Class FileOutputStream

public FileOutputStream(File file)
            throws SecurityException,
                   FileNotFoundException

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

FileNotFoundException - If a non-security error occurs

public FileOutputStream(File file,
                        boolean append)
            throws FileNotFoundException

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 if the append parameter is false. Otherwise bytes are written at the end 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

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

FileNotFoundException - If a non-security error occurs

public FileOutputStream(FileDescriptor fdObj)
            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:

fdObj - The FileDescriptor this stream should write to

Throws:

SecurityException - If write access to the file is not allowed

public FileOutputStream(String path)
            throws SecurityException,
                   FileNotFoundException

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:

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

Throws:

SecurityException - If write access to the file is not allowed

FileNotFoundException - If a non-security error occurs

public FileOutputStream(String path,
                        boolean append)
            throws SecurityException,
                   FileNotFoundException

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:

path - 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

FileNotFoundException - If a non-security error occurs

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.

Specified by:

close in interface Closeable

close in interface AutoCloseable

Overrides:

close in interface OutputStream

Throws:

IOException - If an error occurs

protected void finalize()
            throws IOException

Called on an object by the Virtual Machine at most once, at some point after the Object is determined unreachable but before it is destroyed. You would think that this means it eventually is called on every Object, but this is not necessarily the case. If execution terminates abnormally, garbage collection does not always happen. Thus you cannot rely on this method to always work. For finer control over garbage collection, use references from the java.lang.ref package.

Virtual Machines are free to not call this method if they can determine that it does nothing important; for example, if your class extends Object and overrides finalize to do simply super.finalize().

finalize() will be called by a Thread that has no locks on any Objects, and may be called concurrently. There are no guarantees on the order in which multiple objects are finalized. This means that finalize() is usually unsuited for performing actions that must be thread-safe, and that your implementation must be use defensive programming if it is to always work.

If an Exception is thrown from finalize() during garbage collection, it will be patently ignored and the Object will still be destroyed.

It is allowed, although not typical, for user code to call finalize() directly. User invocation does not affect whether automatic invocation will occur. It is also permitted, although not recommended, for a finalize() method to "revive" an object by making it reachable from normal code again.

Unlike constructors, finalize() does not get called for an object's superclass unless the implementation specifically calls super.finalize().

The default implementation does nothing.

Overrides:

finalize in interface Object

See Also:

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

public FileChannel getChannel()

This method creates a java.nio.channels.FileChannel. Nio does not allow one to create a file channel directly. A file channel must be created by first creating an instance of Input/Output/RandomAccessFile and invoking the getChannel() method on it.

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

public void write(byte[] buf)
            throws IOException

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

Overrides:

write in interface OutputStream

Parameters:

buf - The array of bytes to write to the file

Throws:

IOException - If an error occurs

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 interface 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

public void write(int b)
            throws IOException

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

Overrides:

write in interface OutputStream

Parameters:

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

Throws:

IOException - If an error occurs