Added in [API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Fields](https://developer.android.com/reference/android/system/ErrnoException#lfields) \| [Ctors](https://developer.android.com/reference/android/system/ErrnoException#pubctors) \| [Methods](https://developer.android.com/reference/android/system/ErrnoException#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/android/system/ErrnoException#inhmethods)

# ErrnoException

*** ** * ** ***

` public final class ErrnoException `   
` ` ` ` ` extends https://developer.android.com/reference/java/lang/Exception ` ` `

|---|---|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||||
| ↳ | [java.lang.Throwable](https://developer.android.com/reference/java/lang/Throwable) |||
|   | ↳ | [java.lang.Exception](https://developer.android.com/reference/java/lang/Exception) ||
|   |   | ↳ | android.system.ErrnoException |

<br />

*** ** * ** ***

A checked exception thrown when `https://developer.android.com/reference/android/system/Os` methods fail. This exception contains the native errno value, for comparison against the constants in `https://developer.android.com/reference/android/system/OsConstants`, should sophisticated callers need to adjust their behavior based on the exact failure.

## Summary

| ### Fields ||
|---|---|
| ` public final int` | `https://developer.android.com/reference/android/system/ErrnoException#errno` The errno value, for comparison with the `E` constants in `https://developer.android.com/reference/android/system/OsConstants`. |

| ### Public constructors ||
|---|---|
| ` https://developer.android.com/reference/android/system/ErrnoException#ErrnoException(java.lang.String,%20int)(https://developer.android.com/reference/java/lang/String functionName, int errno) ` Constructs an instance with the given function name and errno value. |
| ` https://developer.android.com/reference/android/system/ErrnoException#ErrnoException(java.lang.String,%20int,%20java.lang.Throwable)(https://developer.android.com/reference/java/lang/String functionName, int errno, https://developer.android.com/reference/java/lang/Throwable cause) ` Constructs an instance with the given function name, errno value, and cause. |

| ### Public methods ||
|---|---|
| ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/android/system/ErrnoException#getMessage()() ` Converts the stashed function name and errno value to a human-readable string. |
| ` https://developer.android.com/reference/java/io/IOException` | ` https://developer.android.com/reference/android/system/ErrnoException#rethrowAsIOException()() ` Throws an `https://developer.android.com/reference/java/io/IOException` with a message based on `https://developer.android.com/reference/android/system/ErrnoException#getMessage()` and with this instance as the cause. |
| ` https://developer.android.com/reference/java/net/SocketException` | ` https://developer.android.com/reference/android/system/ErrnoException#rethrowAsSocketException()() ` Throws a `https://developer.android.com/reference/java/net/SocketException` with a message based on `https://developer.android.com/reference/android/system/ErrnoException#getMessage()` and with this instance as the cause. |

### Inherited methods

From class ` https://developer.android.com/reference/java/lang/Throwable ` ` final void` ` https://developer.android.com/reference/java/lang/Throwable#addSuppressed(java.lang.Throwable)(https://developer.android.com/reference/java/lang/Throwable exception) `

Appends the specified exception to the exceptions that were suppressed in order to deliver this exception.
` https://developer.android.com/reference/java/lang/Throwable` ` https://developer.android.com/reference/java/lang/Throwable#fillInStackTrace()() `

Fills in the execution stack trace.
` https://developer.android.com/reference/java/lang/Throwable` ` https://developer.android.com/reference/java/lang/Throwable#getCause()() `

Returns the cause of this throwable or `null` if the cause is nonexistent or unknown.
` https://developer.android.com/reference/java/lang/String` ` https://developer.android.com/reference/java/lang/Throwable#getLocalizedMessage()() `

Creates a localized description of this throwable.
` https://developer.android.com/reference/java/lang/String` ` https://developer.android.com/reference/java/lang/Throwable#getMessage()() `

Returns the detail message string of this throwable.
` https://developer.android.com/reference/java/lang/StackTraceElement` ` https://developer.android.com/reference/java/lang/Throwable#getStackTrace()() `

Provides programmatic access to the stack trace information printed by `https://developer.android.com/reference/java/lang/Throwable#printStackTrace()`.
` final https://developer.android.com/reference/java/lang/Throwable` ` https://developer.android.com/reference/java/lang/Throwable#getSuppressed()() `

Returns an array containing all of the exceptions that were suppressed, typically by the `try`-with-resources statement, in order to deliver this exception.
` https://developer.android.com/reference/java/lang/Throwable` ` https://developer.android.com/reference/java/lang/Throwable#initCause(java.lang.Throwable)(https://developer.android.com/reference/java/lang/Throwable cause) `

Initializes the *cause* of this throwable to the specified value.
` void` ` https://developer.android.com/reference/java/lang/Throwable#printStackTrace()() `

Prints this throwable and its backtrace to the standard error stream.
` void` ` https://developer.android.com/reference/java/lang/Throwable#printStackTrace(java.io.PrintWriter)(https://developer.android.com/reference/java/io/PrintWriter s) `

Prints this throwable and its backtrace to the specified print writer.
` void` ` https://developer.android.com/reference/java/lang/Throwable#printStackTrace(java.io.PrintStream)(https://developer.android.com/reference/java/io/PrintStream s) `

Prints this throwable and its backtrace to the specified print stream.
` void` ` https://developer.android.com/reference/java/lang/Throwable#setStackTrace(java.lang.StackTraceElement[])(https://developer.android.com/reference/java/lang/StackTraceElement stackTrace) `

Sets the stack trace elements that will be returned by `https://developer.android.com/reference/java/lang/Throwable#getStackTrace()` and printed by `https://developer.android.com/reference/java/lang/Throwable#printStackTrace()` and related methods.
` https://developer.android.com/reference/java/lang/String` ` https://developer.android.com/reference/java/lang/Throwable#toString()() `

Returns a short description of this throwable.
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*.

## Fields

### errno

Added in [API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public final int errno
```

The errno value, for comparison with the `E` constants in `https://developer.android.com/reference/android/system/OsConstants`.

<br />

## Public constructors

### ErrnoException

Added in [API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public ErrnoException (String functionName, 
                int errno)
```

Constructs an instance with the given function name and errno value.

<br />

| Parameters ||
|---|---|
| `functionName` | `String` <br /> |
| `errno` | `int` <br /> |

### ErrnoException

Added in [API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public ErrnoException (String functionName, 
                int errno, 
                Throwable cause)
```

Constructs an instance with the given function name, errno value, and cause.

<br />

| Parameters ||
|---|---|
| `functionName` | `String` <br /> |
| `errno` | `int` <br /> |
| `cause` | `Throwable` <br /> |

## Public methods

### getMessage

Added in [API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public String getMessage ()
```

Converts the stashed function name and errno value to a human-readable string. We do this here rather than in the constructor so that callers only pay for this if they need it.

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/String` | the detail message string of this `Throwable` instance (which may be `null`). <br /> |

### rethrowAsIOException

Added in [API level 30](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public IOException rethrowAsIOException ()
```

Throws an `https://developer.android.com/reference/java/io/IOException` with a message based on `https://developer.android.com/reference/android/system/ErrnoException#getMessage()` and with this instance as the cause.

This method always terminates by throwing the exception. Callers can write `throw e.rethrowAsIOException()` to make that clear to the compiler.

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | This value cannot be `null`. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` |   |

### rethrowAsSocketException

Added in [API level 30](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public SocketException rethrowAsSocketException ()
```

Throws a `https://developer.android.com/reference/java/net/SocketException` with a message based on `https://developer.android.com/reference/android/system/ErrnoException#getMessage()` and with this instance as the cause.

This method always terminates by throwing the exception. Callers can write `throw e.rethrowAsIOException()` to make that clear to the compiler.

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/net/SocketException` | This value cannot be `null`. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/net/SocketException` |   |