From 745826012a97e2c2965d53fcc80dcd0b1976f0cb Mon Sep 17 00:00:00 2001
From: misakacoder <210086826@qq.com>
Date: Tue, 5 Mar 2024 13:35:10 +0800
Subject: [PATCH] fix 3504

---
 .../core/convert/ConverterRegistry.java       |  3 ++-
 .../java/cn/hutool/json/Issue3504Test.java    | 26 +++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 hutool-json/src/test/java/cn/hutool/json/Issue3504Test.java

diff --git a/hutool-core/src/main/java/cn/hutool/core/convert/ConverterRegistry.java b/hutool-core/src/main/java/cn/hutool/core/convert/ConverterRegistry.java
index d9cda806f..8f3ebb68c 100755
--- a/hutool-core/src/main/java/cn/hutool/core/convert/ConverterRegistry.java
+++ b/hutool-core/src/main/java/cn/hutool/core/convert/ConverterRegistry.java
@@ -153,7 +153,8 @@ public class ConverterRegistry implements Serializable {
 	 */
 	@SuppressWarnings("unchecked")
 	public <T> Converter<T> getDefaultConverter(Type type) {
-		return (null == defaultConverterMap) ? null : (Converter<T>) defaultConverterMap.get(TypeUtil.getClass(type));
+		Class<?> key = TypeUtil.getClass(type);
+		return (null == defaultConverterMap || null == key) ? null : (Converter<T>) defaultConverterMap.get(key);
 	}
 
 	/**
diff --git a/hutool-json/src/test/java/cn/hutool/json/Issue3504Test.java b/hutool-json/src/test/java/cn/hutool/json/Issue3504Test.java
new file mode 100644
index 000000000..577dbe6da
--- /dev/null
+++ b/hutool-json/src/test/java/cn/hutool/json/Issue3504Test.java
@@ -0,0 +1,26 @@
+package cn.hutool.json;
+
+import lombok.Data;
+import org.junit.Test;
+
+/**
+ * https://github.com/dromara/hutool/issues/3504
+ */
+public class Issue3504Test {
+
+	@Test
+	public void test3504() {
+		JsonBean jsonBean = new JsonBean();
+		jsonBean.setName("test");
+		jsonBean.setClasses(new Class[]{String.class});
+		String huToolJsonStr = JSONUtil.toJsonStr(jsonBean);
+		System.out.println("hutool json str-------" + huToolJsonStr);
+		System.out.println(JSONUtil.toBean(huToolJsonStr, JsonBean.class));
+	}
+
+	@Data
+	public static class JsonBean {
+		private String name;
+		private Class<?>[] classes;
+	}
+}