add test

hutool-json/src/test/java/cn/hutool/json/Issue2997Test.java

@@ -0,0 +1,13 @@
+package cn.hutool.json;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class Issue2997Test {
+	@Test
+	public void toBeanTest() {
+		// https://github.com/dromara/hutool/issues/2997
+		final Object o = JSONUtil.toBean("{}", Object.class);
+		Assert.assertEquals(JSONObject.class, o.getClass());
+	}
+}