使用Datax进行数据迁移行报错，经DataX智能分析,该任务最可能的错误原因是:

com.alibaba.datax.common.exception.DataXException: Code:[Framework-02], Description:[DataX引擎运行过程出错，具体原因请参看DataX运行结束时的错误诊断信息 .]. - java.lang.ClassCastException: com.alibaba.fastjson.JSONObject cannot be cast to java.lang.String

请问是什么原因

我的mysql.json 配置如下

{

"job": {

"content": [

{

"reader": {

"name": "mysqlreader",

"parameter": {

"sliceRecordCount": 10,

"column": [

"*"

],

"connection": [

{

"jdbcUrl": [

"jdbc:mysql://10.xxx.xx.xxx:3306/xxxxx"

],

"table": [

"auth_user_user_permissions"

]

}

],

"password": "xxxxx",

"username": "xxxx"

}

},

"writer": {

"name": "mysqlwriter",

"parameter": {

"encoding": "UTF-8",

"column": [

{

"name": "id",

"type": "INT"

},

{

"name": "user_id",

"type": "INT"

},

{

"name": "permission_id",

"type": "INT"

}

],

"connection": [

{

"jdbcUrl": "jdbc:mysql://10.xxx.xx.xxxx:3306/xxxx",

"table": [

"test"

]

}

],

"password": "xxxxx",

"username": "xxxx"

}

}

}

],

"setting": {

"speed": {

"channel": 5

}

}

}

}