给mention bot一个获取玩家列表的http接口

src/main/java/de/strifel/VTools/OnlinePlayerQueryService.java

@@ -0,0 +1,56 @@
+package de.strifel.VTools;
+
+import com.google.gson.Gson;
+import com.sun.net.httpserver.HttpServer;
+import com.velocitypowered.api.proxy.Player;
+import org.jetbrains.annotations.TestOnly;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.InetSocketAddress;
+import java.util.ArrayList;
+import java.util.Collection;
+
+public class OnlinePlayerQueryService {
+
+
+    private final VTools plugin;
+
+    public OnlinePlayerQueryService(VTools plugin) {
+        this.plugin = plugin;
+    }
+
+    private static final Gson gson = new Gson();
+
+    public void register() {
+        try {
+            HttpServer server = HttpServer.create(new InetSocketAddress(17611), 0);
+
+            server.createContext("/api/getOnlinePlayers", exchange -> {
+                Collection<Player> players = plugin.getServer().getAllPlayers();
+                ArrayList<String> playerNames = new ArrayList<>(players.size());
+                for (Player player : players) {
+                    playerNames.add(player.getUsername());
+                }
+                exchange.getResponseHeaders().set("Content-Type", "application/json");
+                exchange.sendResponseHeaders(200, 0);
+
+                try (OutputStream os = exchange.getResponseBody()) {
+                    String response = gson.toJson(playerNames);
+                    os.write(response.getBytes());
+                }
+            });
+
+            server.start();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @TestOnly
+    public static void main(String[] args) {
+        ArrayList<String> arrayList = new ArrayList<>();
+        arrayList.add("jerry");
+        System.out.println(gson.toJson(arrayList));
+    }
+}

src/main/java/de/strifel/VTools/VTools.java

@@ -46,6 +46,7 @@ public class VTools {
         new PlayerStatus(this).register();
         new GlobalChat(this).register();
         new ServerCloser(this).register();
+        new OnlinePlayerQueryService(this).register();
     }
 
     public ProxyServer getServer() {