修复JSON解析栈溢出部分问题

hutool-json/src/test/java/cn/hutool/json/Issue2555Test.java

@@ -1,3 +1,5 @@
+package cn.hutool.json;
+
 import cn.hutool.json.JSON;
 import cn.hutool.json.JSONConfig;
 import cn.hutool.json.JSONObject;

hutool-json/src/test/java/cn/hutool/json/Issue2746Test.java

@@ -0,0 +1,23 @@
+package cn.hutool.json;
+
+import cn.hutool.core.util.StrUtil;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class Issue2746Test {
+	@Test
+	public void parseObjTest() {
+		final String str = StrUtil.repeat("{", 1500) + StrUtil.repeat("}", 1500);
+		try{
+			JSONUtil.parseObj(str);
+		} catch (final JSONException e){
+			Assert.assertTrue(e.getMessage().startsWith("A JSONObject can not directly nest another JSONObject or JSONArray"));
+		}
+	}
+
+	@Test(expected = JSONException.class)
+	public void parseTest() {
+		final String str = StrUtil.repeat("[", 1500) + StrUtil.repeat("]", 1500);
+		JSONUtil.parseArray(str);
+	}
+}

hutool-json/src/test/java/cn/hutool/json/Issue2749Test.java

@@ -0,0 +1,32 @@
+package cn.hutool.json;
+
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class Issue2749Test {
+
+	@Test
+	@Ignore
+	public void jsonObjectTest() {
+		final Map<String, Object> map = new HashMap<>(1, 1f);
+		Map<String, Object> node = map;
+		for (int i = 0; i < 1000; i++) {
+			//noinspection unchecked
+			node = (Map<String, Object>) node.computeIfAbsent("a", k -> new HashMap<String, Object>(1, 1f));
+		}
+		node.put("a", 1);
+		final String jsonStr = JSONUtil.toJsonStr(map);
+
+		@SuppressWarnings("MismatchedQueryAndUpdateOfCollection")
+		final JSONObject jsonObject = new JSONObject(jsonStr);
+		Assert.assertNotNull(jsonObject);
+
+		// 栈溢出
+		//noinspection ResultOfMethodCallIgnored
+		jsonObject.toString();
+	}
+}