters:
      query - filter to apply
      Throws:
      MongoException - if the operation fails

    • createFile

      public GridFSInputFile createFile(byte[] data)
      Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
      Parameters:
      data - the file's data
      Returns:
      a gridfs input file

    • createFile

      public GridFSInputFile createFile(File file) throws IOException
      Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
      Parameters:
      file - the file object
      Returns:
      a GridFS input file
      Throws:
      IOException - if there are problems reading file

    • createFile

      public GridFSInputFile createFile(InputStream in)
      Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
      Parameters:
      in - an inputstream containing the file's data
      Returns:
      a gridfs input file

    • createFile

      public GridFSInputFile createFile(InputStream in, boolean closeStreamOnPersist)
      Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
      Parameters:
      in - an inputstream containing the file's data
      closeStreamOnPersist - indicate the passed in input stream should be closed once the data chunk persisted
      Returns:
      a gridfs input file

    • createFile

      public GridFSInputFile createFile(InputStream in, @Nullable String filename)
      Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
      Parameters:
      in - an inputstream containing the file's data
      filename - the file name as stored in the db
      Returns:
      a gridfs input file

    • createFile

      public GridFSInputFile createFile(InputStream in, @Nullable String filename, boolean closeStreamOnPersist)
      Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
      Parameters:
      in - an inputstream containing the file's data
      filename - the file name as stored in the db
      closeStreamOnPersist - indicate the passed in input stream should be closed once the data chunk persisted
      Returns:
      a gridfs input file

    • createFile

      public GridFSInputFile createFile(String filename)
      Creates a file entry.
      Parameters:
      filename - the file name as stored in the db
      Returns:
      a gridfs input file
      See Also:

    • createFile

      public GridFSInputFile createFile()
      This method creates an empty GridFSInputFile instance. On this instance an OutputStream can be obtained using the GridFSInputFile.getOutputStream() method. You can still call GridFSInputFile.setContentType(String) and GridFSInputFile.setFilename(String). The file will be completely written and closed after calling the OutputStream.close() method on the output stream.
      Returns:
      GridFS file handle instance.

    • getBucketName

      public String getBucketName()
      Gets the bucket name used in the collection's namespace. Default value is 'fs'.
      Returns:
      the name of the file bucket

    • getDB

      public DB getDB()
      Gets the database used.
      Returns:
      the database

    • getFilesCollection

      protected DBCollection getFilesCollection()
      Gets the DBCollection in which the file's metadata is stored.
      Returns:
      the collection

    • getChunksCollection

      protected DBCollection getChunksCollection()
      Gets the DBCollection in which the binary chunks are stored.
      Returns:
      the collection