Assertions (ExoPlayer library)

java.lang.Object
- com.google.android.exoplayer2.util.Assertions

```
public final class Assertions
extends Object
```
Provides methods for asserting the truth of expressions and properties.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`checkArgument(boolean expression)`	Throws `IllegalArgumentException` if `expression` evaluates to false.
`static void`	`checkArgument(boolean expression, Object errorMessage)`	Throws `IllegalArgumentException` if `expression` evaluates to false.
`static int`	`checkIndex(int index, int start, int limit)`	Throws `IndexOutOfBoundsException` if `index` falls outside the specified bounds.
`static void`	`checkMainThread()`	Throws `IllegalStateException` if the calling thread is not the application's main thread.
`static String`	`checkNotEmpty(String string)`	Throws `IllegalArgumentException` if `string` is null or zero length.
`static String`	`checkNotEmpty(String string, Object errorMessage)`	Throws `IllegalArgumentException` if `string` is null or zero length.
`static <T> T`	`checkNotNull(T reference)`	Throws `NullPointerException` if `reference` is null.
`static <T> T`	`checkNotNull(T reference, Object errorMessage)`	Throws `NullPointerException` if `reference` is null.
`static void`	`checkState(boolean expression)`	Throws `IllegalStateException` if `expression` evaluates to false.
`static void`	`checkState(boolean expression, Object errorMessage)`	Throws `IllegalStateException` if `expression` evaluates to false.
`static <T> T`	`checkStateNotNull(T reference)`	Throws `IllegalStateException` if `reference` is null.
`static <T> T`	`checkStateNotNull(T reference, Object errorMessage)`	Throws `IllegalStateException` if `reference` is null.

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

- Method Detail
  - checkArgument
```
@Pure
public static void checkArgument(boolean expression)
```
    Throws IllegalArgumentException if expression evaluates to false.
    
    Parameters:
    
    expression - The expression to evaluate.
    
    Throws:
    
    IllegalArgumentException - If expression is false.
  - checkArgument
```
@Pure
public static void checkArgument(boolean expression,
                                 Object errorMessage)
```
    Throws IllegalArgumentException if expression evaluates to false.
    
    Parameters:
    
    expression - The expression to evaluate.
    
    errorMessage - The exception message if an exception is thrown. The message is converted to a String using String.valueOf(Object).
    
    Throws:
    
    IllegalArgumentException - If expression is false.
  - checkIndex
```
@Pure
public static int checkIndex(int index,
                             int start,
                             int limit)
```
    Throws IndexOutOfBoundsException if index falls outside the specified bounds.
    
    Parameters:
    
    index - The index to test.
    
    start - The start of the allowed range (inclusive).
    
    limit - The end of the allowed range (exclusive).
    
    Returns:
    
    The index that was validated.
    
    Throws:
    
    IndexOutOfBoundsException - If index falls outside the specified bounds.
  - checkState
```
@Pure
public static void checkState(boolean expression)
```
    Throws IllegalStateException if expression evaluates to false.
    
    Parameters:
    
    expression - The expression to evaluate.
    
    Throws:
    
    IllegalStateException - If expression is false.
  - checkState
```
@Pure
public static void checkState(boolean expression,
                              Object errorMessage)
```
    Throws IllegalStateException if expression evaluates to false.
    
    Parameters:
    
    expression - The expression to evaluate.
    
    errorMessage - The exception message if an exception is thrown. The message is converted to a String using String.valueOf(Object).
    
    Throws:
    
    IllegalStateException - If expression is false.
  - checkStateNotNull
```
@EnsuresNonNull("#1")
@Pure
public static <T> T checkStateNotNull(@Nullable
                                      T reference)
```
    Throws IllegalStateException if reference is null.
    
    Type Parameters:
    
    T - The type of the reference.
    
    Parameters:
    
    reference - The reference.
    
    Returns:
    
    The non-null reference that was validated.
    
    Throws:
    
    IllegalStateException - If reference is null.
  - checkStateNotNull
```
@EnsuresNonNull("#1")
@Pure
public static <T> T checkStateNotNull(@Nullable
                                      T reference,
                                      Object errorMessage)
```
    Throws IllegalStateException if reference is null.
    
    Type Parameters:
    
    T - The type of the reference.
    
    Parameters:
    
    reference - The reference.
    
    errorMessage - The exception message to use if the check fails. The message is converted to a string using String.valueOf(Object).
    
    Returns:
    
    The non-null reference that was validated.
    
    Throws:
    
    IllegalStateException - If reference is null.
  - checkNotNull
```
@EnsuresNonNull("#1")
@Pure
public static <T> T checkNotNull(@Nullable
                                 T reference)
```
    Throws NullPointerException if reference is null.
    
    Type Parameters:
    
    T - The type of the reference.
    
    Parameters:
    
    reference - The reference.
    
    Returns:
    
    The non-null reference that was validated.
    
    Throws:
    
    NullPointerException - If reference is null.
  - checkNotNull
```
@EnsuresNonNull("#1")
@Pure
public static <T> T checkNotNull(@Nullable
                                 T reference,
                                 Object errorMessage)
```
    Throws NullPointerException if reference is null.
    
    Type Parameters:
    
    T - The type of the reference.
    
    Parameters:
    
    reference - The reference.
    
    errorMessage - The exception message to use if the check fails. The message is converted to a string using String.valueOf(Object).
    
    Returns:
    
    The non-null reference that was validated.
    
    Throws:
    
    NullPointerException - If reference is null.
  - checkNotEmpty
```
@EnsuresNonNull("#1")
@Pure
public static String checkNotEmpty(@Nullable
                                   String string)
```
    Throws IllegalArgumentException if string is null or zero length.
    
    Parameters:
    
    string - The string to check.
    
    Returns:
    
    The non-null, non-empty string that was validated.
    
    Throws:
    
    IllegalArgumentException - If string is null or 0-length.
  - checkNotEmpty
```
@EnsuresNonNull("#1")
@Pure
public static String checkNotEmpty(@Nullable
                                   String string,
                                   Object errorMessage)
```
    Throws IllegalArgumentException if string is null or zero length.
    
    Parameters:
    
    string - The string to check.
    
    errorMessage - The exception message to use if the check fails. The message is converted to a string using String.valueOf(Object).
    
    Returns:
    
    The non-null, non-empty string that was validated.
    
    Throws:
    
    IllegalArgumentException - If string is null or 0-length.
  - checkMainThread
```
@Pure
public static void checkMainThread()
```
    Throws IllegalStateException if the calling thread is not the application's main thread.
    
    Throws:
    
    IllegalStateException - If the calling thread is not the application's main thread.

Class Assertions

Method Summary

Methods inherited from class java.lang.Object

Method Detail

checkArgument

checkArgument

checkIndex

checkState

checkState

checkStateNotNull

checkStateNotNull

checkNotNull

checkNotNull

checkNotEmpty

checkNotEmpty

checkMainThread