java.io
Class FileOutputStream

java.lang.Object
  java.io.OutputStream
      java.io.FileOutputStream

public class FileOutputStream
extends OutputStream

This classes allows a stream of data to be written to a disk file or any open FileDescriptor.

Field Summary

Fields inherited from class java.lang.Object

_VMO_elem, _VMO_flag, _VMO_monitor, _VMO_sign, _VMO_size, _VMO_threadId

Constructor Summary

FileOutputStream(File file)
This method initializes a FileOutputStream object to write to the specified File object.

FileOutputStream(File name, boolean append)
This method initializes a FileOutputStream object to write to the named file.

FileOutputStream(FileDescriptor fd)
This method initializes a FileOutputStream object to write to the file represented by the specified FileDescriptor object.

FileOutputStream(String name)
This method initializes a FileOutputStream object to write to the named file.

FileOutputStream(String name, boolean append)
This method initializes a FileOutputStream object to write to the named file.

Method Summary

void	close() This method closes the underlying file.
protected void	finalize() This method closes the stream when this object is being garbage collected.
FileDescriptor	getFD() This method returns a FileDescriptor object representing the file that is currently being written to
void	write(byte[] buf) This method writes all the bytes in the specified array to the file.
void	write(byte[] buf, int offset, int len) This method writes len bytes from the byte array buf to the file starting at index offset.
void	write(int b) This method writes a single byte of data to the file.

Methods inherited from class java.io.OutputStream

flush

Methods inherited from class java.lang.Object

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

Constructor Detail

FileOutputStream

public FileOutputStream(String name)
                 throws SecurityException,
                        IOException

This method initializes a FileOutputStream object to write to the named file. The file is created if it does not exist, and the bytes written are written starting at the beginning of the file.

Before opening a file, a security check is performed by calling the checkWrite method of the SecurityManager (if one exists) with the name of the file to be opened. An exception is thrown if writing is not allowed.

Parameters:

name - The name of the file this stream should write to

Throws:

SecurityException - If write access to the file is not allowed

IOException - If a non-security error occurs

FileOutputStream

public FileOutputStream(File file)
                 throws SecurityException,
                        IOException

This method initializes a FileOutputStream object to write to the specified File object. The file is created if it does not exist, and the bytes written are written starting at the beginning of the file.

Before opening a file, a security check is performed by calling the checkWrite method of the SecurityManager (if one exists) with the name of the file to be opened. An exception is thrown if writing is not allowed.

Parameters:

file - The File object this stream should write to

Throws:

SecurityException - If write access to the file is not allowed

IOException - If a non-security error occurs

FileOutputStream

public FileOutputStream(String name,
                        boolean append)
                 throws SecurityException,
                        IOException

This method initializes a FileOutputStream object to write to the named file. The file is created if it does not exist, and the bytes written are written starting at the beginning of the file if the append argument is false or at the end of the file if the append argument is true.

Before opening a file, a security check is performed by calling the checkWrite method of the SecurityManager (if one exists) with the name of the file to be opened. An exception is thrown if writing is not allowed.

Parameters:

name - The name of the file this stream should write to

append - true to append bytes to the end of the file, or false to write bytes to the beginning

Throws:

SecurityException - If write access to the file is not allowed

IOException - If a non-security error occurs

FileOutputStream

public FileOutputStream(File name,
                        boolean append)
                 throws SecurityException,
                        IOException

This method initializes a FileOutputStream object to write to the named file. The file is created if it does not exist, and the bytes written are written starting at the beginning of the file if the append argument is false or at the end of the file if the append argument is true.

Before opening a file, a security check is performed by calling the checkWrite method of the SecurityManager (if one exists) with the name of the file to be opened. An exception is thrown if writing is not allowed.

Parameters:

name - The File object this stream should write to

append - true to append bytes to the end of the file, or false to write bytes to the beginning

Throws:

SecurityException - If write access to the file is not allowed

IOException - If a non-security error occurs

FileOutputStream

public FileOutputStream(FileDescriptor fd)
                 throws SecurityException

This method initializes a FileOutputStream object to write to the file represented by the specified FileDescriptor object. This method does not create any underlying disk file or reposition the file pointer of the given descriptor. It assumes that this descriptor is ready for writing as is.

Before opening a file, a security check is performed by calling the checkWrite method of the SecurityManager (if one exists) with the specified FileDescriptor as an argument. An exception is thrown if writing is not allowed.

Parameters:

file - The FileDescriptor this stream should write to

Throws:

SecurityException - If write access to the file is not allowed

Method Detail

getFD

public final FileDescriptor getFD()
                           throws IOException

This method returns a FileDescriptor object representing the file that is currently being written to

Returns:

A FileDescriptor object for this stream

Throws:

IOException - If an error occurs

write

public void write(int b)
           throws IOException

This method writes a single byte of data to the file.

Specified by:

write in class OutputStream

Parameters:

b - The byte of data to write, passed as an int

Throws:

IOException - If an error occurs

write

public void write(byte[] buf)
           throws IOException

This method writes all the bytes in the specified array to the file.

Overrides:

write in class OutputStream

Parameters:

buf - The array of bytes to write to the file

Throws:

IOException - If an error occurs

write

public void write(byte[] buf,
                  int offset,
                  int len)
           throws IOException

This method writes len bytes from the byte array buf to the file starting at index offset.

Overrides:

write in class OutputStream

Parameters:

buf - The array of bytes to write to the file

offset - The offset into the array to start writing bytes from

len - The number of bytes to write to the file

Throws:

IOException - If an error occurs

close

public void close()
           throws IOException

This method closes the underlying file. Any further attempts to write to this stream will likely generate an exception since the file is closed.

Overrides:

close in class OutputStream

Throws:

IOException - If an error occurs

finalize

protected void finalize()
                 throws IOException

This method closes the stream when this object is being garbage collected.

Overrides:

finalize in class Object

Throws:

IOException - If an error occurs (ignored by the Java runtime)

See Also:

System.gc(), System.runFinalizersOnExit(boolean), java.lang.ref