feat(core): MapUtils增加深度合并两个map的方法 (#16)

Author: luoqiz

continew-starter-core/src/main/java/top/continew/starter/core/util/MapUtils.java

@@ -16,8 +16,9 @@
 
 package top.continew.starter.core.util;
 
-import java.util.Map;
-import java.util.Properties;
+import cn.hutool.core.map.MapUtil;
+
+import java.util.*;
 
 /**
  * Map 工具类
@@ -41,4 +42,50 @@ public static Properties toProperties(Map<String, String> source) {
         properties.putAll(source);
         return properties;
     }
+
+    /**
+     * 深度合并两个map
+     * 需要用新的map接收
+     *
+     * @param to   需要合并的map
+     * @param from 需要被合并的map
+     * @return Map<String, Object> 必须重新使用的map
+     * @author luoqiz
+     * @since 2.14.0
+     */
+    public static Map<String, Object> mergeMap(Map<String, Object> to, Map<String, Object> from) {
+        if (MapUtil.isEmpty(to)) {
+            return from;
+        }
+        if (MapUtil.isEmpty(from)) {
+            return to;
+        }
+        if (MapUtil.isEmpty(to) && MapUtil.isEmpty(from)) {
+            return new HashMap<>();
+        }
+        Set<Map.Entry<String, Object>> entries = to.entrySet();
+        Iterator<Map.Entry<String, Object>> iterator = entries.iterator();
+        while (iterator.hasNext()) {
+            Map.Entry<String, Object> kv = iterator.next();
+            String toKey = kv.getKey();
+            Object toValue = kv.getValue();
+            Object fromValue = from.get(toKey);
+            if (fromValue != null) {
+                if (toValue instanceof Map) {
+                    Map<String, Object> childTo = (Map<String, Object>)toValue;
+                    mergeMap(childTo, (Map<String, Object>)fromValue);
+                } else {
+                    to.put(toKey, fromValue);
+                }
+            }
+        }
+
+        Set<String> keys = from.keySet();
+        for (String key : keys) {
+            if (!to.containsKey(key)) {
+                to.put(key, from.get(key));
+            }
+        }
+        return to;
+    }
 }