# Assertions

Artifact: [androidx.media3:media3-common](https://developer.android.com/jetpack/androidx/releases/media3) [View Source](https://cs.android.com/search?q=file:androidx/media3/common/util/Assertions.java+class:androidx.media3.common.util.Assertions)

*** ** * ** ***


```
@UnstableApi
class Assertions
```

<br />

*** ** * ** ***

Provides methods for asserting the truth of expressions and properties.

## Summary

| ### Public functions |
|---|---|
| `java-static https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-unit/index.html` | `@https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html @https://checkerframework.org/api/com/google/errorprone/annotations/InlineMe.html(replacement = "Preconditions.checkArgument(expression)", imports = "com.google.common.base.Preconditions") [checkArgument](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkArgument(boolean))(expression: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-boolean/index.html)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkArgument(boolean)` instead. <br /> |
| `java-static https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-unit/index.html` | `@https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html @https://checkerframework.org/api/com/google/errorprone/annotations/InlineMe.html(replacement = "Preconditions.checkArgument(expression, errorMessage)", imports = "com.google.common.base.Preconditions") [checkArgument](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkArgument(boolean,java.lang.Object))(expression: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-boolean/index.html, errorMessage: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-any/index.html!)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkArgument(boolean)` instead. <br /> |
| `java-static https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-int/index.html` | `@https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html [checkIndex](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkIndex(int,int,int))(index: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-int/index.html, start: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-int/index.html, limit: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-int/index.html)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkElementIndex(int, int)`, with an additional assertion to check a non-zero `start` value if needed. <br /> |
| `java-static https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-unit/index.html` | `@https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html @https://checkerframework.org/api/com/google/errorprone/annotations/InlineMe.html(replacement = "Preconditions.checkState(Looper.myLooper() == Looper.getMainLooper(), \"Not in" + " application's main thread\")", imports = [""com.google.common.base.Preconditions"", ""android.os.Looper""]) [checkMainThread](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkMainThread())()` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkState(boolean)` to assert `Looper.myLooper() == Looper.getMainLooper()` instead. <br /> |
| `java-static https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-string/index.html!` | `@https://checkerframework.org/api/org/checkerframework/checker/nullness/qual/EnsuresNonNull.html(value = [""#1""]) @https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html [checkNotEmpty](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkNotEmpty(java.lang.String))(string: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-string/index.html?)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkArgument(boolean)` with `https://developer.android.com/reference/android/text/TextUtils.html#isEmpty(java.lang.CharSequence)` instead. <br /> |
| `java-static https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-string/index.html!` | `@https://checkerframework.org/api/org/checkerframework/checker/nullness/qual/EnsuresNonNull.html(value = [""#1""]) @https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html [checkNotEmpty](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkNotEmpty(java.lang.String,java.lang.Object))(string: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-string/index.html?, errorMessage: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-any/index.html!)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkArgument(boolean)` with `https://developer.android.com/reference/android/text/TextUtils.html#isEmpty(java.lang.CharSequence)` instead. <br /> |
| `java-static T!` | `@https://checkerframework.org/api/org/checkerframework/checker/nullness/qual/EnsuresNonNull.html(value = [""#1""]) @https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html @https://checkerframework.org/api/com/google/errorprone/annotations/InlineMe.html(replacement = "Preconditions.checkNotNull(reference)", imports = "com.google.common.base.Preconditions") <T> [checkNotNull](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkNotNull(T))(reference: T?)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkNotNull(T)` instead. <br /> |
| `java-static T!` | `@https://checkerframework.org/api/org/checkerframework/checker/nullness/qual/EnsuresNonNull.html(value = [""#1""]) @https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html @https://checkerframework.org/api/com/google/errorprone/annotations/InlineMe.html(replacement = "Preconditions.checkNotNull(reference, errorMessage)", imports = "com.google.common.base.Preconditions") <T> [checkNotNull](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkNotNull(T,java.lang.Object))(reference: T?, errorMessage: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-any/index.html!)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkNotNull(T)` instead. <br /> |
| `java-static https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-unit/index.html` | `@https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html @https://checkerframework.org/api/com/google/errorprone/annotations/InlineMe.html(replacement = "Preconditions.checkState(expression)", imports = "com.google.common.base.Preconditions") [checkState](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkState(boolean))(expression: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-boolean/index.html)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkState(boolean)` instead. <br /> |
| `java-static https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-unit/index.html` | `@https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html @https://checkerframework.org/api/com/google/errorprone/annotations/InlineMe.html(replacement = "Preconditions.checkState(expression, errorMessage)", imports = "com.google.common.base.Preconditions") [checkState](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkState(boolean,java.lang.Object))(expression: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-boolean/index.html, errorMessage: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-any/index.html!)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkState(boolean)` instead. <br /> |
| `java-static T!` | `@https://checkerframework.org/api/org/checkerframework/checker/nullness/qual/EnsuresNonNull.html(value = [""#1""]) @https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html @https://checkerframework.org/api/com/google/errorprone/annotations/InlineMe.html(replacement = "Preconditions.checkNotNull(reference)", imports = "com.google.common.base.Preconditions") <T> [checkStateNotNull](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkStateNotNull(T))(reference: T?)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkNotNull(T)` instead. <br /> |
| `java-static T!` | `@https://checkerframework.org/api/org/checkerframework/checker/nullness/qual/EnsuresNonNull.html(value = [""#1""]) @https://checkerframework.org/api/org/checkerframework/dataflow/qual/Pure.html @https://checkerframework.org/api/com/google/errorprone/annotations/InlineMe.html(replacement = "Preconditions.checkNotNull(reference, errorMessage)", imports = "com.google.common.base.Preconditions") <T> [checkStateNotNull](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkStateNotNull(T,java.lang.Object))(reference: T?, errorMessage: https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-any/index.html!)` **This function is deprecated.** Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkNotNull(T)` instead. <br /> |

## Public functions

### checkArgument

```
@Pure
@InlineMe(replacement = "Preconditions.checkArgument(expression)", imports = "com.google.common.base.Preconditions")
java-static fun [checkArgument](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkArgument(boolean))(expression: Boolean): Unit
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkArgument(boolean)` instead.

### checkArgument

```
@Pure
@InlineMe(replacement = "Preconditions.checkArgument(expression, errorMessage)", imports = "com.google.common.base.Preconditions")
java-static fun [checkArgument](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkArgument(boolean,java.lang.Object))(expression: Boolean, errorMessage: Any!): Unit
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkArgument(boolean)` instead.

### checkIndex

```
@Pure
java-static fun [checkIndex](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkIndex(int,int,int))(index: Int, start: Int, limit: Int): Int
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkElementIndex(int, int)`, with an additional assertion to check a non-zero `start` value if needed.

### checkMainThread

```
@Pure
@InlineMe(replacement = "Preconditions.checkState(Looper.myLooper() == Looper.getMainLooper(), \"Not in"
              + " application's main thread\")", imports = [""com.google.common.base.Preconditions"", ""android.os.Looper""])
java-static fun [checkMainThread](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkMainThread())(): Unit
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkState(boolean)` to assert `Looper.myLooper() ==
> Looper.getMainLooper()` instead.

### checkNotEmpty

```
@EnsuresNonNull(value = [""#1""])
@Pure
java-static fun [checkNotEmpty](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkNotEmpty(java.lang.String))(string: String?): String!
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkArgument(boolean)` with `https://developer.android.com/reference/android/text/TextUtils.html#isEmpty(java.lang.CharSequence)` instead.

### checkNotEmpty

```
@EnsuresNonNull(value = [""#1""])
@Pure
java-static fun [checkNotEmpty](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkNotEmpty(java.lang.String,java.lang.Object))(string: String?, errorMessage: Any!): String!
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkArgument(boolean)` with `https://developer.android.com/reference/android/text/TextUtils.html#isEmpty(java.lang.CharSequence)` instead.

### checkNotNull

```
@EnsuresNonNull(value = [""#1""])
@Pure
@InlineMe(replacement = "Preconditions.checkNotNull(reference)", imports = "com.google.common.base.Preconditions")
java-static fun <T> [checkNotNull](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkNotNull(T))(reference: T?): T!
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkNotNull(T)` instead.

### checkNotNull

```
@EnsuresNonNull(value = [""#1""])
@Pure
@InlineMe(replacement = "Preconditions.checkNotNull(reference, errorMessage)", imports = "com.google.common.base.Preconditions")
java-static fun <T> [checkNotNull](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkNotNull(T,java.lang.Object))(reference: T?, errorMessage: Any!): T!
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkNotNull(T)` instead.

### checkState

```
@Pure
@InlineMe(replacement = "Preconditions.checkState(expression)", imports = "com.google.common.base.Preconditions")
java-static fun [checkState](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkState(boolean))(expression: Boolean): Unit
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkState(boolean)` instead.

### checkState

```
@Pure
@InlineMe(replacement = "Preconditions.checkState(expression, errorMessage)", imports = "com.google.common.base.Preconditions")
java-static fun [checkState](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkState(boolean,java.lang.Object))(expression: Boolean, errorMessage: Any!): Unit
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkState(boolean)` instead.

### checkStateNotNull

```
@EnsuresNonNull(value = [""#1""])
@Pure
@InlineMe(replacement = "Preconditions.checkNotNull(reference)", imports = "com.google.common.base.Preconditions")
java-static fun <T> [checkStateNotNull](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkStateNotNull(T))(reference: T?): T!
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkNotNull(T)` instead.

### checkStateNotNull

```
@EnsuresNonNull(value = [""#1""])
@Pure
@InlineMe(replacement = "Preconditions.checkNotNull(reference, errorMessage)", imports = "com.google.common.base.Preconditions")
java-static fun <T> [checkStateNotNull](https://developer.android.com/reference/kotlin/androidx/media3/common/util/Assertions#checkStateNotNull(T,java.lang.Object))(reference: T?, errorMessage: Any!): T!
```

> [!CAUTION]
> **This function is deprecated.**   
>
> Use `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/base/Preconditions.html#checkNotNull(T)` instead.