# Class UnknownTypeException

java.lang.Object
java.lang.Throwable
java.lang.Exception
java.lang.RuntimeException
javax.lang.model.UnknownEntityException
javax.lang.model.type.UnknownTypeException

All Implemented Interfaces:
  `Serializable`

public class UnknownTypeException extends UnknownEntityException
Indicates that an unknown kind of type was encountered. This can occur if the language evolves and new kinds of types are added to the `TypeMirror` hierarchy. May be thrown by a type visitor to indicate that the visitor was created for a prior version of the language.

Since:
  1.6
See Also:
  - `TypeVisitor.visitUnknown(TypeMirror, P)`
  - Serialized Form

## Constructor Summary

Constructors
Constructor
Description
`UnknownTypeException(TypeMirror t, Object p)`
Creates a new `UnknownTypeException`.The `p` parameter may be used to pass in an additional argument with information about the context in which the unknown type was encountered; for example, the visit methods of `TypeVisitor` may pass in their additional parameter.

## Method Summary

Modifier and Type
Method
Description
`Object`
`getArgument()`
Returns the additional argument.
`TypeMirror`
`getUnknownType()`
Returns the unknown type.

### Methods declared in class Throwable

`addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString`

### Methods declared in class Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

## Constructor Details

### UnknownTypeException

public UnknownTypeException(TypeMirror t, Object p)
Creates a new `UnknownTypeException`.The `p` parameter may be used to pass in an additional argument with information about the context in which the unknown type was encountered; for example, the visit methods of `TypeVisitor` may pass in their additional parameter.

Parameters:
  `t` - the unknown type, may be `null`
  `p` - an additional parameter, may be `null`

## Method Details

### getUnknownType

public TypeMirror getUnknownType()
Returns the unknown type. The value may be unavailable if this exception has been serialized and then read back in.

Returns:
  the unknown type, or `null` if unavailable

### getArgument

public Object getArgument()
Returns the additional argument.

Returns:
  the additional argument, or `null` if unavailable