From 29fc167548718c96d59e0a67ec06d32db763bad2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wilson-=CE=B2?=
 <40427110+Wilson-BT@users.noreply.github.com>
Date: Thu, 29 Sep 2022 11:37:10 +0800
Subject: [PATCH] [Bug](Datax)Fix bug that the dataxwriter will drop column
 when convert map to json (#13042)
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Content-Type: text/plain; charset=UTF-8
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* fix bug that when value is null，toJSONString will drop this key value.
---
 docs/zh-CN/docs/ecosystem/datax.md                             | 2 ++
 .../datax/plugin/writer/doriswriter/DorisJsonCodec.java        | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/docs/zh-CN/docs/ecosystem/datax.md b/docs/zh-CN/docs/ecosystem/datax.md
index feb8429d3f..46006122b8 100644
--- a/docs/zh-CN/docs/ecosystem/datax.md
+++ b/docs/zh-CN/docs/ecosystem/datax.md
@@ -180,6 +180,7 @@ PROPERTIES (
                         "password": "xxx",
                         "postSql": [],
                         "preSql": [],
+                        "format":"csv|json",
                         "loadProps": {
                         },
                         "maxBatchRows" : 300000,
@@ -191,5 +192,6 @@ PROPERTIES (
     }
 }
 ```
+> 注意：```format``` 参数默认值：```csv```，如果想要使用```json```格式，需要在配置中指定```format``` 为```json```.
 
 4.执行datax任务，具体参考 [datax官网](https://github.com/alibaba/DataX/blob/master/userGuid.md)
diff --git a/extension/DataX/doriswriter/src/main/java/com/alibaba/datax/plugin/writer/doriswriter/DorisJsonCodec.java b/extension/DataX/doriswriter/src/main/java/com/alibaba/datax/plugin/writer/doriswriter/DorisJsonCodec.java
index 664b9d3629..063503bbb3 100644
--- a/extension/DataX/doriswriter/src/main/java/com/alibaba/datax/plugin/writer/doriswriter/DorisJsonCodec.java
+++ b/extension/DataX/doriswriter/src/main/java/com/alibaba/datax/plugin/writer/doriswriter/DorisJsonCodec.java
@@ -19,6 +19,7 @@ package com.alibaba.datax.plugin.writer.doriswriter;
 
 import com.alibaba.datax.common.element.Record;
 import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.serializer.SerializerFeature;
 
 import java.util.HashMap;
 import java.util.List;
@@ -45,6 +46,6 @@ public class DorisJsonCodec extends DorisCodec {
             rowMap.put(fieldName, this.convertColumn(row.getColumn(idx)));
             ++idx;
         }
-        return JSON.toJSONString(rowMap);
+        return JSON.toJSONString(rowMap, SerializerFeature.WriteMapNullValue);
     }
 }