org.apache.james.mime4j.storage
Class StorageOutputStream

java.lang.Object
  extended by java.io.OutputStream
      extended by org.apache.james.mime4j.storage.StorageOutputStream
All Implemented Interfaces:
java.io.Closeable, java.io.Flushable

public abstract class StorageOutputStream
extends java.io.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
protected StorageOutputStream()
          Sole constructor.
 
Method Summary
 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
 
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 java.io.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:
java.io.IOException - if an I/O error occurs.
java.lang.IllegalStateException - if this method has already been called.

write

public final void write(int b)
                 throws java.io.IOException
Specified by:
write in class java.io.OutputStream
Throws:
java.io.IOException

write

public final void write(byte[] buffer)
                 throws java.io.IOException
Overrides:
write in class java.io.OutputStream
Throws:
java.io.IOException

write

public final void write(byte[] buffer,
                        int offset,
                        int length)
                 throws java.io.IOException
Overrides:
write in class java.io.OutputStream
Throws:
java.io.IOException

close

public void close()
           throws java.io.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 java.io.Closeable
Overrides:
close in class java.io.OutputStream
Throws:
java.io.IOException - if an I/O error occurs.

write0

protected abstract void write0(byte[] buffer,
                               int offset,
                               int length)
                        throws java.io.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:
java.io.IOException - if an I/O error occurs.

toStorage0

protected abstract Storage toStorage0()
                               throws java.io.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:
java.io.IOException - if an I/O error occurs.


Copyright © 2004-2012 The Apache Software Foundation. All Rights Reserved.