Package org.apache.james.mime4j.storage

Class StorageOutputStream

java.lang.Object

java.io.OutputStream

org.apache.james.mime4j.storage.StorageOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public abstract class StorageOutputStream
extends OutputStream

This class implements an output stream that can be used to create a Storage object. An instance of this class is obtained by calling StorageProvider.createStorageOutputStream(). The user can then write data to this instance and invoke toStorage() to retrieve a Storage object that contains the data that has been written.

Note that the StorageOutputStream does not have to be closed explicitly because toStorage() invokes close() if necessary. Also note that toStorage() may be invoked only once. One StorageOutputStream can create only one Storage instance.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	StorageOutputStream()	Sole constructor.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this output stream.
Storage	toStorage()	Closes this output stream if it has not already been closed and returns a Storage object which contains the bytes that have been written to this output stream.
protected abstract Storage	toStorage0()	Has to be implemented by a concrete subclass to create a Storage object from the bytes that have been written to this StorageOutputStream.
void	write(byte[] buffer)
void	write(byte[] buffer, int offset, int length)
void	write(int b)
protected abstract void	write0(byte[] buffer, int offset, int length)	Has to implemented by a concrete subclass to write bytes from the given byte array to this StorageOutputStream.

Methods inherited from class java.io.OutputStream

flush, nullOutputStream

Methods inherited from class java.lang.Object

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

Constructor Detail

StorageOutputStream

protected StorageOutputStream()

Sole constructor.

Method Detail

toStorage

public final Storage toStorage()
                        throws IOException

Closes this output stream if it has not already been closed and returns a Storage object which contains the bytes that have been written to this output stream.

Note that this method may not be invoked a second time. This is because for some implementations it is not possible to create another Storage object that can be read from and deleted independently (e.g. if the implementation writes to a file).

Returns:

a Storage object as described above.

Throws:

IOException - if an I/O error occurs.

IllegalStateException - if this method has already been called.

write

public final void write(int b)
                 throws IOException

Specified by:

write in class OutputStream

Throws:

IOException

write

public final void write(byte[] buffer)
                 throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

write

public final void write(byte[] buffer,
                        int offset,
                        int length)
                 throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

close

public void close()
           throws IOException

Closes this output stream. Subclasses that override this method have to invoke super.close().

This implementation never throws an IOException but a subclass might.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class OutputStream

Throws:

IOException - if an I/O error occurs.

write0

protected abstract void write0(byte[] buffer,
                               int offset,
                               int length)
                        throws IOException

Has to implemented by a concrete subclass to write bytes from the given byte array to this StorageOutputStream. This method gets called by write(int), write(byte[]) and write(byte[], int, int). All the required preconditions have already been checked by these methods, including the check if the output stream has already been closed.

Parameters:

buffer - buffer containing bytes to write.

offset - start offset in the buffer.

length - number of bytes to write.

Throws:

IOException - if an I/O error occurs.

toStorage0

protected abstract Storage toStorage0()
                               throws IOException

Has to be implemented by a concrete subclass to create a Storage object from the bytes that have been written to this StorageOutputStream. This method gets called by toStorage() after the preconditions have been checked. The implementation can also be sure that this methods gets invoked only once.

Returns:

a Storage object as described above.

Throws:

IOException - if an I/O error occurs.