fix bug

hutool-json/src/test/java/cn/hutool/json/IssueI5OMSCTest.java

@@ -0,0 +1,26 @@
+package cn.hutool.json;
+
+import cn.hutool.core.collection.ListUtil;
+import cn.hutool.core.io.resource.ResourceUtil;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Predicate多层过滤
+ */
+public class IssueI5OMSCTest {
+
+	@Test
+	public void filterTest(){
+		final JSONObject json = JSONUtil.parseObj(ResourceUtil.readUtf8Str("issueI5OMSC.json"));
+
+		final String s = json.toJSONString(0, (entry) -> {
+			final Object key = entry.getKey();
+			if(key instanceof String){
+				return ListUtil.of("store", "bicycle", "color", "book", "author").contains(key);
+			}
+			return true;
+		});
+		Assert.assertEquals("{\"store\":{\"bicycle\":{\"color\":\"red\"},\"book\":[{\"author\":\"Evelyn Waugh\"},{\"author\":\"Evelyn Waugh02\"}]}}", s);
+	}
+}

hutool-json/src/test/java/cn/hutool/json/JSONObjectTest.java

@@ -698,7 +698,7 @@ public class JSONObjectTest {
 				.set("d", true);
 
 		final String s = json1.toJSONString(0, (pair) -> {
-			pair.setKey(StrUtil.toUnderlineCase(pair.getKey()));
+			pair.setKey(StrUtil.toUnderlineCase(pair.getKey().toString()));
 			return true;
 		});
 		Assert.assertEquals("{\"a_key\":\"value1\",\"b_job\":\"value2\",\"c_good\":\"value3\",\"d\":true}", s);

hutool-json/src/test/resources/issueI5OMSC.json

@@ -0,0 +1,32 @@
+{
+  "store": {
+    "bicycle": {
+      "color": "red",
+      "price": 19.95
+    },
+    "book": [
+      {
+        "category": "fiction",
+        "author": "Evelyn Waugh",
+        "title": "Sword of Honour",
+        "price": 12.99,
+        "items": [
+          {
+            "name": "wujing001",
+            "age": 18
+          },
+          {
+            "name": "wujing002",
+            "age": 18
+          }
+        ]
+      },
+      {
+        "category": "fiction02",
+        "author": "Evelyn Waugh02",
+        "title": "Sword of Honour02",
+        "price": 12.99
+      }
+    ]
+  }
+}