org.apache.commons.vfs2

Interface FileContent

All Superinterfaces:

AutoCloseable, Closeable

All Known Implementing Classes:

DefaultFileContent

public interface FileContent
extends Closeable

Represents the data content of a file.

To read from a file, use the InputStream returned by getInputStream().

To write to a file, use the OutputStream returned by getOutputStream() method. This will create the file, and the parent folder, if necessary.

A file may have multiple InputStreams open at the same time.

See Also:

FileObject.getContent()

Method Summary

Modifier and Type	Method and Description
void	close() Closes all resources used by the content, including any open stream.
Object	getAttribute(String attrName) Gets the value of an attribute of the file's content.
String[]	getAttributeNames() Gets the attributes of the file's content.
Map<String,Object>	getAttributes() Returns a read-only map of this file's attributes.
default byte[]	getByteArray() Returns the content of a file as a byte array.
Certificate[]	getCertificates() Gets the certificates if any used to sign this file or folder.
FileContentInfo	getContentInfo() Gets the content info.
FileObject	getFile() Gets the file which this is the content of.
InputStream	getInputStream() Gets an input stream for reading the file's content.
default InputStream	getInputStream(int bufferSize) Gets an input stream for reading the file's content.
long	getLastModifiedTime() Gets the last-modified timestamp of the file.
OutputStream	getOutputStream() Gets an output stream for writing the file's content.
OutputStream	getOutputStream(boolean bAppend) Gets an output stream for writing the file's content.
default OutputStream	getOutputStream(boolean bAppend, int bufferSize) Gets an output stream for writing the file's content.
default OutputStream	getOutputStream(int bufferSize) Gets an output stream for writing the file's content.
RandomAccessContent	getRandomAccessContent(RandomAccessMode mode) Gets an stream for reading/writing the file's content.
long	getSize() Gets the size of the file, in bytes.
default String	getString(Charset charset) Returns the content of a file as a String.
default String	getString(String charset) Gets the content of a file as a String.
boolean	hasAttribute(String attrName) Checks if an attribute of the file's content exists.
default boolean	isEmpty() Checks if the receiver is empty.
boolean	isOpen() Checks if this file has open streams.
void	removeAttribute(String attrName) Removes the value of an attribute of the file's content.
void	setAttribute(String attrName, Object value) Sets the value of an attribute of the file's content.
void	setLastModifiedTime(long modTime) Sets the last-modified timestamp of the file.
long	write(FileContent output) Writes this content to another FileContent.
long	write(FileObject file) Writes this content to another FileObject.
long	write(OutputStream output) Writes this content to an OutputStream.
long	write(OutputStream output, int bufferSize) Writes this content to an OutputStream.

Method Detail

close

void close()
    throws FileSystemException

Closes all resources used by the content, including any open stream. Commits pending changes to the file.

This method is a hint to the implementation that it can release resources. This object can continue to be used after calling this method.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

FileSystemException - if an error occurs closing the file.

getAttribute

Object getAttribute(String attrName)
             throws FileSystemException

Gets the value of an attribute of the file's content.

Parameters:

attrName - The name of the attribute. Attribute names are case insensitive.

Returns:

The value of the attribute, or null if the attribute value is unknown.

Throws:

FileSystemException - If the file does not exist, or does not support attributes.

getAttributeNames

String[] getAttributeNames()
                    throws FileSystemException

Gets the attributes of the file's content.

Returns:

The names of the attributes. Never returns null;

Throws:

FileSystemException - If the file does not exist, or does not support attributes.

getAttributes

Map<String,Object> getAttributes()
                          throws FileSystemException

Returns a read-only map of this file's attributes.

Returns:

The attribute Map.

Throws:

FileSystemException - If the file does not exist, or does not support attributes.

getByteArray

default byte[] getByteArray()
                     throws IOException

Returns the content of a file as a byte array.

Returns:

The content as a byte array.

Throws:

IOException - if the file content cannot be accessed.

Since:

2.4

getCertificates

Certificate[] getCertificates()
                       throws FileSystemException

Gets the certificates if any used to sign this file or folder.

Returns:

The certificates, or an empty array if there are no certificates or the file does not support signing.

Throws:

FileSystemException - If the file does not exist, or is being written.

getContentInfo

FileContentInfo getContentInfo()
                        throws FileSystemException

Gets the content info. e.g. type, encoding, ...

Returns:

the FileContentInfo

Throws:

FileSystemException - if an error occurs.

getFile

FileObject getFile()

Gets the file which this is the content of.

Returns:

The FileObject this is the content of.

getInputStream

InputStream getInputStream()
                    throws FileSystemException

Gets an input stream for reading the file's content.

There may only be a single input or output stream open for the file at any time.

Returns:

An input stream to read the file's content from. The input stream is buffered, so there is no need to wrap it in a BufferedInputStream.

Throws:

FileSystemException - If the file does not exist, or is being read, or is being written, or on error opening the stream.

getInputStream

default InputStream getInputStream(int bufferSize)
                            throws FileSystemException

Gets an input stream for reading the file's content.

There may only be a single input or output stream open for the file at any time.

Parameters:

bufferSize - The buffer size to use.

Returns:

An input stream to read the file's content from. The input stream is buffered, so there is no need to wrap it in a BufferedInputStream.

Throws:

FileSystemException - If the file does not exist, or is being read, or is being written, or on error opening the stream.

Since:

2.4

getLastModifiedTime

long getLastModifiedTime()
                  throws FileSystemException

Gets the last-modified timestamp of the file.

Returns:

The last-modified timestamp.

Throws:

FileSystemException - If the file does not exist, or is being written to, or on error determining the last-modified timestamp.

getOutputStream

OutputStream getOutputStream()
                      throws FileSystemException

Gets an output stream for writing the file's content.

If the file does not exist, this method creates it, and the parent folder, if necessary. If the file does exist, it is replaced with whatever is written to the output stream.

There may only be a single input or output stream open for the file at any time.

Returns:

An output stream to write the file's content to. The stream is buffered, so there is no need to wrap it in a BufferedOutputStream.

Throws:

FileSystemException - If the file is read-only, or is being read, or is being written, or on error opening the stream.

getOutputStream

OutputStream getOutputStream(boolean bAppend)
                      throws FileSystemException

Gets an output stream for writing the file's content.

If the file does not exist, this method creates it, and the parent folder, if necessary. If the file does exist, it is replaced with whatever is written to the output stream.

There may only be a single input or output stream open for the file at any time.

Parameters:

bAppend - true if you would like to append to the file. This may not be supported by all implementations.

Returns:

An output stream to write the file's content to. The stream is buffered, so there is no need to wrap it in a BufferedOutputStream.

Throws:

FileSystemException - If the file is read-only, or is being read, or is being written, or bAppend is true and the implementation does not support it, or on error opening the stream.

getOutputStream

default OutputStream getOutputStream(boolean bAppend,
                                     int bufferSize)
                              throws FileSystemException

Gets an output stream for writing the file's content.

If the file does not exist, this method creates it, and the parent folder, if necessary. If the file does exist, it is replaced with whatever is written to the output stream.

There may only be a single input or output stream open for the file at any time.

Parameters:

bAppend - true if you would like to append to the file. This may not be supported by all implementations.

bufferSize - The buffer size to use.

Returns:

An output stream to write the file's content to. The stream is buffered, so there is no need to wrap it in a BufferedOutputStream.

Throws:

FileSystemException - If the file is read-only, or is being read, or is being written, or bAppend is true and the implementation does not support it, or on error opening the stream.

Since:

2.4

getOutputStream

default OutputStream getOutputStream(int bufferSize)
                              throws FileSystemException

Gets an output stream for writing the file's content.

If the file does not exist, this method creates it, and the parent folder, if necessary. If the file does exist, it is replaced with whatever is written to the output stream.

There may only be a single input or output stream open for the file at any time.

Parameters:

bufferSize - The buffer size to use.

Returns:

An output stream to write the file's content to. The stream is buffered, so there is no need to wrap it in a BufferedOutputStream.

Throws:

FileSystemException - If the file is read-only, or is being read, or is being written, or bAppend is true and the implementation does not support it, or on error opening the stream.

Since:

2.4

getRandomAccessContent

RandomAccessContent getRandomAccessContent(RandomAccessMode mode)
                                    throws FileSystemException

Gets an stream for reading/writing the file's content.

If the file does not exist, and you use one of the write* methods, this method creates it, and the parent folder, if necessary. If the file does exist, parts of the file are replaced with whatever is written at a given position.

There may only be a single input or output stream open for the file at any time.

Parameters:

mode - The mode to use to access the file.

Returns:

the stream for reading and writing the file's content.

Throws:

FileSystemException - If the file is read-only, or is being read, or is being written, or on error opening the stream.

getSize

long getSize()
      throws FileSystemException

Gets the size of the file, in bytes.

Returns:

The size of the file, in bytes.

Throws:

FileSystemException - If the file does not exist, or is being written to, or on error determining the size.

getString

default String getString(Charset charset)
                  throws IOException

Returns the content of a file as a String.

Parameters:

charset - The file character set, may be null.

Returns:

The content as a byte array.

Throws:

IOException - if the file content cannot be accessed.

Since:

2.4

getString

default String getString(String charset)
                  throws IOException

Gets the content of a file as a String.

Parameters:

charset - The file character set, may be null.

Returns:

The content as a byte array.

Throws:

IOException - if the file content cannot be accessed.

Since:

2.4

hasAttribute

boolean hasAttribute(String attrName)
              throws FileSystemException

Checks if an attribute of the file's content exists.

Parameters:

attrName - The name of the attribute.

Returns:

true if the attribute exists, false otherwise.

Throws:

FileSystemException - If the file does not exist, or does not support attributes.

isEmpty

default boolean isEmpty()
                 throws FileSystemException

Checks if the receiver is empty.

Returns:

true if the receiver is empty, false otherwise.

Throws:

FileSystemException - If the file does not exist, or is being written to, or on error determining the size.

Since:

2.5.0

isOpen

boolean isOpen()

Checks if this file has open streams.

Returns:

true if the file is open, false otherwise.

removeAttribute

void removeAttribute(String attrName)
              throws FileSystemException

Removes the value of an attribute of the file's content.

Parameters:

attrName - The name of the attribute.

Throws:

FileSystemException - If the file does not exist, or is read-only, or does not support attributes, or on error removing the attribute.

setAttribute

void setAttribute(String attrName,
                  Object value)
           throws FileSystemException

Sets the value of an attribute of the file's content. Creates the file if it does not exist.

Parameters:

attrName - The name of the attribute.

value - The value of the attribute.

Throws:

FileSystemException - If the file does not exist, or is read-only, or does not support attributes, or on error setting the attribute.

setLastModifiedTime

void setLastModifiedTime(long modTime)
                  throws FileSystemException

Sets the last-modified timestamp of the file. Creates the file if it does not exist.

Parameters:

modTime - The time to set the last-modified timestamp to.

Throws:

FileSystemException - If the file is read-only, or is being written to, or on error setting the last-modified timestamp.

write

long write(FileContent output)
    throws IOException

Writes this content to another FileContent.

Parameters:

output - The target OutputStream.

Returns:

the total number of bytes written

Throws:

IOException - if an error occurs writing the content.

Since:

2.1

write

long write(FileObject file)
    throws IOException

Writes this content to another FileObject.

Parameters:

file - The target FileObject.

Returns:

the total number of bytes written

Throws:

IOException - if an error occurs writing the content.

Since:

2.1

write

long write(OutputStream output)
    throws IOException

Writes this content to an OutputStream.

Parameters:

output - The target OutputStream.

Returns:

the total number of bytes written

Throws:

IOException - if an error occurs writing the content.

Since:

2.1

write

long write(OutputStream output,
           int bufferSize)
    throws IOException

Writes this content to an OutputStream.

Parameters:

output - The target OutputStream.

bufferSize - The buffer size to write data chunks.

Returns:

the total number of bytes written

Throws:

IOException - if an error occurs writing the file.

Since:

2.1