GridFS (mongo-java-driver 3.3.0-query-log-max-size API)

java.lang.Object
- com.mongodb.gridfs.GridFS

```
public class GridFS
extends java.lang.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

字段概要

字段
限定符和类型	字段和说明
`static java.lang.String`	`DEFAULT_BUCKET` Bucket to use for the collection namespaces
`static int`	`DEFAULT_CHUNKSIZE` File's chunk size
`static long`	`MAX_CHUNKSIZE` 已过时。 You can calculate max chunkSize with a similar formula `Mongo.getMaxBsonObjectSize()` - 500*1000. Please ensure that you left enough space for metadata (500kb is enough).

构造器概要

构造器
构造器和说明
`GridFS(DB db)` Creates a GridFS instance for the default bucket "fs" in the given database.
`GridFS(DB db, java.lang.String bucket)` Creates a GridFS instance for the specified bucket in the given database.

方法概要

所有方法实例方法具体方法
限定符和类型	方法和说明
`GridFSInputFile`	`createFile()` This method creates an empty `GridFSInputFile` instance.
`GridFSInputFile`	`createFile(byte[] data)` Creates a file entry.
`GridFSInputFile`	`createFile(java.io.File file)` Creates a file entry.
`GridFSInputFile`	`createFile(java.io.InputStream in)` Creates a file entry.
`GridFSInputFile`	`createFile(java.io.InputStream in, boolean closeStreamOnPersist)` Creates a file entry.
`GridFSInputFile`	`createFile(java.io.InputStream in, java.lang.String filename)` Creates a file entry.
`GridFSInputFile`	`createFile(java.io.InputStream in, java.lang.String filename, boolean closeStreamOnPersist)` Creates a file entry.
`GridFSInputFile`	`createFile(java.lang.String filename)` Creates a file entry.
`java.util.List<GridFSDBFile>`	`find(DBObject query)` Finds a list of files matching the given query.
`java.util.List<GridFSDBFile>`	`find(DBObject query, DBObject sort)` Finds a list of files matching the given query.
`GridFSDBFile`	`find(ObjectId objectId)` Finds one file matching the given objectId.
`java.util.List<GridFSDBFile>`	`find(java.lang.String filename)` Finds a list of files matching the given filename.
`java.util.List<GridFSDBFile>`	`find(java.lang.String filename, DBObject sort)` Finds a list of files matching the given filename.
`GridFSDBFile`	`findOne(DBObject query)` Finds one file matching the given query.
`GridFSDBFile`	`findOne(ObjectId objectId)` Finds one file matching the given objectId.
`GridFSDBFile`	`findOne(java.lang.String filename)` Finds one file matching the given filename.
`java.lang.String`	`getBucketName()` Gets the bucket name used in the collection's namespace.
`protected DBCollection`	`getChunksCollection()` Gets the `DBCollection` in which the binary chunks are stored.
`DB`	`getDB()` Gets the database used.
`DBCursor`	`getFileList()` Gets the list of files stored in this gridfs, sorted by filename.
`DBCursor`	`getFileList(DBObject query)` Gets a filtered list of files stored in this gridfs, sorted by filename.
`DBCursor`	`getFileList(DBObject query, DBObject sort)` Gets a sorted, filtered list of files stored in this gridfs.
`protected DBCollection`	`getFilesCollection()` Gets the `DBCollection` in which the file's metadata is stored.
`void`	`remove(DBObject query)` Removes all files matching the given query.
`void`	`remove(ObjectId id)` Removes the file matching the given id.
`void`	`remove(java.lang.String filename)` Removes all files matching the given filename.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - DEFAULT_CHUNKSIZE
```
public static final int DEFAULT_CHUNKSIZE
```
    File's chunk size
    
    另请参阅:
    
    常量字段值
  - MAX_CHUNKSIZE
```
@Deprecated
public static final long MAX_CHUNKSIZE
```
    已过时。 You can calculate max chunkSize with a similar formula Mongo.getMaxBsonObjectSize() - 500*1000. Please ensure that you left enough space for metadata (500kb is enough).
    
    File's max chunk size
    
    另请参阅:
    
    常量字段值
  - DEFAULT_BUCKET
```
public static final java.lang.String DEFAULT_BUCKET
```
    Bucket to use for the collection namespaces
    
    另请参阅:
    
    常量字段值
- 构造器详细资料
  - 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
    
    参数:
    
    db - database to work with
    
    抛出:
    
    MongoException - if there's a failure
    
    另请参阅:
    
    WriteConcern
  - GridFS
```
public GridFS(DB db,
              java.lang.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
    
    参数:
    
    db - database to work with
    
    bucket - bucket to use in the given database
    
    抛出:
    
    MongoException - if there's a failure
    
    另请参阅:
    
    WriteConcern
- 方法详细资料
  - getFileList
```
public DBCursor getFileList()
```
    Gets the list of files stored in this gridfs, sorted by filename.
    
    返回:
    
    cursor of file objects
  - getFileList
```
public DBCursor getFileList(DBObject query)
```
    Gets a filtered list of files stored in this gridfs, sorted by filename.
    
    参数:
    
    query - filter to apply
    
    返回:
    
    cursor of file objects
  - getFileList
```
public DBCursor getFileList(DBObject query,
                            DBObject sort)
```
    Gets a sorted, filtered list of files stored in this gridfs.
    
    参数:
    
    query - filter to apply
    
    sort - sorting to apply
    
    返回:
    
    cursor of file objects
  - find
```
public GridFSDBFile find(ObjectId objectId)
```
    Finds one file matching the given objectId. Equivalent to findOne(objectId).
    
    参数:
    
    objectId - the objectId of the file stored on a server
    
    返回:
    
    a gridfs file
    
    抛出:
    
    MongoException - if the operation fails
  - findOne
```
public GridFSDBFile findOne(ObjectId objectId)
```
    Finds one file matching the given objectId.
    
    参数:
    
    objectId - the objectId of the file stored on a server
    
    返回:
    
    a gridfs file
    
    抛出:
    
    MongoException - if the operation fails
  - findOne
```
public GridFSDBFile findOne(java.lang.String filename)
```
    Finds one file matching the given filename.
    
    参数:
    
    filename - the name of the file stored on a server
    
    返回:
    
    the gridfs db file
    
    抛出:
    
    MongoException - if the operation fails
  - findOne
```
public GridFSDBFile findOne(DBObject query)
```
    Finds one file matching the given query.
    
    参数:
    
    query - filter to apply
    
    返回:
    
    a gridfs file
    
    抛出:
    
    MongoException - if the operation fails
  - find
```
public java.util.List<GridFSDBFile> find(java.lang.String filename)
```
    Finds a list of files matching the given filename.
    
    参数:
    
    filename - the filename to look for
    
    返回:
    
    list of gridfs files
    
    抛出:
    
    MongoException - if the operation fails
  - find
```
public java.util.List<GridFSDBFile> find(java.lang.String filename,
                                         DBObject sort)
```
    Finds a list of files matching the given filename.
    
    参数:
    
    filename - the filename to look for
    
    sort - the fields to sort with
    
    返回:
    
    list of gridfs files
    
    抛出:
    
    MongoException - if the operation fails
  - find
```
public java.util.List<GridFSDBFile> find(DBObject query)
```
    Finds a list of files matching the given query.
    
    参数:
    
    query - the filter to apply
    
    返回:
    
    list of gridfs files
    
    抛出:
    
    MongoException - if the operation fails
  - find
```
public java.util.List<GridFSDBFile> find(DBObject query,
                                         DBObject sort)
```
    Finds a list of files matching the given query.
    
    参数:
    
    query - the filter to apply
    
    sort - the fields to sort with
    
    返回:
    
    list of gridfs files
    
    抛出:
    
    MongoException - if the operation fails
  - remove
```
public void remove(ObjectId id)
```
    Removes the file matching the given id.
    
    参数:
    
    id - the id of the file to be removed
    
    抛出:
    
    MongoException - if the operation fails
  - remove
```
public void remove(java.lang.String filename)
```
    Removes all files matching the given filename.
    
    参数:
    
    filename - the name of the file to be removed
    
    抛出:
    
    MongoException - if the operation fails
  - remove
```
public void remove(DBObject query)
```
    Removes all files matching the given query.
    
    参数:
    
    query - filter to apply
    
    抛出:
    
    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().
    
    参数:
    
    data - the file's data
    
    返回:
    
    a gridfs input file
  - createFile
```
public GridFSInputFile createFile(java.io.File file)
                           throws java.io.IOException
```
    Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
    
    参数:
    
    file - the file object
    
    返回:
    
    a GridFS input file
    
    抛出:
    
    java.io.IOException - if there are problems reading file
  - createFile
```
public GridFSInputFile createFile(java.io.InputStream in)
```
    Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
    
    参数:
    
    in - an inputstream containing the file's data
    
    返回:
    
    a gridfs input file
  - createFile
```
public GridFSInputFile createFile(java.io.InputStream in,
                                  boolean closeStreamOnPersist)
```
    Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
    
    参数:
    
    in - an inputstream containing the file's data
    
    closeStreamOnPersist - indicate the passed in input stream should be closed once the data chunk persisted
    
    返回:
    
    a gridfs input file
  - createFile
```
public GridFSInputFile createFile(java.io.InputStream in,
                                  java.lang.String filename)
```
    Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
    
    参数:
    
    in - an inputstream containing the file's data
    
    filename - the file name as stored in the db
    
    返回:
    
    a gridfs input file
  - createFile
```
public GridFSInputFile createFile(java.io.InputStream in,
                                  java.lang.String filename,
                                  boolean closeStreamOnPersist)
```
    Creates a file entry. After calling this method, you have to call GridFSInputFile.save().
    
    参数:
    
    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
    
    返回:
    
    a gridfs input file
  - createFile
```
public GridFSInputFile createFile(java.lang.String filename)
```
    Creates a file entry.
    
    参数:
    
    filename - the file name as stored in the db
    
    返回:
    
    a gridfs input file
    
    另请参阅:
    
    createFile()
  - 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.
    
    返回:
    
    GridFS file handle instance.
  - getBucketName
```
public java.lang.String getBucketName()
```
    Gets the bucket name used in the collection's namespace. Default value is 'fs'.
    
    返回:
    
    the name of the file bucket
  - getDB
```
public DB getDB()
```
    Gets the database used.
    
    返回:
    
    the database
  - getFilesCollection
```
protected DBCollection getFilesCollection()
```
    Gets the DBCollection in which the file's metadata is stored.
    
    返回:
    
    the collection
  - getChunksCollection
```
protected DBCollection getChunksCollection()
```
    Gets the DBCollection in which the binary chunks are stored.
    
    返回:
    
    the collection

类 GridFS

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

DEFAULT_CHUNKSIZE

MAX_CHUNKSIZE

DEFAULT_BUCKET

构造器详细资料

GridFS

GridFS

方法详细资料

getFileList

getFileList

getFileList

find

findOne

findOne

findOne

find

find

find

find

remove

remove

remove

createFile

createFile

createFile

createFile

createFile

createFile

createFile

createFile

getBucketName

getDB

getFilesCollection

getChunksCollection