com.google.gwt.dev.util

Class FileBackedObject<T extends Serializable>

java.lang.Object

com.google.gwt.dev.util.FileBackedObject<T>

Type Parameters:

T - the type of object serialized into the file

All Implemented Interfaces:

PersistenceBackedObject<T>, Serializable

public class FileBackedObject<T extends Serializable>
extends Object
implements PersistenceBackedObject<T>

Represents a File that contains the serialized form of a Serializable object.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
FileBackedObject(Class<T> clazz) Constructs an empty FileBackedObject.
FileBackedObject(Class<T> clazz, File backingFile) Constructs a FileBackedObject using an existing File object.

Method Summary

Modifier and Type	Method and Description
boolean	exists() Returns whether the intended persistence location is already populated.
String	getPath() Returns the path to the intended persistence location.
T	newInstance(TreeLogger logger) Constructs and returns a new instance of the object stored at the path.
void	set(TreeLogger logger, T object) Serializes the provided object to the intended path.
String	toString()

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode

Constructor Detail

FileBackedObject

public FileBackedObject(Class<T> clazz)
                 throws IOException

Constructs an empty FileBackedObject. A temporary File will be used and this file will be deleted when the JVM exits.

Parameters:

clazz - the type of object to be serialized

Throws:

IOException - if the temporary file could not be created

FileBackedObject

public FileBackedObject(Class<T> clazz,
                        File backingFile)

Constructs a FileBackedObject using an existing File object.

Parameters:

clazz - the type of object to be serialized

backingFile - the file to read from or write to

Method Detail

exists

public boolean exists()

Description copied from interface: PersistenceBackedObject

Returns whether the intended persistence location is already populated. For example if persisting to a file this would be whether or not the file already exists.

Specified by:

exists in interface PersistenceBackedObject<T extends Serializable>

getPath

public String getPath()

Description copied from interface: PersistenceBackedObject

Returns the path to the intended persistence location.

Specified by:

getPath in interface PersistenceBackedObject<T extends Serializable>

newInstance

public T newInstance(TreeLogger logger)
              throws UnableToCompleteException

Description copied from interface: PersistenceBackedObject

Constructs and returns a new instance of the object stored at the path.

Specified by:

newInstance in interface PersistenceBackedObject<T extends Serializable>

Throws:

UnableToCompleteException - if the backing store does not contain an object of type T

set

public void set(TreeLogger logger,
                T object)
         throws IllegalStateException,
                UnableToCompleteException

Description copied from interface: PersistenceBackedObject

Serializes the provided object to the intended path. Can only be set once.

Specified by:

set in interface PersistenceBackedObject<T extends Serializable>

Throws:

UnableToCompleteException - if the object could not be serialized

IllegalStateException

toString

public String toString()

Overrides:

toString in class Object