plugins printing lists of key-block applicability

package com.test;

import com.google.inject.Inject;
import org.slf4j.Logger;
import org.spongepowered.api.Game;
import org.spongepowered.api.block.BlockState;
import org.spongepowered.api.block.BlockType;
import org.spongepowered.api.block.BlockTypes;
import org.spongepowered.api.command.CommandException;
import org.spongepowered.api.command.CommandResult;
import org.spongepowered.api.command.CommandSource;
import org.spongepowered.api.command.args.CommandContext;
import org.spongepowered.api.command.spec.CommandSpec;
import org.spongepowered.api.data.key.Key;
import org.spongepowered.api.data.key.Keys;
import org.spongepowered.api.event.Listener;
import org.spongepowered.api.event.block.InteractBlockEvent;
import org.spongepowered.api.event.game.state.GameInitializationEvent;
import org.spongepowered.api.plugin.Plugin;
import org.spongepowered.api.text.Text;

import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

@Plugin(id = "mytestplugin42", name = "My Test plugin 42", version = "1.0")
public class MyTestPlugin42
{
    @Inject
    private Logger logger;

    @Inject
    private Game game;

    private CommandResult cmdOnPrintBlockData(CommandSource src, CommandContext args) throws CommandException
    {
        StringBuilder sb = new StringBuilder();

        sb.append("\r\n");

        Class<BlockTypes> c = BlockTypes.class;

        try {
            Field[] fields = c.getDeclaredFields();
            for(Field f : fields){
                String blockName = f.getName();
                BlockType blockType = null;
                blockType = (BlockType)f.get(c);
                sb.append(blockName);
                sb.append("\r\n");

                BlockState blockState = blockType.getDefaultState();

                Class<Keys> kc = Keys.class;
                Field[] keyFields = kc.getDeclaredFields();
                for (Field kf : keyFields){
                    String keyName = kf.getName();
                    Key key = null;
                    key = (Key)kf.get(kc);

                    if (key == null) continue;



                    if (blockState.supports(key)) {
                        sb.append("    ");
                        sb.append(keyName);
                        sb.append("\r\n");
                    }
                }
                sb.append("\r\n");
            }
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

        String s = sb.toString();

        try {
            PrintWriter out = new PrintWriter("!KeysForBlocks.txt");
            out.println(s);
            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        return CommandResult.success();
    }

    private CommandResult cmdOnPrintDataOfBlock(CommandSource src, CommandContext args) throws CommandException
    {
        StringBuilder sb = new StringBuilder();

        sb.append("\r\n");

        try {
            Class<Keys> kc = Keys.class;
            Field[] keyFields = kc.getDeclaredFields();
            for (Field kf : keyFields){
                String keyName = kf.getName();
                Key key = null;
                key = (Key)kf.get(kc);

                if (key == null) continue;

                Class<BlockTypes> c = BlockTypes.class;

                List<String> supportedBlocks = new ArrayList<>();

                Field[] fields = c.getDeclaredFields();
                for(Field f : fields){
                    String blockName = f.getName();
                    BlockType blockType = null;
                    blockType = (BlockType)f.get(c);

                    BlockState blockState = blockType.getDefaultState();

                    if (blockState.supports(key)) {
                        supportedBlocks.add(blockName);
                    }
                }

                if (supportedBlocks.size()>0) {
                    sb.append(keyName);
                    sb.append("\r\n");

                    for (String supportedBlock : supportedBlocks) {
                        sb.append("    ");
                        sb.append(supportedBlock);
                        sb.append("\r\n");
                    }
                    sb.append("\r\n");
                }
            }
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

        String s = sb.toString();

        try {
            PrintWriter out = new PrintWriter("!BlocksForKeys.txt");
            out.println(s);
            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        return CommandResult.success();
    }

    @Listener
    public void onGameInitialization(GameInitializationEvent event)
    {
        CommandSpec myCommandSpec = CommandSpec.builder()
                .executor(this::cmdOnPrintBlockData)
                .build();

        CommandSpec myDataSpec = CommandSpec.builder()
                .executor(this::cmdOnPrintDataOfBlock)
                .build();

        game.getCommandManager().register(this, myCommandSpec, "printblockdata", "printbd");
        game.getCommandManager().register(this, myDataSpec, "printdatablock", "printdb");

        logger.info("PEW!");
    }

}