DocumentCache (XMLmind XML Editor Java[tm] API)

java.lang.Object
- com.xmlmind.xml.load.DocumentCache

All Implemented Interfaces:

DocumentManager
```
public class DocumentCache
extends Object
implements DocumentManager
```
A Last Recently Used (LRU) document cache designed to have thousands of entries.
This class is thread-safe.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`DocumentCache.Entry` An entry in the document cache.
`static class`	`DocumentCache.Event` Rather low-level event detailing what happened to the document cache.
`static class`	`DocumentCache.EventType` The type of a document cache event.
`static interface`	`DocumentCache.Listener` Implemented by client code interested in learning what happens to this document cache.

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`capacity`
`static int`	`DEFAULT_CAPACITY` Default capacity (that is, the maximum number of cached documents) of a document cache.
`static int`	`DEFAULT_LOAD_OPTIONS` Default load document options.
`protected int`	`defaultLoadOptions`
`protected HashMap<URL,DocumentCache.Entry>`	`entries`
`protected DocumentCache.Event`	`event`
`protected DocumentCache.Entry`	`first`
`protected DocumentCache.Entry`	`last`
`protected DocumentCache.Listener[]`	`listeners`
`protected int`	`size`

Constructor Summary

Constructors
Constructor and Description
`DocumentCache()` Constructs a document cache having the default capacity and using the normal default load options.
`DocumentCache(int capacity, int defaultLoadOptions)` Constructs a document cache having specified capacity and using specified default load options.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected DocumentCache.Entry`	`accessEntry(URL url, boolean load, int loadOptions)`
`protected void`	`addEntry(DocumentCache.Entry e)`
`void`	`addListener(DocumentCache.Listener listener)` Register specified event listener.
`protected void`	`attachEntry(DocumentCache.Entry e)`
`protected boolean`	`checkedAddEntry(DocumentCache.Entry e)`
`void`	`clear()` Make this document cache empty.
`protected DocumentCache.Entry`	`createEntry(URL url, Document document, int loadOptions, File file, long lastModified, long size)`
`protected void`	`detachEntry(DocumentCache.Entry e)`
`protected DocumentCache.Entry`	`doAccessEntry(URL url, boolean load, int loadOptions)`
`protected void`	`doAddEntry(DocumentCache.Entry e)`
`protected void`	`doClear()`
`protected Document`	`doLoadDocument(InputSource source, URL url, int loadOptions, List<LoadError> loadErrors, List<LoadError> loadWarnings)`
`protected void`	`doRemoveEntry(DocumentCache.Entry e)`
`Document`	`fetch(URL url)` Just fetch -- do not load -- specified document from this cache.
`DocumentCache.Entry`	`fetchEntry(URL url)` Just fetch -- do not load -- specified document from this cache.
`Document`	`get(URL url)` Equivalent to `get(url, defaultLoadOptions)`.
`Document`	`get(URL url, int loadOptions)` Fetch specified document from this cache; load it if needed to.
`static DocumentCache`	`getCache()` Returns the application-wide document cache.
`int`	`getCapacity()` Returns the maximum number of cached documents.
`int`	`getDefaultLoadOptions()` Returns an OR-ed mask containing the default options of the document loader used by this cache.
`Document`	`getDocument(URL url)` Returns specified document.
`DocumentCache.Entry`	`getEntry(URL url)` Equivalent to `getEntry(url, defaultLoadOptions)`.
`DocumentCache.Entry`	`getEntry(URL url, int loadOptions)` Fetch specified document from this cache; load it if needed to.
`DocumentCache.Listener[]`	`getListeners()` Returns an array containing all registered event listeners.
`int`	`getSize()` Returns the number of documents currently cached in this cache.
`protected Document`	`loadDocument(InputStream in, URL url, int loadOptions)`
`protected DocumentCache.Entry`	`loadEntry(URL url, int loadOptions)`
`protected void`	`notifyListeners()`
`Document`	`remove(URL url)` Remove specified document from this cache.
`protected void`	`removeEntry(DocumentCache.Entry e)`
`DocumentCache.Entry`	`removeEntry(URL url)` Remove specified document from this cache.
`void`	`removeListener(DocumentCache.Listener listener)` Unregister specified event listener.
`static void`	`setCache(DocumentCache cache)` Specifies which cache to use as the application-wide document cache.
`void`	`setCapacity(int capacity)` Specifies the maximum number of cached documents.
`void`	`setDefaultLoadOptions(int defaultLoadOptions)` Changes the default options of the document loader used by this cache.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_CAPACITY
```
public static final int DEFAULT_CAPACITY
```
    Default capacity (that is, the maximum number of cached documents) of a document cache.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_LOAD_OPTIONS
```
public static final int DEFAULT_LOAD_OPTIONS
```
    Default load document options. These options are:
    - LoadOptions.ADD_ANY_DOCUMENT_TYPE. Needed to support xml:id.
    - LoadOptions.DONT_INCLUDE. Document cache client code is almost always interested in the intrinsic contents of a document.
    See Also:
    
    setDefaultLoadOptions(int), Constant Field Values
  - capacity
```
protected int capacity
```
  - defaultLoadOptions
```
protected int defaultLoadOptions
```
  - entries
```
protected HashMap<URL,DocumentCache.Entry> entries
```
  - first
```
protected DocumentCache.Entry first
```
  - last
```
protected DocumentCache.Entry last
```
  - size
```
protected int size
```
  - listeners
```
protected DocumentCache.Listener[] listeners
```
  - event
```
protected DocumentCache.Event event
```
- Constructor Detail
  - DocumentCache
```
public DocumentCache()
```
    Constructs a document cache having the default capacity and using the normal default load options.
    
    See Also:
    
    DEFAULT_CAPACITY, DEFAULT_LOAD_OPTIONS
  - DocumentCache
```
public DocumentCache(int capacity,
                     int defaultLoadOptions)
```
    Constructs a document cache having specified capacity and using specified default load options.
    
    Parameters:
    
    capacity - the maximum number of cached documents
    
    defaultLoadOptions - load options used by default. The getEntry(java.net.URL) method allows to specify a different value when needed to.
- Method Detail
  - setCapacity
```
public void setCapacity(int capacity)
```
    Specifies the maximum number of cached documents.
    
    See Also:
    
    getCapacity()
  - getCapacity
```
public int getCapacity()
```
    Returns the maximum number of cached documents.
    
    See Also:
    
    setCapacity(int)
  - setDefaultLoadOptions
```
public void setDefaultLoadOptions(int defaultLoadOptions)
```
    Changes the default options of the document loader used by this cache.
    Note that changing these options does not automatically clear the cache. You may want to do that manually by using clear().
    
    Parameters:
    
    defaultLoadOptions - an OR-ed mask containing the default options of the document loader used by this cache
    
    See Also:
    
    getDefaultLoadOptions(), LoadOptions
  - getDefaultLoadOptions
```
public int getDefaultLoadOptions()
```
    Returns an OR-ed mask containing the default options of the document loader used by this cache.
    
    See Also:
    
    setDefaultLoadOptions(int), LoadOptions
  - addListener
```
public void addListener(DocumentCache.Listener listener)
```
    Register specified event listener.
    
    See Also:
    
    removeListener(com.xmlmind.xml.load.DocumentCache.Listener), getListeners()
  - removeListener
```
public void removeListener(DocumentCache.Listener listener)
```
    Unregister specified event listener.
    
    See Also:
    
    addListener(com.xmlmind.xml.load.DocumentCache.Listener), getListeners()
  - getListeners
```
public DocumentCache.Listener[] getListeners()
```
    Returns an array containing all registered event listeners.
    
    See Also:
    
    addListener(com.xmlmind.xml.load.DocumentCache.Listener), removeListener(com.xmlmind.xml.load.DocumentCache.Listener)
  - notifyListeners
```
protected void notifyListeners()
```
  - getDocument
```
public Document getDocument(URL url)
                     throws IOException
```
    Returns specified document.
    Fetch specified document from this cache; load it if needed to.
    
    Specified by:
    
    getDocument in interface DocumentManager
    
    Parameters:
    
    url - URL of document
    
    Returns:
    
    document having specified URL; implementation may return null instead of throwing an IOException
    
    Throws:
    
    IOException - if specified document cannot be loaded
  - get
```
public Document get(URL url)
             throws IOException
```
    Equivalent to get(url, defaultLoadOptions).
    
    Throws:
    
    IOException
    
    See Also:
    
    getEntry(URL)
  - get
```
public Document get(URL url,
                    int loadOptions)
             throws IOException
```
    Fetch specified document from this cache; load it if needed to.
    
    Parameters:
    
    url - URL of the document to be fetched or loaded
    
    loadOptions - load options; used when the document needs to be loaded from disk
    
    Returns:
    
    specified document
    
    Throws:
    
    IOException - if an I/O error occurs when the document is accessed on disk
    
    See Also:
    
    getEntry(URL, int), fetch(java.net.URL)
  - getEntry
```
public DocumentCache.Entry getEntry(URL url)
                             throws IOException
```
    Equivalent to getEntry(url, defaultLoadOptions).
    
    Throws:
    
    IOException
    
    See Also:
    
    get(URL)
  - getEntry
```
public DocumentCache.Entry getEntry(URL url,
                                    int loadOptions)
                             throws IOException
```
    Fetch specified document from this cache; load it if needed to.
    
    Parameters:
    
    url - URL of the document to be fetched or loaded
    
    loadOptions - load options; used when the document needs to be loaded from disk
    
    Returns:
    
    the cache entry which corresponds to specified document
    
    Throws:
    
    IOException - if an I/O error occurs when the document is accessed on disk
    
    See Also:
    
    getEntry(URL, int), fetchEntry(java.net.URL)
  - fetch
```
public Document fetch(URL url)
```
    Just fetch -- do not load -- specified document from this cache.
    
    Parameters:
    
    url - URL of the document to be fetched
    
    Returns:
    
    document fetched from this cache or null
    
    See Also:
    
    fetchEntry(java.net.URL), get(URL)
  - fetchEntry
```
public DocumentCache.Entry fetchEntry(URL url)
```
    Just fetch -- do not load -- specified document from this cache.
    
    Parameters:
    
    url - URL of the document to be fetched
    
    Returns:
    
    the cache entry corresponding to specified document or null
    
    See Also:
    
    fetch(java.net.URL), getEntry(URL)
  - accessEntry
```
protected DocumentCache.Entry accessEntry(URL url,
                                          boolean load,
                                          int loadOptions)
                                   throws IOException
```
    Throws:
    
    IOException
  - doAccessEntry
```
protected DocumentCache.Entry doAccessEntry(URL url,
                                            boolean load,
                                            int loadOptions)
                                     throws IOException
```
    Throws:
    
    IOException
  - createEntry
```
protected DocumentCache.Entry createEntry(URL url,
                                          Document document,
                                          int loadOptions,
                                          File file,
                                          long lastModified,
                                          long size)
```
  - loadEntry
```
protected DocumentCache.Entry loadEntry(URL url,
                                        int loadOptions)
                                 throws IOException
```
    Throws:
    
    IOException
  - loadDocument
```
protected Document loadDocument(InputStream in,
                                URL url,
                                int loadOptions)
                         throws IOException
```
    Throws:
    
    IOException
  - doLoadDocument
```
protected Document doLoadDocument(InputSource source,
                                  URL url,
                                  int loadOptions,
                                  List<LoadError> loadErrors,
                                  List<LoadError> loadWarnings)
                           throws SAXException,
                                  IOException
```
    Throws:
    
    SAXException
    
    IOException
  - checkedAddEntry
```
protected boolean checkedAddEntry(DocumentCache.Entry e)
```
  - addEntry
```
protected void addEntry(DocumentCache.Entry e)
```
  - doAddEntry
```
protected void doAddEntry(DocumentCache.Entry e)
```
  - attachEntry
```
protected void attachEntry(DocumentCache.Entry e)
```
  - remove
```
public Document remove(URL url)
```
    Remove specified document from this cache.
    
    Parameters:
    
    url - URL of the document to be removed from this cache
    
    Returns:
    
    removed document or null if specified document was not cached
    
    See Also:
    
    removeEntry(java.net.URL)
  - removeEntry
```
public DocumentCache.Entry removeEntry(URL url)
```
    Remove specified document from this cache.
    
    Parameters:
    
    url - URL of the document to be removed from this cache
    
    Returns:
    
    the cache entry corresponding to removed document or null if specified document was not cached
    
    See Also:
    
    remove(java.net.URL)
  - removeEntry
```
protected void removeEntry(DocumentCache.Entry e)
```
  - doRemoveEntry
```
protected void doRemoveEntry(DocumentCache.Entry e)
```
  - detachEntry
```
protected void detachEntry(DocumentCache.Entry e)
```
  - clear
```
public void clear()
```
    Make this document cache empty.
  - doClear
```
protected void doClear()
```
  - getSize
```
public int getSize()
```
    Returns the number of documents currently cached in this cache.
  - setCache
```
public static void setCache(DocumentCache cache)
```
    Specifies which cache to use as the application-wide document cache.
    This initial application-wide document cache is automatically created using new DocumentCache().
    
    See Also:
    
    getCache()
  - getCache
```
public static DocumentCache getCache()
```
    Returns the application-wide document cache. Never returns null.
    
    See Also:
    
    setCache(com.xmlmind.xml.load.DocumentCache)

Class DocumentCache

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_CAPACITY

DEFAULT_LOAD_OPTIONS

capacity

defaultLoadOptions

entries

first

last

size

listeners

event

Constructor Detail

DocumentCache

DocumentCache

Method Detail

setCapacity

getCapacity

setDefaultLoadOptions

getDefaultLoadOptions

addListener

removeListener

getListeners

notifyListeners

getDocument

get

get

getEntry

getEntry

fetch

fetchEntry

accessEntry

doAccessEntry

createEntry

loadEntry

loadDocument

doLoadDocument

checkedAddEntry

addEntry

doAddEntry

attachEntry

remove

removeEntry

removeEntry

doRemoveEntry

detachEntry

clear

doClear

getSize

setCache

getCache