Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Ctors](https://developer.android.com/reference/android/content/ContentQueryMap#pubctors) \| [Methods](https://developer.android.com/reference/android/content/ContentQueryMap#pubmethods) \| [Protected Methods](https://developer.android.com/reference/android/content/ContentQueryMap#promethods) \| [Inherited Methods](https://developer.android.com/reference/android/content/ContentQueryMap#inhmethods)

# ContentQueryMap

*** ** * ** ***


`
public


class
ContentQueryMap
`


`


`

`

extends https://developer.android.com/reference/java/util/Observable


`

`


`

|---|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) |||
| ↳ | [java.util.Observable](https://developer.android.com/reference/java/util/Observable) ||
|   | ↳ | android.content.ContentQueryMap |

<br />

*** ** * ** ***

Caches the contents of a cursor into a Map of String-\>ContentValues and optionally
keeps the cache fresh by registering for updates on the content backing the cursor. The column of
the database that is to be used as the key of the map is user-configurable, and the
ContentValues contains all columns other than the one that is designated the key.


The cursor data is accessed by row key and column name via getValue().

## Summary

| ### Public constructors ||
|---|---|
| ` https://developer.android.com/reference/android/content/ContentQueryMap#ContentQueryMap(android.database.Cursor,%20java.lang.String,%20boolean,%20android.os.Handler)(https://developer.android.com/reference/android/database/Cursor cursor, https://developer.android.com/reference/java/lang/String columnNameOfKey, boolean keepUpdated, https://developer.android.com/reference/android/os/Handler handlerForUpdateNotifications) ` Creates a ContentQueryMap that caches the content backing the cursor |

| ### Public methods ||
|---|---|
| ` void` | ` https://developer.android.com/reference/android/content/ContentQueryMap#close()() ` |
| ` https://developer.android.com/reference/java/util/Map<https://developer.android.com/reference/java/lang/String, https://developer.android.com/reference/android/content/ContentValues>` | ` https://developer.android.com/reference/android/content/ContentQueryMap#getRows()() ` |
| ` https://developer.android.com/reference/android/content/ContentValues` | ` https://developer.android.com/reference/android/content/ContentQueryMap#getValues(java.lang.String)(https://developer.android.com/reference/java/lang/String rowName) ` Access the ContentValues for the row specified by rowName |
| ` void` | ` https://developer.android.com/reference/android/content/ContentQueryMap#requery()() ` Requeries the cursor and reads the contents into the cache |
| ` void` | ` https://developer.android.com/reference/android/content/ContentQueryMap#setKeepUpdated(boolean)(boolean keepUpdated) ` Change whether or not the ContentQueryMap will register with the cursor's ContentProvider for change notifications. |

| ### Protected methods ||
|---|---|
| ` void` | ` https://developer.android.com/reference/android/content/ContentQueryMap#finalize()() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. |

| ### Inherited methods |
|---|---|
| From class ` https://developer.android.com/reference/java/util/Observable ` |---|---| | ` void` | ` https://developer.android.com/reference/java/util/Observable#addObserver(java.util.Observer)(https://developer.android.com/reference/java/util/Observer o) ` Adds an observer to the set of observers for this object, provided that it is not the same as some observer already in the set. | | ` void` | ` https://developer.android.com/reference/java/util/Observable#clearChanged()() ` Indicates that this object has no longer changed, or that it has already notified all of its observers of its most recent change, so that the `hasChanged` method will now return `false`. | | ` int` | ` https://developer.android.com/reference/java/util/Observable#countObservers()() ` Returns the number of observers of this `Observable` object. | | ` void` | ` https://developer.android.com/reference/java/util/Observable#deleteObserver(java.util.Observer)(https://developer.android.com/reference/java/util/Observer o) ` Deletes an observer from the set of observers of this object. | | ` void` | ` https://developer.android.com/reference/java/util/Observable#deleteObservers()() ` Clears the observer list so that this object no longer has any observers. | | ` boolean` | ` https://developer.android.com/reference/java/util/Observable#hasChanged()() ` Tests if this object has changed. | | ` void` | ` https://developer.android.com/reference/java/util/Observable#notifyObservers(java.lang.Object)(https://developer.android.com/reference/java/lang/Object arg) ` If this object has changed, as indicated by the `hasChanged` method, then notify all of its observers and then call the `clearChanged` method to indicate that this object has no longer changed. | | ` void` | ` https://developer.android.com/reference/java/util/Observable#notifyObservers()() ` If this object has changed, as indicated by the `hasChanged` method, then notify all of its observers and then call the `clearChanged` method to indicate that this object has no longer changed. | | ` void` | ` https://developer.android.com/reference/java/util/Observable#setChanged()() ` Marks this `Observable` object as having been changed; the `hasChanged` method will now return `true`. | ||
| From class ` https://developer.android.com/reference/java/lang/Object ` |---|---| | ` https://developer.android.com/reference/java/lang/Object` | ` https://developer.android.com/reference/java/lang/Object#clone()() ` Creates and returns a copy of this object. | | ` boolean` | ` https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) ` Indicates whether some other object is "equal to" this one. | | ` void` | ` https://developer.android.com/reference/java/lang/Object#finalize()() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ` final https://developer.android.com/reference/java/lang/Class<?>` | ` https://developer.android.com/reference/java/lang/Object#getClass()() ` Returns the runtime class of this `Object`. | | ` int` | ` https://developer.android.com/reference/java/lang/Object#hashCode()() ` Returns a hash code value for the object. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#notify()() ` Wakes up a single thread that is waiting on this object's monitor. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#notifyAll()() ` Wakes up all threads that are waiting on this object's monitor. | | ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/lang/Object#toString()() ` Returns a string representation of the object. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#wait(long,%20int)(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#wait(long)(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#wait()() ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*. | ||

## Public constructors

### ContentQueryMap

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public ContentQueryMap (Cursor cursor, 
                String columnNameOfKey, 
                boolean keepUpdated, 
                Handler handlerForUpdateNotifications)
```

Creates a ContentQueryMap that caches the content backing the cursor

<br />

| Parameters ||
|---|---|
| `cursor` | `Cursor`: the cursor whose contents should be cached <br /> |
| `columnNameOfKey` | `String`: the column that is to be used as the key of the values map <br /> |
| `keepUpdated` | `boolean`: true if the cursor's ContentProvider should be monitored for changes and the map updated when changes do occur <br /> |
| `handlerForUpdateNotifications` | `Handler`: 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. <br /> |

## Public methods

### close

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void close ()
```

<br />

<br />

### getRows

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public Map<String, ContentValues> getRows ()
```

<br />

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/util/Map<https://developer.android.com/reference/java/lang/String, https://developer.android.com/reference/android/content/ContentValues>` | <br /> |

### getValues

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public ContentValues getValues (String rowName)
```

Access the ContentValues for the row specified by rowName

<br />

| Parameters ||
|---|---|
| `rowName` | `String`: which row to read <br /> |

| Returns ||
|---|---|
| `https://developer.android.com/reference/android/content/ContentValues` | the ContentValues for the row, or null if the row wasn't present in the cursor <br /> |

### requery

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void requery ()
```

Requeries the cursor and reads the contents into the cache

<br />

### setKeepUpdated

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void setKeepUpdated (boolean keepUpdated)
```

Change whether or not the ContentQueryMap will register with the cursor's ContentProvider
for change notifications. If you use a ContentQueryMap in an activity you should call this
with false in onPause(), which means you need to call it with true in onResume()
if want it to be kept updated.

<br />

| Parameters ||
|---|---|
| `keepUpdated` | `boolean`: if true the ContentQueryMap should be registered with the cursor's ContentProvider, false otherwise <br /> |

## Protected methods

### finalize

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
protected void finalize ()
```

Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
A subclass overrides the `finalize` method to dispose of
system resources or to perform other cleanup.


The general contract of `finalize` is that it is invoked
if and when the Java virtual
machine has determined that there is no longer any
means by which this object can be accessed by any thread that has
not yet died, except as a result of an action taken by the
finalization of some other object or class which is ready to be
finalized. The `finalize` method may take any action, including
making this object available again to other threads; the usual purpose
of `finalize`, however, is to perform cleanup actions before
the object is irrevocably discarded. For example, the finalize method
for an object that represents an input/output connection might perform
explicit I/O transactions to break the connection before the object is
permanently discarded.


The `finalize` method of class `Object` performs no
special action; it simply returns normally. Subclasses of
`Object` may override this definition.


The Java programming language does not guarantee which thread will
invoke the `finalize` method for any given object. It is
guaranteed, however, that the thread that invokes finalize will not
be holding any user-visible synchronization locks when finalize is
invoked. If an uncaught exception is thrown by the finalize method,
the exception is ignored and finalization of that object terminates.


After the `finalize` method has been invoked for an object, no
further action is taken until the Java virtual machine has again
determined that there is no longer any means by which this object can
be accessed by any thread that has not yet died, including possible
actions by other objects or classes which are ready to be finalized,
at which point the object may be discarded.


The `finalize` method is never invoked more than once by a Java
virtual machine for any given object.


Any exception thrown by the `finalize` method causes
the finalization of this object to be halted, but is otherwise
ignored.

<br />

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/lang/Throwable` |   |