Hey,
I know, that there are things like BlockTypes, but I can’t use it in this case…
Example:
Id: minecraft:stone
variant: granite
So I want to get the BlockState of granite to place a granite block in my map by using
player.getLocation().setBlock(BLOCKSTATE)
Thanks 
BlockState granite = BlockTypes.STONE.getDefaultState().with(Keys.STONE_TYPE, StoneTypes.GRANITE).get();
This wouldn’t work, because I have to use the blocks id & variant
OK so you have a string instead?
If you know it’s stone, then you can get the StoneType
Optional<StoneType> optStoneType = Sponge.getRegistry().getType(StoneType.class, "granite");
if (optStoneType.isPresent()) {
Optional<BlockType> optBlock = Sponge.getRegistry().getType(BlockType.class, "minecraft:stone");
if (optBlock.isPresent()) {
Optional<BlockState> optState = optBlock.get().getDefaultState().with(Keys.STONE_TYPE, optStoneType.get());
if (optState.isPresent()) {
BlockState blockState = optState.get();
}
}
}
I don’t know, that it’s stone, it could be any block…
Is there no other way? 
Right, then you can use block traits.
Block traits allow for simple strings to be given without knowing any prior information
Optional<BlockType> optBlock = Sponge.getRegistry().getType(BlockType.class, "minecraft:stone");
if (optBlock.isPresent()) {
Optional<BlockTrait> optTrait = Sponge.getRegistry().getType(BlockTrait.class, "variant");
if (optTrait.isPresent()) {
Optional<BlockState> optState = optBlock.get().getDefaultState().withTrait(optTrait.get(), "granite");
if (optState.isPresent()) {
BlockState blockState = optState.get();
}
}
}
So I tried It with following code:
Optional<BlockType> optBlock = Sponge.getRegistry().getType(BlockType.class, "minecraft:stone");
if (optBlock.isPresent()) {
Optional<BlockTrait> optTrait = Sponge.getRegistry().getType(BlockTrait.class, "variant");
if (optTrait.isPresent()) {
Optional<BlockState> optState = optBlock.get().getDefaultState().withTrait(optTrait.get(), "granite");
if (optState.isPresent()) {
BlockState blockState = optState.get();
player.getLocation().setBlock(blockState);
}
}
}
And I got following error:
[19:26:05] [Server thread/ERROR] [Sponge]: Error occurred while executing command 'bi' for source EntityPlayerMP['Hitzk0pf'/1116, l='spawn', x=-1678,09, y=47,24, z=107,60]: null java.lang.NullPointerException at java.util.Objects.requireNonNull(Objects.java:203) ~[?:1.8.0_72] at java.util.Optional.<init>(Optional.java:96) ~[?:1.8.0_72] at java.util.Optional.of(Optional.java:108) ~[?:1.8.0_72] at org.spongepowered.common.registry.SpongeGameRegistry.getRegistryModuleFor(SpongeGameRegistry.java:205) ~[SpongeGameRegistry.class:1.8.9-1732-3.1.0-BETA-1139] at org.spongepowered.common.registry.SpongeGameRegistry.getType(SpongeGameRegistry.java:226) ~[SpongeGameRegistry.class:1.8.9-1732-3.1.0-BETA-1139] at me.Hitzk0pf.CaveCore.commands.Cave.BlockInfo.process(BlockInfo.java:81) ~[BlockInfo.class:?] at org.spongepowered.api.command.dispatcher.SimpleDispatcher.process(SimpleDispatcher.java:331) ~[SimpleDispatcher.class:1.8.9-1732-3.1.0-BETA-1139] at org.spongepowered.common.command.SpongeCommandManager.process(SpongeCommandManager.java:252) [SpongeCommandManager.class:1.8.9-1732-3.1.0-BETA-1139] at net.minecraft.command.ServerCommandManager.func_71556_a(SourceFile:83) [bd.class:?] at net.minecraft.network.NetHandlerPlayServer.func_147361_d(NetHandlerPlayServer.java:809) [lm.class:?] at net.minecraft.network.NetHandlerPlayServer.func_147354_a(NetHandlerPlayServer.java:788) [lm.class:?] at net.minecraft.network.play.client.C01PacketChatMessage.func_148833_a(SourceFile:37) [ie.class:?] at net.minecraft.network.play.client.C01PacketChatMessage.func_148833_a(SourceFile:9) [ie.class:?] at org.spongepowered.common.network.PacketUtil.onProcessPacket(PacketUtil.java:106) [PacketUtil.class:1.8.9-1732-3.1.0-BETA-1139] at net.minecraft.network.PacketThreadUtil$1.onProcessPacket(SourceFile:51) [fh$1.class:?] at net.minecraft.network.PacketThreadUtil$1.run(SourceFile:13) [fh$1.class:?] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_72] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_72] at net.minecraft.util.Util.func_181617_a(SourceFile:44) [g.class:?] at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:660) [MinecraftServer.class:?] at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:344) [ko.class:?] at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:605) [MinecraftServer.class:?] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:481) [MinecraftServer.class:?] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]
Line 81:
Optional<BlockTrait> optTrait = Sponge.getRegistry().getType(BlockTrait.class, "variant");
OK try this:
Optional<BlockType> optBlock = Sponge.getRegistry().getType(BlockType.class, "minecraft:stone");
if (optBlock.isPresent()) {
BlockState defaultState = optBlock.get().getDefaultState();
Optional<BlockTrait<?>> optTrait = defaultState.getTrait("variant");
if (optTrait.isPresent()) {
Optional<BlockState> optState = defaultState.withTrait(optTrait.get(), "granite");
if (optState.isPresent()) {
BlockState blockState = optState.get();
}
}
}
I can’t mark it as solution, but now my code works. Thanks! 
In the future, you can post your questions/issues in the Plugin Development category. This will allow you to mark solutions as solved. 