LevelCache

gistfile1.txt

public class ExponentialLevelCache extends LevelCache {

	private final double modifier;

	public ExponentialLevelCache(int maxLevel, int minLevel, double modifier) {
		super(maxLevel, minLevel);
		this.modifier = modifier;
	}


	@Override
	protected float calculateExperience(int level) {
		return (float) (modifier * Math.pow(level, 2));
	}
}

gistfile2.txt

import org.apache.commons.collections.BidiMap;
import org.apache.commons.collections.bidimap.DualHashBidiMap;

import java.util.HashMap;

/**
 * Represents a LevelCache
 */
public abstract class LevelCache {

	private final BidiMap experienceTable;
	private final int minLevel;

	public LevelCache(int maxLevel, int minLevel) {
		this.minLevel = minLevel;
		if (maxLevel <= minLevel) {
			throw new IllegalArgumentException("The maxLevel must be greater than the minlevel!");
		}

		experienceTable = new DualHashBidiMap(new HashMap(maxLevel - minLevel));
	}

	public void initialise() {
		for (int level = minLevel; level < experienceTable.size(); level++) {
			experienceTable.put(level, getExperience(level));
		}
	}

	public float getExperience(int level) {
		return (Float) experienceTable.get(level);
	}

	protected abstract float calculateExperience(int level);

	public int getLevel(int experience) {
		return (Integer) experienceTable.getKey(experience);
	}
}