From 3ddd11f9c934b1784525a66d2933f373b460c4c5 Mon Sep 17 00:00:00 2001
From: yexuejc007 <ZAQ!2wsx>
Date: Mon, 29 May 2023 17:30:07 +0800
Subject: [PATCH] =?UTF-8?q?[update]=20JsonUtil=20=E5=8D=87=E7=BA=A7?=
 =?UTF-8?q?=E4=BC=98=E5=8C=96=EF=BC=8C=E5=A2=9E=E5=8A=A0=E7=89=B9=E6=AE=8A?=
 =?UTF-8?q?=E9=9C=80=E6=B1=82String=E7=9A=84=E5=8F=8D=E5=BA=8F=E5=88=97?=
 =?UTF-8?q?=E5=8C=96?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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---
 .../base/converter/StringDeserializer.java    | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 src/main/java/com/yexuejc/base/converter/StringDeserializer.java

diff --git a/src/main/java/com/yexuejc/base/converter/StringDeserializer.java b/src/main/java/com/yexuejc/base/converter/StringDeserializer.java
new file mode 100644
index 0000000..d5b2e75
--- /dev/null
+++ b/src/main/java/com/yexuejc/base/converter/StringDeserializer.java
@@ -0,0 +1,38 @@
+package com.yexuejc.base.converter;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+
+import java.io.IOException;
+
+/**
+ * <pre>
+ * json中的“”转String对象时值为null
+ * 例子：{str:""} ->
+ * JsonBean{
+ *  public String str;
+ * }
+ * str的值为null [不使用{@link StringDeserializer},str的值为“”]
+ * </pre>
+ *
+ * <pre>
+ *     使用方式：
+ *     jsonMapper.registerModule(new SimpleModule().addDeserializer(String.class, new StringDeserializer()));
+ * </pre>
+ *
+ * @author yexuejc
+ * @date 2022/10/08
+ */
+public class StringDeserializer extends JsonDeserializer<String> {
+
+    @Override
+    public String deserialize(JsonParser jsonParser, DeserializationContext deserializationContext)
+            throws IOException {
+        String timeString = jsonParser.getValueAsString();
+        if ("".equals(timeString)) {
+            return null;
+        }
+        return timeString;
+    }
+}
\ No newline at end of file