org.lenskit.util

Class TypeUtils

java.lang.Object

org.lenskit.util.TypeUtils

public class TypeUtils
extends java.lang.Object

Various type utilities used in LensKit.

Method Summary

Modifier and Type	Method and Description
static <T> TypeToken<T>	listElementType(TypeToken<? extends java.util.List<T>> token) Extract the element type from a type token representing a list.
static <T> org.joda.convert.FromStringConverter<T>	lookupFromStringConverter(TypeToken<T> type) Look up a converter to convert strings to the specified type.
static <T> TypeToken<java.util.List<T>>	makeListType(TypeToken<T> element) Make a type token for a list of a particular element type.
static <T> java.lang.String	makeTypeName(TypeToken<T> type) Turn a type token into a parsable type name.
static TypeToken<?>	resolveTypeName(java.lang.String type) Resolve a type name into a type.
static java.util.Set<java.lang.Class<?>>	typeClosure(java.lang.Class<?> type) Return the supertype closure of a type (the type and all its transitive supertypes).

Methods inherited from class java.lang.Object

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

Method Detail

typeClosure

public static java.util.Set<java.lang.Class<?>> typeClosure(java.lang.Class<?> type)

Return the supertype closure of a type (the type and all its transitive supertypes).

Parameters:

type - The type.

Returns:

All supertypes of the type, including the type itself.

makeListType

public static <T> TypeToken<java.util.List<T>> makeListType(TypeToken<T> element)

Make a type token for a list of a particular element type.

Parameters:

element - The element type.

T - The element type.

Returns:

A type token representing List<T>.

listElementType

public static <T> TypeToken<T> listElementType(TypeToken<? extends java.util.List<T>> token)

Extract the element type from a type token representing a list.

Parameters:

token - The type token.

T - The list element type.

Returns:

The type token for the list’s element type.

resolveTypeName

public static TypeToken<?> resolveTypeName(java.lang.String type)

Resolve a type name into a type. This is like class lookup with a few additions:

• Aliases for common types (string, int, long, double)
• Lists are handled with an array syntax (string[] becomes List<String>)

Parameters:

type - The type name to resolve.

Returns:

The type.

makeTypeName

public static <T> java.lang.String makeTypeName(TypeToken<T> type)

Turn a type token into a parsable type name.

Parameters:

type - The type token.

T - The type.

Returns:

A string that can be parsed by resolveTypeName(String).

lookupFromStringConverter

public static <T> org.joda.convert.FromStringConverter<T> lookupFromStringConverter(TypeToken<T> type)

Look up a converter to convert strings to the specified type. List types are converted from comma-separated values.

Parameters:

type - The type.

T - The type.

Returns:

A converter to parse objects of type type from strings.