Module org.tentackle.common

Package org.tentackle.common

Class Binary<T extends Serializable>

java.lang.Object

org.tentackle.common.Binary<T>

Type Parameters:

T - the serializable type

All Implemented Interfaces:

Serializable, Cloneable, Freezable

public class Binary<T extends Serializable>
extends Object
implements Serializable, Cloneable, Freezable

Datatype for storing arbitrary (binary) data in a database.

It uses the XXXBinaryStream-methods to read and write the data avoiding the transactional limits of blobs, because blobs usually are only valid within a transaction. Binary instead provides a blob-like interface while remaining valid outside transactions.

Furthermore, binaries can be frozen, i.e. made immutable.

Keep in mind that the wrapped object is serialized when the Binary is created or setObject is invoked. Any subsequent changes to the object are not reflected in the internal byte array.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
Binary()	Creates an empty binary.
Binary(T object)	Creates a Binary from a Serializable.

Method Summary

Modifier and Type	Method	Description
Binary<T>	clone()
static <T extends Serializable> Binary<T>	createBinary(InputStream stream, int bufSize, boolean frozen)	Creates a Binary out of an InputStream.
boolean	equals(Object o)
void	freeze()	Makes this object immutable.
InputStream	getInputStream()	Gets the stream to store the Binary in the database.
int	getLength()	Gets the length in bytes of this Binary.
T	getObject()	Retrieves the object encapsulated by the Binary.
int	hashCode()
void	setObject(T object)	Sets the serializable.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Binary

public Binary(T object)
       throws IOException

Creates a Binary from a Serializable.

Parameters:

object - the Serializable to be stored in the database

Throws:

IOException - if some serialization error.

Binary

public Binary()

Creates an empty binary.

Method Detail

freeze

public void freeze()

Description copied from interface: Freezable

Makes this object immutable.

Specified by:

freeze in interface Freezable

clone

public Binary<T> clone()

Cloned binaries are always not frozen.

Overrides:

clone in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

createBinary

public static <T extends Serializable> Binary<T> createBinary(InputStream stream,
                                                              int bufSize,
                                                              boolean frozen)
                                                       throws IOException

Creates a Binary out of an InputStream. Used to read a Binary from the database. Notice that stream.available() cannot be used according to sun's spec. The stream is closed after creating the Binary.

Type Parameters:

T - the serializable type

Parameters:

stream - the InputStream (associated to the database) to read from, may be null

bufSize - the initial buffer size, 0 = default size (bufSize)

frozen - true if binary is frozen

Returns:

the new Binary or null if stream is null or empty.

Throws:

IOException - if reading from the input stream failed

getLength

public int getLength()

Gets the length in bytes of this Binary. The length of a Binary is either the length of a byte-array (if Binary(byte[]) used) or the length of the serialized object (if Binary(Object) used)

Returns:

the length of the Binary in bytes

getInputStream

public InputStream getInputStream()

Gets the stream to store the Binary in the database.

Returns:

the stream associated to the database.

getObject

public T getObject()
            throws IOException,
                   ClassNotFoundException

Retrieves the object encapsulated by the Binary.

Returns:

the de-serialized object (retrieved from the db), or null if NULL-value

Throws:

IOException - if reading the object failed

ClassNotFoundException - if class of a serialized object cannot be found.

setObject

public void setObject(T object)
               throws IOException

Sets the serializable.

Parameters:

object - the serializable object.

Throws:

IOException - if object could not be serialized