Basic flatland with biomes world generator bukkit/minecraft

package me.jtjj222.BasicTerrain;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import org.bukkit.Material;
import org.bukkit.World;
import org.bukkit.block.Biome;
import org.bukkit.generator.*;

public class BasicChunkGenerator extends ChunkGenerator {

    void setBlock(int x, int y, int z, byte[][] chunk, Material material) {
        try {
            chunk[y >> 4][((y & 0xF) << 8) | (z << 4) | x] = (byte) material
                    .getId();
        } catch (Exception e) {
            // do nothing
        }
    }

    @Override
    public byte[][] generateBlockSections(World world, Random rand, int chunkXlocationInWorld,
            int chunkZLocationInWorld, BiomeGrid biomeGrid) {

        byte[][] chunk = new byte[world.getMaxHeight()/16][16*16*16];

        for (int inChunkX = 0; inChunkX < 16; inChunkX++) {
            for (int inChunkZ = 0; inChunkZ < 16; inChunkZ++) {

                //in-chunk to world co-ordinates; Used for the noise generator
                int worldX = chunkXlocationInWorld * 16 + inChunkX;
                int worldZ = chunkZLocationInWorld * 16 + inChunkZ;

                /*
                 * Get the PROPOSED biome for this location.
                 * If you want to control biome generation, update the biomes here using setBiome(x,z);
                 *
                 * These values will be sent to the client to control weather and whatnot.
                 */
                Biome currentBiome = biomeGrid.getBiome(inChunkX, inChunkZ);

                Material topBlockType = getTopBlockType(currentBiome);

                setBlock(inChunkX, 64, inChunkZ, chunk, topBlockType);
                for (int y = 0; y < 64; y++) setBlock(inChunkX, y, inChunkZ, chunk, Material.STONE);
            }
        }

        return chunk;
    }

    public Material getTopBlockType(Biome b) {
        Material topBlockType;

        switch (b) {
        case BEACH: topBlockType = Material.SAND;
            break;

        case DESERT: topBlockType = Material.SAND;
            break;

        case DESERT_HILLS: topBlockType = Material.SAND;
            break;

        case EXTREME_HILLS: topBlockType = Material.GRAVEL;
            break;

        case FOREST: topBlockType = Material.GRASS;
            break;

        case FOREST_HILLS: topBlockType = Material.GRASS;
            break;

        case FROZEN_OCEAN: topBlockType = Material.ICE;
            break;

        case FROZEN_RIVER: topBlockType = Material.ICE;
            break;

        case HELL: topBlockType = Material.NETHERRACK;
            break;

        case ICE_MOUNTAINS: topBlockType = Material.SNOW_BLOCK;
            break;

        case ICE_PLAINS: topBlockType = Material.SNOW_BLOCK;
            break;

        case JUNGLE: topBlockType = Material.GRASS;
            break;

        case JUNGLE_HILLS: topBlockType = Material.GRASS;
            break;

        case MUSHROOM_ISLAND: topBlockType = Material.MYCEL;
            break;

        case MUSHROOM_SHORE: topBlockType = Material.MYCEL;
            break;

        case OCEAN: topBlockType = Material.WATER;
            break;

        case PLAINS: topBlockType = Material.GRASS;
            break;

        case RIVER: topBlockType = Material.WATER;
            break;

        case SKY: topBlockType = Material.AIR;
            break;

        case SMALL_MOUNTAINS: topBlockType = Material.WATER;
            break;

        case SWAMPLAND: topBlockType = Material.MYCEL;
            break;

        case TAIGA: topBlockType = Material.GRASS;
            break;

        case TAIGA_HILLS: topBlockType = Material.GRASS;
            break;

        default: topBlockType = Material.GRASS;
        }
        return topBlockType;
    }


    @Override
    public List<BlockPopulator> getDefaultPopulators(World world) {
        ArrayList<BlockPopulator> pops = new ArrayList<BlockPopulator>();
        //Add Block populators here
        return pops;
    }
}