WildcardTypeImpl.java

/*
 * Copied from Gentyref project http://code.google.com/p/gentyref/
 * Reformatted and moved to fit package structure
 */
package com.google.sitebricks.conversion.generics;

import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import java.util.Arrays;

class WildcardTypeImpl implements WildcardType
{
	private final Type[] upperBounds;
	private final Type[] lowerBounds;

	public WildcardTypeImpl(Type[] upperBounds, Type[] lowerBounds)
	{
		if (upperBounds.length == 0)
			throw new IllegalArgumentException(
					"There must be at least one upper bound. For an unbound wildcard, the upper bound must be Object");
		this.upperBounds = upperBounds;
		this.lowerBounds = lowerBounds;
	}

	public Type[] getUpperBounds()
	{
		return upperBounds;
	}

	public Type[] getLowerBounds()
	{
		return lowerBounds;
	}

	@Override
	public boolean equals(Object obj)
	{
		if (!(obj instanceof WildcardType))
			return false;
		WildcardType other = (WildcardType) obj;
		return Arrays.equals(lowerBounds, other.getLowerBounds())
				&& Arrays.equals(upperBounds, other.getUpperBounds());
	}

	@Override
	public int hashCode()
	{
		return Arrays.hashCode(lowerBounds) ^ Arrays.hashCode(upperBounds);
	}

	@Override
	public String toString()
	{
		if (lowerBounds.length > 0)
		{
			return "? super " + Generics.getTypeName(lowerBounds[0]);
		}
		else if (upperBounds[0] == Object.class)
		{
			return "?";
		}
		else
		{
			return "? extends " + Generics.getTypeName(upperBounds[0]);
		}
	}
}