com.codename1.io

Class Storage

java.lang.Object

com.codename1.io.Storage

public class Storage
extends Object

Abstracts the underlying application specific storage system, unlike the FileSystemStorage this class is a higher level abstraction. The Storage class is designed to be very portable and as such it has no support for staple file system capabilities such as hierarchies.
Check out a more thorough discussion of this API here.

The sample code below shows a simple storage browser tool in action:

Constructor Summary

Constructors

Constructor and Description
Storage()

Method Summary

Modifier and Type	Method and Description
void	clearCache() Storage is cached for faster access, however this might cause a problem with refreshing objects since they are not cloned.
void	clearStorage() Deletes all the files in the application storage
InputStream	createInputStream(String name) Creates an input stream to the given storage source file
OutputStream	createOutputStream(String name) Creates an output stream to the storage with the given name
void	deleteStorageFile(String name) Deletes the given file name from the storage
int	entrySize(String name) Returns the size in bytes of the given entry
boolean	exists(String name) Returns true if the given storage file exists
void	flushStorageCache() Flush the storage cache allowing implementations that cache storage objects to store
static Storage	getInstance() Returns the storage instance or null if the storage wasn't initialized using a call to init(String) first.
static boolean	isInitialized() Returns true if the storage is initialized
boolean	isNormalizeNames() Indicates whether characters that are typically illegal in filesystems should be sanitized and replaced with underscore
String[]	listEntries() Lists the names of the storage files
Object	readObject(String name) Reads the object from the storage, returns null if the object isn't there
void	setHardCacheSize(int size) Indicates the caching size, storage can be pretty slow
void	setNormalizeNames(boolean normalizeNames) Indicates whether characters that are typically illegal in filesystems should be sanitized and replaced with underscore
static void	setStorageInstance(Storage s) Allows installing a custom storage instance to provide functionality such as seamless encryption
boolean	writeObject(String name, Object o) Writes the given object to storage assuming it is an externalizable type or one of the supported types.

Methods inherited from class java.lang.Object

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

Constructor Detail

Storage

public Storage()

Method Detail

setHardCacheSize

public void setHardCacheSize(int size)

Indicates the caching size, storage can be pretty slow

Parameters:

size - size in elements (not kb!)

isInitialized

public static boolean isInitialized()

Returns true if the storage is initialized

Returns:

true if the storage is initialized

getInstance

public static Storage getInstance()

Returns the storage instance or null if the storage wasn't initialized using a call to init(String) first.

Returns:

storage instance

clearCache

public void clearCache()

Storage is cached for faster access, however this might cause a problem with refreshing objects since they are not cloned. Clearing the cache allows to actually reload from the storage file.

flushStorageCache

public void flushStorageCache()

Flush the storage cache allowing implementations that cache storage objects to store

deleteStorageFile

public void deleteStorageFile(String name)

Deletes the given file name from the storage

Parameters:

name - the name of the storage file

clearStorage

public void clearStorage()

Deletes all the files in the application storage

createOutputStream

public OutputStream createOutputStream(String name)
                                throws IOException

Creates an output stream to the storage with the given name

Parameters:

name - the storage file name

Returns:

an output stream of limited capacity

Throws:

IOException

createInputStream

public InputStream createInputStream(String name)
                              throws IOException

Creates an input stream to the given storage source file

Parameters:

name - the name of the source file

Returns:

the input stream

Throws:

IOException

exists

public boolean exists(String name)

Returns true if the given storage file exists

Parameters:

name - the storage file name

Returns:

true if it exists

listEntries

public String[] listEntries()

Lists the names of the storage files

Returns:

the names of all the storage files

entrySize

public int entrySize(String name)

Returns the size in bytes of the given entry

Parameters:

name - the name of the entry

Returns:

the size in bytes

writeObject

public boolean writeObject(String name,
                           Object o)

Writes the given object to storage assuming it is an externalizable type or one of the supported types.

The sample below demonstrates the usage and registration of the Externalizable interface:

Parameters:

name - store name

o - object to store

Returns:

true for success, false for failure

readObject

public Object readObject(String name)

Reads the object from the storage, returns null if the object isn't there

The sample below demonstrates the usage and registration of the Externalizable interface:

Parameters:

name - name of the store

Returns:

object stored under that name

isNormalizeNames

public boolean isNormalizeNames()

Indicates whether characters that are typically illegal in filesystems should be sanitized and replaced with underscore

Returns:

the normalizeNames

setNormalizeNames

public void setNormalizeNames(boolean normalizeNames)

Indicates whether characters that are typically illegal in filesystems should be sanitized and replaced with underscore

Parameters:

normalizeNames - the normalizeNames to set

setStorageInstance

public static void setStorageInstance(Storage s)

Allows installing a custom storage instance to provide functionality such as seamless encryption

Parameters:

s - the storage instance