org.fastnate.util

Class ClassUtil

java.lang.Object

org.fastnate.util.ClassUtil

public final class ClassUtil
extends Object

Helper for inspection of classes.

Author:

Tobias Liefke

Field Summary

Fields

Modifier and Type	Field and Description
private static Map<Class<? extends Number>,Function<Number,Number>>	NUMBER_MAPPERS Mapping from a number class to its mapping function.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ClassUtil()

Method Summary

Modifier and Type	Method and Description
static <N extends Number> N	convertNumber(Number number, Class<N> targetType) Tries to convert the given number to the given type.
private static <I> Type	getActualTypeArgument(Class<? extends I> instanceClass, Class<I> superClass, int argumentIndex)
static <T,I> Class<T>	getActualTypeBinding(Class<? extends I> instanceClass, Class<I> superClass, int argumentIndex) Resolves the actual binding of a generic type that was specified in a superclass and bound in a subclass.
static <T,I> Class<T>	getActualTypeBinding(Class<? extends I> instanceClass, Class<I> declaringClass, Type attributeType) Resolves the actual binding of a generic type to a specific class by inspecting type variables in the declaring class and the (sub)class of the object.
static String	getCallerMethod() Resolves the name of the method that called the caller of this method.
static String	getCallerMethod(Class<?> callerClass) Resolves the name of the method that called the caller of this method.

Methods inherited from class java.lang.Object

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

Field Detail

NUMBER_MAPPERS

private static final Map<Class<? extends Number>,Function<Number,Number>> NUMBER_MAPPERS

Mapping from a number class to its mapping function.

Constructor Detail

ClassUtil

private ClassUtil()

Method Detail

convertNumber

public static <N extends Number> N convertNumber(Number number,
                                                 Class<N> targetType)

Tries to convert the given number to the given type.

Parameters:

number - the number that we have

targetType - the type that we need

Returns:

the number in the given type

Throws:

IllegalArgumentException - if the target type is not a common number type

getActualTypeArgument

private static <I> Type getActualTypeArgument(Class<? extends I> instanceClass,
                                              Class<I> superClass,
                                              int argumentIndex)

getActualTypeBinding

public static <T,I> Class<T> getActualTypeBinding(Class<? extends I> instanceClass,
                                                  Class<I> superClass,
                                                  int argumentIndex)

Resolves the actual binding of a generic type that was specified in a superclass and bound in a subclass.

Parameters:

instanceClass - the implementing class

superClass - the superclass or interface which specifies the generic type variable

argumentIndex - the index of the type variable in the superclass definition (0 = the first type variable)

Returns:

the bound class for the variable in instanceClass

getActualTypeBinding

public static <T,I> Class<T> getActualTypeBinding(Class<? extends I> instanceClass,
                                                  Class<I> declaringClass,
                                                  Type attributeType)

Resolves the actual binding of a generic type to a specific class by inspecting type variables in the declaring class and the (sub)class of the object.

Parameters:

instanceClass - the class that implements the object and may contain the binding of the type parameters

declaringClass - the class that declared the attribute

attributeType - the return type, parameter type or field type of the attribute that may contain references to type parameters

Returns:

the qualified type of the attribute according to the instance class

getCallerMethod

public static String getCallerMethod()

Resolves the name of the method that called the caller of this method.

Returns:

the name of the caller

getCallerMethod

public static String getCallerMethod(Class<?> callerClass)

Resolves the name of the method that called the caller of this method. Steps up until the caller belongs to the given class

Parameters:

callerClass - the class that the method belongs to

Returns:

the name of the caller