gate.util
Class Tools

java.lang.Object
  gate.util.Tools

public class Tools
extends Object

Constructor Summary

Tools()

Method Summary

static List	findSubclasses(Class parentClass) Finds all subclasses of a given class or interface.
static Long	gensym() Returns a Long wich is unique during the current run.
static Long	genTime()
static Constructor	getMostSpecificConstructor(Class targetClass, Class paramClass) Find the constructor to use to create an instance of targetClass from one of paramClass.
static boolean	isUnicodeEnabled() Checks wheter Gate is Unicode enabled
static void	printStackTrace(PrintStream pStream) Prints the stack trace of the current thread to the specified print stream.
static void	setUnicodeEnabled(boolean value) Specifies whether Gate should or shouldn't know about Unicode

Methods inherited from class java.lang.Object

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

Constructor Detail

Tools

public Tools()

Method Detail

gensym

public static Long gensym()

Returns a Long wich is unique during the current run. Maybe we should use serializaton in order to save the state on System.exit...

genTime

public static Long genTime()

setUnicodeEnabled

public static void setUnicodeEnabled(boolean value)

Specifies whether Gate should or shouldn't know about Unicode

isUnicodeEnabled

public static boolean isUnicodeEnabled()

Checks wheter Gate is Unicode enabled

findSubclasses

public static List findSubclasses(Class parentClass)

Finds all subclasses of a given class or interface. It will only search within the loaded packages and not the entire classpath.

Parameters:

parentClass - the class for which subclasses are sought

Returns:

a list of Class objects.

getMostSpecificConstructor

public static Constructor getMostSpecificConstructor(Class targetClass,
                                                     Class paramClass)
                                              throws NoSuchMethodException

Find the constructor to use to create an instance of targetClass from one of paramClass. We use the same rules as Java in finding the constructor to call, i.e. we find the constructor that javac would call for the expression parameterValue = new PropertyType(parameterValue):

1. find all the single-argument constructors for propertyType whose argument type T1 is assignable from paramType
2. from these, choose the one whose argument type T2 is more specific than the argument type S of every other one i.e. for all S, S.isAssignableFrom(T2)

If there is no applicable single argument constructor that is more specific than all the others, then the above expression would be a compile error (constructor ParamType(X) is ambiguous).

(The "most specific" check is to catch situations such as paramClass implements SortedSet, targetClass = TreeSet. Here both TreeSet(SortedSet) and TreeSet(Collection) are applicable but the former is more specific. However, if paramType also implements Comparator then there are three applicable constructors, taking SortedSet, Collection and Comparator respectively and none of these types is assignable to both the others. This is ambiguous according to the Java Language Specification, 2nd edition, section 15.12.2)

Parameters:

targetClass - the class we wish to construct

paramClass - the type of the object to pass as a parameter to the constructor.

Returns:

the most specific constructor of targetClass that is applicable to an argument of paramClass

Throws:

NoSuchMethodException - if there are no applicable constructors, or if there is no single most-specific one.

printStackTrace

public static final void printStackTrace(PrintStream pStream)

Prints the stack trace of the current thread to the specified print stream.

Parameters:

pStream -