org.apache.hadoop.fs

Class FSDataOutputStreamBuilder<S extends FSDataOutputStream,B extends FSDataOutputStreamBuilder<S,B>>

java.lang.Object

org.apache.hadoop.fs.impl.AbstractFSBuilderImpl<S,B>

org.apache.hadoop.fs.FSDataOutputStreamBuilder<S,B>

All Implemented Interfaces:

FSBuilder<S,B>

@InterfaceAudience.Public
 @InterfaceStability.Evolving
public abstract class FSDataOutputStreamBuilder<S extends FSDataOutputStream,B extends FSDataOutputStreamBuilder<S,B>>
extends AbstractFSBuilderImpl<S,B>

Builder for FSDataOutputStream and its subclasses. It is used to create FSDataOutputStream when creating a new file or appending an existing file on FileSystem. By default, it does not create parent directory that do not exist. FileSystem.createNonRecursive(Path, boolean, int, short, long, Progressable). To create missing parent directory, use recursive(). To be more generic, AbstractFSBuilderImpl.opt(String, int) and AbstractFSBuilderImpl.must(String, int) variants provide implementation-agnostic way to customize the builder. Each FS-specific builder implementation can interpret the FS-specific options accordingly, for example: // Don't if (fs instanceof FooFileSystem) { FooFileSystem fs = (FooFileSystem) fs; OutputStream out = dfs.createFile(path) .optionA() .optionB("value") .cache() .build() } else if (fs instanceof BarFileSystem) { ... } // Do OutputStream out = fs.createFile(path) .permission(perm) .bufferSize(bufSize) .opt("foofs:option.a", true) .opt("foofs:option.b", "value") .opt("barfs:cache", true) .must("foofs:cache", true) .must("barfs:cache-size", 256 * 1024 * 1024) .build(); If the option is not related to the file system, the option will be ignored. If the option is must, but not supported by the file system, a IllegalArgumentException will be thrown.

Field Summary

Fields inherited from class org.apache.hadoop.fs.impl.AbstractFSBuilderImpl

UNKNOWN_MANDATORY_KEY

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FSDataOutputStreamBuilder(FileSystem fileSystem, Path p) Constructor.

Method Summary

Modifier and Type	Method and Description
B	append() Append to an existing file (optional operation).
B	blockSize(long blkSize) Set block size.
B	bufferSize(int bufSize) Set the size of the buffer to be used.
abstract S	build() Create the FSDataOutputStream to write on the file system.
B	checksumOpt(org.apache.hadoop.fs.Options.ChecksumOpt chksumOpt) Set checksum opt.
B	create() Create an FSDataOutputStream at the specified path.
protected long	getBlockSize()
protected int	getBufferSize()
protected org.apache.hadoop.fs.Options.ChecksumOpt	getChecksumOpt()
protected EnumSet<CreateFlag>	getFlags()
protected FileSystem	getFS()
protected FsPermission	getPermission()
protected Progressable	getProgress()
protected short	getReplication()
abstract B	getThisBuilder() Return the concrete implementation of the builder instance.
protected boolean	isRecursive() Return true to create the parent directories if they do not exist.
B	overwrite(boolean overwrite) Set to true to overwrite the existing file.
B	permission(FsPermission perm) Set permission for the file.
B	progress(Progressable prog) Set the facility of reporting progress.
B	recursive() Create the parent directory if they do not exist.
B	replication(short replica) Set replication factor.

Methods inherited from class org.apache.hadoop.fs.impl.AbstractFSBuilderImpl

getMandatoryKeys, getOptionalKeys, getOptionalPath, getOptionalPathHandle, getOptions, getPath, getPathHandle, must, must, must, must, must, must, must, mustDouble, mustLong, opt, opt, opt, opt, opt, opt, opt, optDouble, optLong, rejectUnknownMandatoryKeys, rejectUnknownMandatoryKeys

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FSDataOutputStreamBuilder

protected FSDataOutputStreamBuilder(@Nonnull
                                    FileSystem fileSystem,
                                    @Nonnull
                                    Path p)

Constructor.

Parameters:

fileSystem - file system.

p - the path.

Method Detail

getThisBuilder

public abstract B getThisBuilder()

Return the concrete implementation of the builder instance.

Overrides:

getThisBuilder in class AbstractFSBuilderImpl<S extends FSDataOutputStream,B extends FSDataOutputStreamBuilder<S,B>>

Returns:

this object, typecast

getFS

protected FileSystem getFS()

getPermission

protected FsPermission getPermission()

permission

public B permission(@Nonnull
                    FsPermission perm)

Set permission for the file.

Parameters:

perm - permission.

Returns:

B Generics Type.

getBufferSize

protected int getBufferSize()

bufferSize

public B bufferSize(int bufSize)

Set the size of the buffer to be used.

Parameters:

bufSize - buffer size.

Returns:

Generics Type B.

getReplication

protected short getReplication()

replication

public B replication(short replica)

Set replication factor.

Parameters:

replica - replica.

Returns:

Generics Type B.

getBlockSize

protected long getBlockSize()

blockSize

public B blockSize(long blkSize)

Set block size.

Parameters:

blkSize - block size.

Returns:

B Generics Type.

isRecursive

protected boolean isRecursive()

Return true to create the parent directories if they do not exist.

Returns:

if create the parent directories if they do not exist true,not false.

recursive

public B recursive()

Create the parent directory if they do not exist.

Returns:

B Generics Type.

getProgress

protected Progressable getProgress()

progress

public B progress(@Nonnull
                  Progressable prog)

Set the facility of reporting progress.

Parameters:

prog - progress.

Returns:

B Generics Type.

getFlags

protected EnumSet<CreateFlag> getFlags()

create

public B create()

Create an FSDataOutputStream at the specified path.

Returns:

return Generics Type B.

overwrite

public B overwrite(boolean overwrite)

Set to true to overwrite the existing file. Set it to false, an exception will be thrown when calling build() if the file exists.

Parameters:

overwrite - overrite.

Returns:

Generics Type B.

append

public B append()

Append to an existing file (optional operation).

Returns:

Generics Type B.

getChecksumOpt

protected org.apache.hadoop.fs.Options.ChecksumOpt getChecksumOpt()

checksumOpt

public B checksumOpt(@Nonnull
                     org.apache.hadoop.fs.Options.ChecksumOpt chksumOpt)

Set checksum opt.

Parameters:

chksumOpt - check sum opt.

Returns:

Generics Type B.

build

public abstract S build()
                 throws IllegalArgumentException,
                        IOException

Create the FSDataOutputStream to write on the file system.

Returns:

generic type S.

Throws:

IllegalArgumentException - if the parameters are not valid.

IOException - on errors when file system creates or appends the file.