[Add] Exec 添加一个预期(?)的启动模块;

[Add] ApplicationMain 程序主入口, 负责初始化项目运行环境和启动项目;
[Add] log4j2.xml 使用上一版日志配置, 后续会有调整;
[Add] cgj_setting.json 初始配置文件, 需等 Core 模块完成后才会具体编写;

ContentGrabbingJi-exec/src/main/java/net/lamgc/cgj/ApplicationMain.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2020  LamGC
+ *
+ * ContentGrabbingJi is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * ContentGrabbingJi is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.lamgc.cgj;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * ContentGrabbingJi 启动主类.
+ *
+ * 请不要在该类，甚至是该模块（指 exec 模块）开发任何与启动项目无关的功能！
+ * @author LamGC
+ */
+public class ApplicationMain {
+
+    private final static Logger log = LoggerFactory.getLogger(ApplicationMain.class);
+
+    public static void main(String[] args) {
+        log.info("ContentGrabbingJi 正在启动中...");
+        beforeRun();
+        log.info("初始化完成, 正在启动Core...");
+        run();
+        log.info("正在清理运行时内容...");
+        afterRun();
+        log.info("ContentGrabbingJi 退出.");
+    }
+
+    private static void beforeRun() {}
+
+    private static void run() {}
+
+    private static void afterRun() {}
+
+}