Package nl.siegmann.epublib.domain

Class LazyResource

java.lang.Object

nl.siegmann.epublib.domain.Resource

nl.siegmann.epublib.domain.LazyResource

All Implemented Interfaces:

Serializable

public class LazyResource
extends Resource

A Resource that loads its data only on-demand. This way larger books can fit into memory and can be opened faster.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private long	cachedSize
private String	filename
private static final org.slf4j.Logger	LOG
private static final long	serialVersionUID

Fields inherited from class nl.siegmann.epublib.domain.Resource

data, originalHref

Constructor Summary

Constructors

Constructor	Description
LazyResource(InputStream in, String filename, int length, String href)	Creates a Resource that tries to load the data, but falls back to lazy loading.
LazyResource(String filename, long size, String href)	Creates a Lazy resource, by not actually loading the data for this entry.

Method Summary

Modifier and Type	Method	Description
void	close()	Tells this resource to release its cached data.
byte[]	getData()	The contents of the resource as a byte[] If this resource was lazy-loaded and the data was not yet loaded, it will be loaded into memory at this point.
InputStream	getInputStream()	Gets the contents of the Resource as an InputStream.
private InputStream	getResourceStream()
long	getSize()	Returns the size of this resource in bytes.
void	initialize()	Initializes the resource by loading its data into memory.
boolean	isInitialized()	Returns if the data for this resource has been loaded into memory.

Methods inherited from class nl.siegmann.epublib.domain.Resource

equals, getHref, getId, getInputEncoding, getMediaType, getReader, getTitle, hashCode, setData, setHref, setId, setInputEncoding, setMediaType, setTitle, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

serialVersionUID

private static final long serialVersionUID

See Also:

• Constant Field Values

filename

private String filename

cachedSize

private long cachedSize

LOG

private static final org.slf4j.Logger LOG

Constructor Details

LazyResource

public LazyResource(String filename,
 long size,
 String href)

Creates a Lazy resource, by not actually loading the data for this entry. The data will be loaded on the first call to getData()

Parameters:

filename - the file name for the epub we're created from.

size - the size of this resource.

href - The resource's href within the epub.

LazyResource

public LazyResource(InputStream in,
 String filename,
 int length,
 String href)
             throws IOException

Creates a Resource that tries to load the data, but falls back to lazy loading. If the size of the resource is known ahead of time we can use that to allocate a matching byte[]. If this succeeds we can safely load the data. If it fails we leave the data null for now and it will be lazy-loaded when it is accessed.

Parameters:

in -

length -

href -

fileName -

Throws:

IOException

Method Details

getInputStream

public InputStream getInputStream()
                           throws IOException

Gets the contents of the Resource as an InputStream.

Overrides:

getInputStream in class Resource

Returns:

The contents of the Resource.

Throws:

IOException

initialize

public void initialize()
                throws IOException

Initializes the resource by loading its data into memory.

Throws:

IOException

getData

public byte[] getData()
               throws IOException

The contents of the resource as a byte[] If this resource was lazy-loaded and the data was not yet loaded, it will be loaded into memory at this point. This included opening the zip file, so expect a first load to be slow.

Overrides:

getData in class Resource

Returns:

The contents of the resource

Throws:

IOException

getResourceStream

private InputStream getResourceStream()
                               throws FileNotFoundException,
IOException

Throws:

FileNotFoundException

IOException

close

public void close()

Tells this resource to release its cached data. If this resource was not lazy-loaded, this is a no-op.

Overrides:

close in class Resource

isInitialized

public boolean isInitialized()

Returns if the data for this resource has been loaded into memory.

Returns:

true if data was loaded.

getSize

public long getSize()

Returns the size of this resource in bytes.

Overrides:

getSize in class Resource

Returns:

the size.