public class ContentQueryMap extends Observable
The cursor data is accessed by row key and column name via getValue().
|Constructor and Description|
Creates a ContentQueryMap that caches the content backing the cursor
|Modifier and Type||Method and Description|
Invoked when the garbage collector has detected that this instance is no longer reachable.
Access the ContentValues for the row specified by rowName
Requeries the cursor and reads the contents into the cache
Change whether or not the ContentQueryMap will register with the cursor's ContentProvider for change notifications.
addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged
public ContentQueryMap(Cursor cursor, String columnNameOfKey, boolean keepUpdated, Handler handlerForUpdateNotifications)
cursor- the cursor whose contents should be cached
columnNameOfKey- the column that is to be used as the key of the values map
keepUpdated- true if the cursor's ContentProvider should be monitored for changes and the map updated when changes do occur
handlerForUpdateNotifications- the Handler that should be used to receive notifications of changes (if requested). Normally you pass null here, but if you know that the thread that is creating this isn't a thread that can receive messages then you can create your own handler and use that here.
public void setKeepUpdated(boolean keepUpdated)
keepUpdated- if true the ContentQueryMap should be registered with the cursor's ContentProvider, false otherwise
public ContentValues getValues(String rowName)
rowName- which row to read
public void requery()
public void close()
protected void finalize() throws Throwable
Note that objects that override
finalize are significantly more expensive than
objects that don't. Finalizers may be run a long time after the object is no longer
reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup.
Note also that finalizers are run on a single VM-wide finalizer thread,
so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary
for a class that has a native peer and needs to call a native method to destroy that peer.
Even then, it's better to provide an explicit
close method (and implement
Closeable), and insist that callers manually dispose of instances. This
works well for something like files, but less well for something like a
where typical calling code would have to deal with lots of temporaries. Unfortunately,
code that creates lots of temporaries is the worst kind of code from the point of view of
the single finalizer thread.
If you must use finalizers, consider at least providing your own
ReferenceQueue and having your own thread process that queue.
Unlike constructors, finalizers are not automatically chained. You are responsible for
Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.