org.openstreetmap.josm.io
Class CacheCustomContent<T extends java.lang.Throwable>

java.lang.Object
  org.openstreetmap.josm.io.CacheCustomContent<T>

Type Parameters:

T - a Throwable that may be thrown during updateData(), use RuntimeException if no exception must be handled.

Direct Known Subclasses:

GettingStarted.MotdContent, OsmApi.CapabilitiesCache, TMSLayer.CachedAttributionBingAerialTileSource.BingAttributionData

public abstract class CacheCustomContent<T extends java.lang.Throwable>
extends java.lang.Object

Use this class if you want to cache and store a single file that gets updated regularly. Unless you flush() it will be kept in memory. If you want to cache a lot of data and/or files, use CacheFiles

Field Summary

private byte[]	data Where the data will be stored
private java.lang.String	ident The ident that identifies the stored file.
static int	INTERVAL_ALWAYS Common intervals
static int	INTERVAL_DAILY
static int	INTERVAL_HOURLY
static int	INTERVAL_MONTHLY
static int	INTERVAL_NEVER
static int	INTERVAL_WEEKLY
private java.io.File	path The (file-)path where the data will be stored
private int	updateInterval How often to update the cached version

Constructor Summary

CacheCustomContent(java.lang.String ident, int updateInterval)
Initializes the class.

Method Summary

void	flushData() Flushes the data from memory.
byte[]	getData() Returns the data without performing any updates
java.lang.String	getDataString() Returns the data without performing any updates
protected boolean	isCacheValid() This function serves as a comfort hook to perform additional checks if the cache is valid
private void	loadFromDisk() Tries to load the data using the given ident from disk.
private void	saveToDisk() Stores the data to disk
protected abstract byte[]	updateData() This function will be executed when an update is required.
byte[]	updateForce() Executes an update regardless of updateInterval
java.lang.String	updateForceString() Executes an update regardless of updateInterval
byte[]	updateIfRequired() Updates data if required
java.lang.String	updateIfRequiredString() Updates data if required

Methods inherited from class java.lang.Object

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

Field Detail

INTERVAL_ALWAYS

public static final int INTERVAL_ALWAYS

Common intervals

See Also:

Constant Field Values

INTERVAL_HOURLY

public static final int INTERVAL_HOURLY

See Also:

Constant Field Values

INTERVAL_DAILY

public static final int INTERVAL_DAILY

See Also:

Constant Field Values

INTERVAL_WEEKLY

public static final int INTERVAL_WEEKLY

See Also:

Constant Field Values

INTERVAL_MONTHLY

public static final int INTERVAL_MONTHLY

See Also:

Constant Field Values

INTERVAL_NEVER

public static final int INTERVAL_NEVER

See Also:

Constant Field Values

data

private byte[] data

Where the data will be stored

ident

private final java.lang.String ident

The ident that identifies the stored file. Includes file-ending.

path

private final java.io.File path

The (file-)path where the data will be stored

updateInterval

private final int updateInterval

How often to update the cached version

Constructor Detail

CacheCustomContent

public CacheCustomContent(java.lang.String ident,
                          int updateInterval)

Initializes the class. Note that all read data will be stored in memory until it is flushed by flushData().

Parameters:

ident -

updateInterval -

Method Detail

updateData

protected abstract byte[] updateData()
                              throws T extends java.lang.Throwable

This function will be executed when an update is required. It has to be implemented by the inheriting class and should use a worker if it has a long wall time as the function is executed in the current thread.

Returns:

the data to cache

Throws:

T extends java.lang.Throwable

isCacheValid

protected boolean isCacheValid()

This function serves as a comfort hook to perform additional checks if the cache is valid

Returns:

True if the cached copy is still valid

updateIfRequired

public byte[] updateIfRequired()
                        throws T extends java.lang.Throwable

Updates data if required

Returns:

Returns the data

Throws:

T extends java.lang.Throwable

updateIfRequiredString

public java.lang.String updateIfRequiredString()
                                        throws T extends java.lang.Throwable

Updates data if required

Returns:

Returns the data as string

Throws:

T extends java.lang.Throwable

updateForce

public byte[] updateForce()
                   throws T extends java.lang.Throwable

Executes an update regardless of updateInterval

Returns:

Returns the data

Throws:

T extends java.lang.Throwable

updateForceString

public java.lang.String updateForceString()
                                   throws T extends java.lang.Throwable

Executes an update regardless of updateInterval

Returns:

Returns the data as String

Throws:

T extends java.lang.Throwable

getData

public byte[] getData()
               throws T extends java.lang.Throwable

Returns the data without performing any updates

Returns:

the data

Throws:

T extends java.lang.Throwable

getDataString

public java.lang.String getDataString()
                               throws T extends java.lang.Throwable

Returns the data without performing any updates

Returns:

the data as String

Throws:

T extends java.lang.Throwable

loadFromDisk

private void loadFromDisk()
                   throws T extends java.lang.Throwable

Tries to load the data using the given ident from disk. If this fails, data will be updated

Throws:

T extends java.lang.Throwable

saveToDisk

private void saveToDisk()

Stores the data to disk

flushData

public void flushData()

Flushes the data from memory. Class automatically reloads it from disk or updateData() if required