com.github.dm.jrt.util

Class ClassToken<TYPE>

java.lang.Object

com.github.dm.jrt.util.ClassToken<TYPE>

Type Parameters:

TYPE - the class type.

public abstract class ClassToken<TYPE>
extends Object

Utility abstract class used to work around Java type erasure.

By using class objects it is impossible to distinguish between two different generic classes. For example there is no way to declare a Class<List<String>> as opposed to Class<List<Integer>>.
The workaround consists in forcing the inheritance from a special generic class, then inspected via reflection, to obtain the generic type rather than the class object.

Remember that, in order for the work around to properly work at run time, you will need to add the following rule to your Proguard file (if employing it for shrinking or obfuscation):

     

         -keepattributes Signature
     
 

Created by davide-maestroni on 06/14/2014.

Constructor Summary

Constructors

Constructor and Description
ClassToken()

Method Summary

Methods

Modifier and Type	Method and Description
TYPE	cast(Object object) Casts the specified object to this token type.
boolean	equals(Object o)
Type	getGenericType() Gets the generic type of this token.
Class<TYPE>	getRawClass() Gets the raw class of this token.
int	hashCode()
boolean	isAssignableFrom(ClassToken<?> other) Checks if this token raw class is equal to or is a superclass of the specified one.
boolean	isInterface() Checks if this token raw class represents an interface.
static <TYPE> ClassToken<TYPE>	tokenOf(Class<TYPE> rawClass) Creates a new token from the specified raw class.
static <TYPE> ClassToken<TYPE>	tokenOf(TYPE object) Creates a new token from the class of the specified object.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ClassToken

public ClassToken()

Method Detail

tokenOf

@NotNull
public static <TYPE> ClassToken<TYPE> tokenOf(@NotNull
                                      Class<TYPE> rawClass)

Creates a new token from the specified raw class.

Type Parameters:

TYPE - the class type.

Parameters:

rawClass - the raw class.

Returns:

the newly created token.

tokenOf

@NotNull
public static <TYPE> ClassToken<TYPE> tokenOf(@NotNull
                                      TYPE object)

Creates a new token from the class of the specified object.

Type Parameters:

TYPE - the class type.

Parameters:

object - the object.

Returns:

the newly created token.

cast

public final TYPE cast(Object object)

Casts the specified object to this token type.

Note that the cast is unsafe and may raise an exception.

Parameters:

object - the object to cast.

Returns:

the casted object.

getGenericType

@NotNull
public final Type getGenericType()

Gets the generic type of this token.

Returns:

the generic type.

getRawClass

@NotNull
public final Class<TYPE> getRawClass()

Gets the raw class of this token.

Returns:

the raw class.

Throws:

IllegalStateException - if this class does not correctly extend a class token.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

isAssignableFrom

public final boolean isAssignableFrom(@NotNull
                       ClassToken<?> other)

Checks if this token raw class is equal to or is a superclass of the specified one.

Parameters:

other - the class token to compare.

Returns:

whether this token raw class is equal to or is a superclass.

Throws:

IllegalStateException - if this class does not correctly extend a class token.

isInterface

public final boolean isInterface()

Checks if this token raw class represents an interface.

Returns:

whether this token raw class is an interface.

Throws:

IllegalStateException - if this class does not correctly extend a class token.