方块事件侦探

读取现场 · 位置见本节说明

var player = event.getPlayer();
var block = event.getBlock();
Material type = block.getType();
String worldName = block.getWorld().getName();

临时诊断日志 · 位置见本节说明

getLogger().info(player.getName() + " -> " + type
        + " @ " + block.getX() + "," + block.getY() + "," + block.getZ());

只处理练习世界 · 位置见本节说明

if (!event.getBlock().getWorld().getName().equals("world")) return;

执照只检查生存模式 · 位置见本节说明

// 本句放在出生点保护之后
if (event.getPlayer().getGameMode() != GameMode.SURVIVAL) return;

统一判断矿石 · 位置见本节说明

private boolean isDiamond(Material type) {
    return type == Material.DIAMOND_ORE
            || type == Material.DEEPSLATE_DIAMOND_ORE;
}

快速退出无关方块 · 位置见本节说明

if (!isDiamond(event.getBlock().getType())) return;
// 下面只处理两种钻石矿

拒绝无执照开采 · 位置见本节说明

if (!player.hasPermission("blockacademy.mine.diamond")) {
    event.setCancelled(true);
    player.sendMessage(Component.text("钻石矿需要矿工执照"));
    return;
}

本课权限声明 · 位置见本节说明

permissions:
  blockacademy.mine.diamond:
    default: op
  blockacademy.bypass:
    default: op

不用开平方也能比较 · 位置见本节说明

double dx = (double) block.getX() - spawn.getBlockX();
double dz = (double) block.getZ() - spawn.getBlockZ();
boolean protectedArea = dx * dx + dz * dz <= 100.0;

规则方法 · 位置见本节说明

@EventHandler(ignoreCancelled = true)
public void protect(BlockBreakEvent event) {
    // 检查条件，必要时 setCancelled(true)
}

观察方法 · 位置见本节说明

@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
public void observe(BlockBreakEvent event) {
    // 只观察，不取消，不恢复，不修改方块
}

把无关事件尽早放行 · 位置见本节说明

if (!inLessonWorld(event)) return;
if (event.getPlayer().getGameMode() != GameMode.SURVIVAL) return;
if (!isDiamond(event.getBlock().getType())) return;

错误的事件做法 · 故意错误，先预测再修复

// 不要在每一次挖矿事件里调用耗时操作
// 下载网页、扫描整个世界、保存巨大文件

完整 MiningRules 类 · 完整文件

package de.teacherma.lesson33;

public final class MiningRules {
    private MiningRules() { }
    public static boolean isProtected(int x, int z, int sx, int sz) {
        double dx = (double) x - sx;
        double dz = (double) z - sz;
        return dx * dx + dz * dz <= 100.0;
    }
}

在普通 main 中验算 · 位置见本节说明

System.out.println(MiningRules.isProtected(6, 8, 0, 0));
System.out.println(MiningRules.isProtected(10, 1, 0, 0));
System.out.println(MiningRules.isProtected(106, 208, 100, 200));

运行结果

true
false
true

主类第1部分 · 本段1/2，顺序连接

package de.teacherma.lesson33;

import net.kyori.adventure.text.Component;
import org.bukkit.GameMode;
import org.bukkit.Material;
import org.bukkit.event.EventHandler;
import org.bukkit.event.EventPriority;
import org.bukkit.event.Listener;
import org.bukkit.event.block.BlockBreakEvent;
import org.bukkit.plugin.java.JavaPlugin;

public final class MinerLicensePlugin extends JavaPlugin implements Listener {
    @Override
    public void onEnable() {
        getServer().getPluginManager().registerEvents(this, this);
    }
    private boolean inLessonWorld(BlockBreakEvent event) {
        return event.getBlock().getWorld().getName().equals("world");
    }
    private boolean isDiamond(Material type) {
        return type == Material.DIAMOND_ORE
                || type == Material.DEEPSLATE_DIAMOND_ORE;
    }
    @EventHandler(ignoreCancelled = true)
    public void protect(BlockBreakEvent event) {

主类第1部分 · 本段2/2，顺序连接

        if (!inLessonWorld(event)) return;
        var player = event.getPlayer();
        var block = event.getBlock();
        var spawn = block.getWorld().getSpawnLocation();
        boolean nearSpawn = MiningRules.isProtected(block.getX(), block.getZ(),
                spawn.getBlockX(), spawn.getBlockZ());
        if (nearSpawn && !player.hasPermission("blockacademy.bypass")) {

主类第2部分 · 顺序接在同一源文件

            event.setCancelled(true);
            player.sendMessage(Component.text("出生点十格以内请保留原貌"));
            return;
        }
        if (player.getGameMode() != GameMode.SURVIVAL) return;
        if (isDiamond(block.getType())
                && !player.hasPermission("blockacademy.mine.diamond")) {
            event.setCancelled(true);
            player.sendMessage(Component.text("钻石矿需要矿工执照"));
        }
    }

    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
    public void observe(BlockBreakEvent event) {
        if (!inLessonWorld(event)) return;
        if (event.getPlayer().getGameMode() != GameMode.SURVIVAL) return;
        if (!isDiamond(event.getBlock().getType())) return;
        getServer().broadcast(Component.text(
                event.getPlayer().getName() + " 获准开采钻石矿！"));
    }
}

src/main/resources/plugin.yml · 完整文件

name: BlockAcademyL33
version: 1.0.0
main: de.teacherma.lesson33.MinerLicensePlugin
api-version: '1.21.11'
author: TeacherMa
website: https://www.teacher-ma.de
permissions:
  blockacademy.mine.diamond:
    default: op
  blockacademy.bypass:
    default: op

L33RuleCheck.java · 完整文件

import de.teacherma.lesson33.MiningRules;

public class L33RuleCheck {
    public static void main(String[] args) {
        System.out.println(MiningRules.isProtected(0, 0, 0, 0));
        System.out.println(MiningRules.isProtected(6, 8, 0, 0));
        System.out.println(MiningRules.isProtected(10, 1, 0, 0));
        System.out.println(MiningRules.isProtected(106, 108, 100, 100));
    }
}

运行结果

true
true
false
true

checks/sources.txt · 完整内容

src/main/java/de/teacherma/lesson33/MiningRules.java
checks/L33RuleCheck.java

项目根目录终端命令 · 分别执行两行

javac -encoding UTF-8 -d checks/out @checks/sources.txt
java -cp checks/out L33RuleCheck