org.fujion.common

Class MiscUtil

java.lang.Object

org.fujion.common.MiscUtil

public class MiscUtil
extends Object

Miscellaneous utility methods.

Method Summary

Modifier and Type	Method and Description
static <T,S extends T> List<S>	castList(List<T> list, Class<S> clazz) Casts a list containing elements of class T to a list containing elements of a subclass S.
static boolean	containsInstance(List<?> list, Object object) Returns true if the list contains the exact instance of the specified object.
static boolean	fileExists(String fileName) Returns true if the specified file exists.
static Class<?>[]	getParameterTypes(Object... parameters) Returns an array of parameter types given an array of parameters.
static int	indexOfInstance(List<?> list, Object object) Performs a lookup for the exact instance of an object in the list and returns its index, or -1 if not found.
static <T,S extends T> Iterable<S>	iterableForType(Collection<T> collection, Class<S> type) Returns an iterable that produces only collection members of the specified type.
static <T,S extends T> Iterator<S>	iteratorForType(Collection<T> collection, Class<S> type) Returns a list iterator that produces only collection elements of the specified type.
static <T,S extends T> Iterator<S>	iteratorForType(Iterator<T> iterator, Class<S> type) Returns an iterator that returns only elements of the specified type.
static RuntimeException	toUnchecked(Throwable e) Converts a checked exception to unchecked.

Methods inherited from class java.lang.Object

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

Method Detail

fileExists

public static boolean fileExists(String fileName)

Returns true if the specified file exists.

Parameters:

fileName - File name.

Returns:

True if file exists.

containsInstance

public static boolean containsInstance(List<?> list,
                                       Object object)

Returns true if the list contains the exact instance of the specified object.

Parameters:

list - List to search.

object - Object instance to locate.

Returns:

True if the object was found.

indexOfInstance

public static int indexOfInstance(List<?> list,
                                  Object object)

Performs a lookup for the exact instance of an object in the list and returns its index, or -1 if not found. This is different from the usual implementation of a list search that uses the object's equals implementation.

Parameters:

list - List to search.

object - Object instance to locate.

Returns:

Index of the object.

castList

public static <T,S extends T> List<S> castList(List<T> list,
                                               Class<S> clazz)

Casts a list containing elements of class T to a list containing elements of a subclass S.

Type Parameters:

T - Class of list elements.

S - Target subclass for cast.

Parameters:

list - List to be recast.

clazz - Class to which to cast list elements.

Returns:

The recast list.

iteratorForType

public static <T,S extends T> Iterator<S> iteratorForType(Collection<T> collection,
                                                          Class<S> type)

Returns a list iterator that produces only collection elements of the specified type.

Type Parameters:

T - Class of collection elements.

S - Subclass of T to be used by iterator.

Parameters:

collection - Collection to iterate.

type - Type of element to return.

Returns:

An iterator.

iteratorForType

public static <T,S extends T> Iterator<S> iteratorForType(Iterator<T> iterator,
                                                          Class<S> type)

Returns an iterator that returns only elements of the specified type.

Type Parameters:

T - Class of collection elements.

S - Subclass of T to be used by iterator.

Parameters:

iterator - Iterator to wrap.

type - Type of element to return.

Returns:

An iterator.

iterableForType

public static <T,S extends T> Iterable<S> iterableForType(Collection<T> collection,
                                                          Class<S> type)

Returns an iterable that produces only collection members of the specified type.

Type Parameters:

T - Class of collection elements.

S - Subclass of T to be used by iterable.

Parameters:

collection - Collection to iterate.

type - Type of element to return.

Returns:

An iterable.

toUnchecked

public static RuntimeException toUnchecked(Throwable e)

Converts a checked exception to unchecked. If the original exception is already unchecked, it is simply returned.

Parameters:

e - The original exception.

Returns:

The returned unchecked exception.

getParameterTypes

public static Class<?>[] getParameterTypes(Object... parameters)

Returns an array of parameter types given an array of parameters. Unlike other libraries, this allows null parameter values.

Parameters:

parameters - Array of parameters.

Returns:

Array of parameter types.