# InvalidationTracker.Observer

added in[version 1.1.0](https://developer.android.com/topic/libraries/support-library/revisions)  
belongs to Maven artifact android.arch.persistence.room:runtime:1.1.0-beta2  
Summary:[Ctors](https://developer.android.com/reference/android/arch/persistence/room/InvalidationTracker.Observer#pubctors)\|[Protected Ctors](https://developer.android.com/reference/android/arch/persistence/room/InvalidationTracker.Observer#proctors)\|[Methods](https://developer.android.com/reference/android/arch/persistence/room/InvalidationTracker.Observer#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/android/arch/persistence/room/InvalidationTracker.Observer#inhmethods)  

# InvalidationTracker.Observer

| The`android.arch`Architecture Components packages are no longer maintained. They have been superseded by the corresponding[androidx.\*](https://developer.android.com/jetpack/androidx/migrate)packages. See[androidx.room.InvalidationTracker.Observer](https://developer.android.com/reference/androidx/room/InvalidationTracker.Observer)instead.

`
public
static

abstract
class
InvalidationTracker.Observer
`  
`

extends Object


``


`

|---|------------------------------------------------------------|
| java.lang.Object                                              ||
| ↳ | android.arch.persistence.room.InvalidationTracker.Observer |

<br />

*** ** * ** ***

An observer that can listen for changes in the database.

## Summary

|                                                                                                             ### Public constructors                                                                                                              ||
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ` `[InvalidationTracker.Observer](https://developer.android.com/reference/android/arch/persistence/room/InvalidationTracker.Observer#InvalidationTracker.Observer(java.lang.String[]))`(String[] tables) ` Observes the given list of tables. |

|                                                                                                                              ### Protected constructors                                                                                                                               ||
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ` `[InvalidationTracker.Observer](https://developer.android.com/reference/android/arch/persistence/room/InvalidationTracker.Observer#InvalidationTracker.Observer(java.lang.String, java.lang.String...))`(String firstTable, String... rest) ` Observes the given list of tables. |

|                                                                                                                                  ### Public methods                                                                                                                                   ||
|------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` abstract void` | ` `[onInvalidated](https://developer.android.com/reference/android/arch/persistence/room/InvalidationTracker.Observer#onInvalidated(java.util.Set<java.lang.String>))`(Set<String> tables) ` Called when one of the observed tables is invalidated in the database. |

| ### Inherited methods |
|-----------------------|---|
| From class` java.lang.Object ` |-------------------|-------------------------------| | ` Object`         | ` clone() `                   | | ` boolean`        | ` equals(Object arg0) `       | | ` void`           | ` finalize() `                | | ` final Class<?>` | ` getClass() `                | | ` int`            | ` hashCode() `                | | ` final void`     | ` notify() `                  | | ` final void`     | ` notifyAll() `               | | ` String`         | ` toString() `                | | ` final void`     | ` wait(long arg0, int arg1) ` | | ` final void`     | ` wait(long arg0) `           | | ` final void`     | ` wait() `                    | ||

## Public constructors

### InvalidationTracker.Observer

added in[version 1.1.0](https://developer.android.com/topic/libraries/support-library/revisions)  

```
InvalidationTracker.Observer (String[] tables)
```

Observes the given list of tables.

<br />

|                              Parameters                               ||
|----------|-------------------------------------------------------------|
| `tables` | `String`: The list of tables to observe for changes. <br /> |

## Protected constructors

### InvalidationTracker.Observer

added in[version 1.1.0](https://developer.android.com/topic/libraries/support-library/revisions)  

```
InvalidationTracker.Observer (String firstTable, 
                String... rest)
```

Observes the given list of tables.

<br />

|                   Parameters                    ||
|--------------|-----------------------------------|
| `firstTable` | `String`: The table name <br />   |
| `rest`       | `String`: More table names <br /> |

## Public methods

### onInvalidated

added in[version 1.1.0](https://developer.android.com/topic/libraries/support-library/revisions)  

```
void onInvalidated (Set<String> tables)
```

Called when one of the observed tables is invalidated in the database.

<br />

|                                                                         Parameters                                                                         ||
|----------|--------------------------------------------------------------------------------------------------------------------------------------------------|
| `tables` | `Set`: A set of invalidated tables. This is useful when the observer targets multiple tables and want to know which table is invalidated. <br /> |

-

  ## Annotations

  - [ColumnInfo](https://developer.android.com/reference/android/arch/persistence/room/ColumnInfo)
  - [ColumnInfo.Collate](https://developer.android.com/reference/android/arch/persistence/room/ColumnInfo.Collate)
  - [ColumnInfo.SQLiteTypeAffinity](https://developer.android.com/reference/android/arch/persistence/room/ColumnInfo.SQLiteTypeAffinity)
  - [Dao](https://developer.android.com/reference/android/arch/persistence/room/Dao)
  - [Database](https://developer.android.com/reference/android/arch/persistence/room/Database)
  - [Delete](https://developer.android.com/reference/android/arch/persistence/room/Delete)
  - [Embedded](https://developer.android.com/reference/android/arch/persistence/room/Embedded)
  - [Entity](https://developer.android.com/reference/android/arch/persistence/room/Entity)
  - [ForeignKey](https://developer.android.com/reference/android/arch/persistence/room/ForeignKey)
  - [ForeignKey.Action](https://developer.android.com/reference/android/arch/persistence/room/ForeignKey.Action)
  - [Ignore](https://developer.android.com/reference/android/arch/persistence/room/Ignore)
  - [Index](https://developer.android.com/reference/android/arch/persistence/room)
  - [Insert](https://developer.android.com/reference/android/arch/persistence/room/Insert)
  - [OnConflictStrategy](https://developer.android.com/reference/android/arch/persistence/room/OnConflictStrategy)
  - [PrimaryKey](https://developer.android.com/reference/android/arch/persistence/room/PrimaryKey)
  - [Query](https://developer.android.com/reference/android/arch/persistence/room/Query)
  - [RawQuery](https://developer.android.com/reference/android/arch/persistence/room/RawQuery)
  - [Relation](https://developer.android.com/reference/android/arch/persistence/room/Relation)
  - [SkipQueryVerification](https://developer.android.com/reference/android/arch/persistence/room/SkipQueryVerification)
  - [Transaction](https://developer.android.com/reference/android/arch/persistence/room/Transaction)
  - [TypeConverter](https://developer.android.com/reference/android/arch/persistence/room/TypeConverter)
  - [TypeConverters](https://developer.android.com/reference/android/arch/persistence/room/TypeConverters)
  - [Update](https://developer.android.com/reference/android/arch/persistence/room/Update)
-

  ## Classes

  - [DatabaseConfiguration](https://developer.android.com/reference/android/arch/persistence/room/DatabaseConfiguration)
  - [InvalidationTracker](https://developer.android.com/reference/android/arch/persistence/room/InvalidationTracker)
  - [InvalidationTracker.Observer](https://developer.android.com/reference/android/arch/persistence/room/InvalidationTracker.Observer)
  - [Room](https://developer.android.com/reference/android/arch/persistence/room/Room)
  - [RoomDatabase](https://developer.android.com/reference/android/arch/persistence/room/RoomDatabase)
  - [RoomDatabase.Builder](https://developer.android.com/reference/android/arch/persistence/room/RoomDatabase.Builder)
  - [RoomDatabase.Callback](https://developer.android.com/reference/android/arch/persistence/room/RoomDatabase.Callback)
  - [RoomDatabase.MigrationContainer](https://developer.android.com/reference/android/arch/persistence/room/RoomDatabase.MigrationContainer)
  - [RoomWarnings](https://developer.android.com/reference/android/arch/persistence/room/RoomWarnings)
  - [RxRoom](https://developer.android.com/reference/android/arch/persistence/room/RxRoom)
-

  ## Enums

  - [RoomDatabase.JournalMode](https://developer.android.com/reference/android/arch/persistence/room/RoomDatabase.JournalMode)
-

  ## Exceptions

  - [EmptyResultSetException](https://developer.android.com/reference/android/arch/persistence/room/EmptyResultSetException)