add 增加 DataPermissionHelper 类 便于操作数据权限变量

ruoyi-common/src/main/java/com/ruoyi/common/helper/DataPermissionHelper.java

@@ -0,0 +1,45 @@
+package com.ruoyi.common.helper;
+
+import cn.hutool.core.util.ObjectUtil;
+import com.ruoyi.common.utils.ServletUtils;
+
+import javax.servlet.http.HttpServletRequest;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * 数据权限助手
+ *
+ * @author Lion Li
+ * @version 3.5.0
+ */
+@SuppressWarnings("unchecked cast")
+public class DataPermissionHelper {
+
+    private static final String DATA_PERMISSION_KEY = "data:permission";
+
+    public static <T> T getVariable(String key) {
+        Map<String, Object> context = getContext();
+        return (T) context.get(key);
+    }
+
+
+
+    public static void setVariable(String key, Object value) {
+        Map<String, Object> context = getContext();
+        context.put(key, value);
+    }
+
+    public static Map<String, Object> getContext() {
+        HttpServletRequest request = ServletUtils.getRequest();
+        Object attribute = request.getAttribute(DATA_PERMISSION_KEY);
+        if (ObjectUtil.isNull(attribute)) {
+            request.setAttribute(DATA_PERMISSION_KEY, new HashMap<>());
+            attribute = request.getAttribute(DATA_PERMISSION_KEY);
+        }
+        if (attribute instanceof Map) {
+            return (Map<String, Object>) attribute;
+        }
+        throw new NullPointerException("data permission context type exception");
+    }
+}