Nested Classes
Modifier and Type	Class	Description
`protected static class`	`Extension.ExtensionType`	The API type that the extension is used for.
`static class`	`Extension.MessageType`	Type of a message extension.

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`protected abstract java.lang.Object`	`fromReflectionType(java.lang.Object value)`
`abstract Type`	`getDefaultValue()`	Returns the default value of the extension field.
`abstract Descriptors.FieldDescriptor`	`getDescriptor()`	Returns the descriptor of the extension.
`protected Extension.ExtensionType`	`getExtensionType()`
`abstract WireFormat.FieldType`	`getLiteType()`	Returns the type of the field.
`abstract MessageLite`	`getMessageDefaultInstance()`	Returns the default instance of the extension field, if it's a message extension.
`Extension.MessageType`	`getMessageType()`	If the extension is a message extension (i.e., getLiteType() == MESSAGE), returns the type of the message, otherwise undefined.
`abstract int`	`getNumber()`	Returns the field number of the extension.
`abstract boolean`	`isRepeated()`	Returns whether it is a repeated field.
`protected abstract java.lang.Object`	`singularFromReflectionType(java.lang.Object value)`
`protected abstract java.lang.Object`	`singularToReflectionType(java.lang.Object value)`
`protected abstract java.lang.Object`	`toReflectionType(java.lang.Object value)`

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

getNumber
```
public abstract int getNumber()
```
Returns the field number of the extension.

public abstract WireFormat.FieldType getLiteType()

Returns the type of the field.

isRepeated
```
public abstract boolean isRepeated()
```
Returns whether it is a repeated field.

public abstract Descriptors.FieldDescriptor getDescriptor()

Returns the descriptor of the extension.

getDefaultValue
```
public abstract Type getDefaultValue()
```
Returns the default value of the extension field.

getMessageDefaultInstance
```
public abstract MessageLite getMessageDefaultInstance()
```
Returns the default instance of the extension field, if it's a message extension.

protected Extension.ExtensionType getExtensionType()

getMessageType
```
public Extension.MessageType getMessageType()
```
If the extension is a message extension (i.e., getLiteType() == MESSAGE), returns the type of the message, otherwise undefined.

protected abstract java.lang.Object fromReflectionType(java.lang.Object value)

protected abstract java.lang.Object singularFromReflectionType(java.lang.Object value)

protected abstract java.lang.Object toReflectionType(java.lang.Object value)

protected abstract java.lang.Object singularToReflectionType(java.lang.Object value)

Class Extension<ContainingType extends MessageLite,​Type>

Class Extension<ContainingType extends MessageLite,Type>