use paste for messages longer than 512 and fix message sniping

src/main/java/cc/fascinated/bat/common/PasteUtils.java

@@ -0,0 +1,39 @@
+package cc.fascinated.bat.common;
+
+import cc.fascinated.bat.BatApplication;
+import cc.fascinated.bat.model.token.paste.PasteUploadToken;
+import lombok.SneakyThrows;
+import lombok.extern.log4j.Log4j2;
+
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+
+/**
+ * @author Fascinated (fascinated7)
+ */
+@Log4j2
+public class PasteUtils {
+    private static final String PASTE_URL = "https://paste.fascinated.cc/";
+    private static final String PASTE_UPLOAD_URL = PASTE_URL + "api/upload";
+    private static final HttpClient httpClient = HttpClient.newHttpClient();
+
+    /**
+     * Uploads a paste to the paste server
+     *
+     * @param content the content of the paste
+     * @return the paste upload token
+     */
+    @SneakyThrows
+    public static PasteUploadToken uploadPaste(String content) {
+        HttpResponse<String> response = httpClient.send(HttpRequest.newBuilder()
+                        .uri(URI.create(PASTE_UPLOAD_URL))
+                        .POST(HttpRequest.BodyPublishers.ofString(content))
+                        .build(), HttpResponse.BodyHandlers.ofString());
+        PasteUploadToken paste = BatApplication.GSON.fromJson(response.body(), PasteUploadToken.class);
+        paste.setUrl(PASTE_URL + paste.getKey());
+        log.info("Created paste with key \"{}\" ({})", paste.getKey(), paste.getUrl());
+        return paste;
+    }
+}