JsonPath

JSONPath 转换插件

描述

支持使用 JSONPath 选择数据

属性

名称	类型	是否必须	默认值
columns	Array	Yes
row_error_handle_way	Enum	No	FAIL

common options [string]

转换插件的常见参数, 请参考 Transform Plugin 了解详情

row_error_handle_way [Enum]

该选项用于指定当该行发生错误时的处理方式，默认值为 FAIL。

• FAIL：选择FAIL时，数据格式错误会阻塞并抛出异常。
• SKIP：选择SKIP时，数据格式错误会跳过该行数据。

columns[array]

属性

名称	类型	是否必须	默认值
src_field	String	Yes
dest_field	String	Yes
path	String	Yes
dest_type	String	No	String
column_error_handle_way	Enum	No

src_field

要解析的 JSON 源字段

支持的Seatunnel数据类型

• STRING
• BYTES
• ARRAY
• MAP
• ROW

dest_field

使用 JSONPath 后的输出字段

dest_type

目标字段的类型

path

Jsonpath

column_error_handle_way [Enum]

该选项用于指定当列发生错误时的处理方式。

• FAIL：选择FAIL时，数据格式错误会阻塞并抛出异常。
• SKIP：选择SKIP时，数据格式错误会跳过此列数据。
• SKIP_ROW：选择SKIP_ROW时，数据格式错误会跳过此行数据。

读取 JSON 示例

从源读取的数据是像这样的 JSON

{
  "data": {
    "c_string": "this is a string",
    "c_boolean": true,
    "c_integer": 42,
    "c_float": 3.14,
    "c_double": 3.14,
    "c_decimal": 10.55,
    "c_date": "2023-10-29",
    "c_datetime": "16:12:43.459",
    "c_array":["item1", "item2", "item3"]
  }
}

假设我们想要使用 JsonPath 提取属性。

transform {
  JsonPath {
    source_table_name = "fake"
    result_table_name = "fake1"
    columns = [
     {
        "src_field" = "data"
        "path" = "$.data.c_string"
        "dest_field" = "c1_string"
     },
     {
        "src_field" = "data"
        "path" = "$.data.c_boolean"
        "dest_field" = "c1_boolean"
        "dest_type" = "boolean"
     },
     {
        "src_field" = "data"
        "path" = "$.data.c_integer"
        "dest_field" = "c1_integer"
        "dest_type" = "int"
     },
     {
        "src_field" = "data"
        "path" = "$.data.c_float"
        "dest_field" = "c1_float"
        "dest_type" = "float"
     },
     {
        "src_field" = "data"
        "path" = "$.data.c_double"
        "dest_field" = "c1_double"
        "dest_type" = "double"
     },
      {
         "src_field" = "data"
         "path" = "$.data.c_decimal"
         "dest_field" = "c1_decimal"
         "dest_type" = "decimal(4,2)"
      },
      {
         "src_field" = "data"
         "path" = "$.data.c_date"
         "dest_field" = "c1_date"
         "dest_type" = "date"
      },
      {
         "src_field" = "data"
         "path" = "$.data.c_datetime"
         "dest_field" = "c1_datetime"
         "dest_type" = "time"
      },
            {
         "src_field" = "data"
         "path" = "$.data.c_array"
         "dest_field" = "c1_array"
         "dest_type" = "array<string>"        
      }
    ]
  }
}

那么数据结果表 fake1 将会像这样

data	c1_string	c1_boolean	c1_integer	c1_float	c1_double	c1_decimal	c1_date	c1_datetime	c1_array
too much content not to show	this is a string	true	42	3.14	3.14	10.55	2023-10-29	16:12:43.459	["item1", "item2", "item3"]

读取 SeatunnelRow 示例

假设数据行中的一列的类型是 SeatunnelRow，列的名称为 col

SeatunnelRow(col)		other
name	age	....
a	18	....

JsonPath 转换将 seatunnel 的值转换为一个数组。

transform {
  JsonPath {
    source_table_name = "fake"
    result_table_name = "fake1"

    row_error_handle_way = FAIL
    columns = [
     {
        "src_field" = "col"
        "path" = "$[0]"
        "dest_field" = "name"
        "dest_type" = "string"
     },
     {
        "src_field" = "col"
        "path" = "$[1]"
        "dest_field" = "age"
        "dest_type" = "int"
     }
    ]
  }
}

那么数据结果表 fake1 将会像这样:

name	age	col	other
a	18	["a",18]	...

配置异常数据处理策略

您可以配置 row_error_handle_way 与 column_error_handle_way 来处理异常数据，两者都是非必填项。

row_error_handle_way 配置对行数据内所有数据异常进行处理，column_error_handle_way 配置对某列数据异常进行处理，优先级高于 row_error_handle_way。

跳过异常数据行

配置跳过任意列有异常的整行数据

transform {
  JsonPath {

    row_error_handle_way = SKIP
    
    columns = [
     {
        "src_field" = "json_data"
        "path" = "$.f1"
        "dest_field" = "json_data_f1"
     },
     {
        "src_field" = "json_data"
        "path" = "$.f2"
        "dest_field" = "json_data_f2"
     }
    ]
  }
}

跳过部分异常数据列

配置仅对 json_data_f1 列数据异常跳过，填充空值，其他列数据异常继续抛出异常中断处理程序

transform {
  JsonPath {

    row_error_handle_way = FAIL
    
    columns = [
     {
        "src_field" = "json_data"
        "path" = "$.f1"
        "dest_field" = "json_data_f1"
        
        "column_error_handle_way" = "SKIP"
     },
     {
        "src_field" = "json_data"
        "path" = "$.f2"
        "dest_field" = "json_data_f2"
     }
    ]
  }
}

部分列异常跳过整行

配置仅对 json_data_f1 列数据异常跳过整行数据，其他列数据异常继续抛出异常中断处理程序

transform {
  JsonPath {

    row_error_handle_way = FAIL
    
    columns = [
     {
        "src_field" = "json_data"
        "path" = "$.f1"
        "dest_field" = "json_data_f1"
        
        "column_error_handle_way" = "SKIP_ROW"
     },
     {
        "src_field" = "json_data"
        "path" = "$.f2"
        "dest_field" = "json_data_f2"
     }
    ]
  }
}

更新日志

• 添加 JsonPath 转换