All you need to do is implement a method readJson that reads a single
file given its path. Than, you map the values of column file_path to the
respective JSON content as a string. This can be done via an UDF or
simply Dataset.map:
case class RowWithJsonUri(entity_id: String, file_path: String,
other_useful_id: String)
case class RowWithJsonContent(entity_id: String, json_content: String,
other_useful_id: String)
val ds = Seq(
RowWithJsonUri("id-01f7pqqbxddb3b1an6ntyqx6mg",
"gs://bucket1/path/to/id-01g4he5cb4xqn6s1999k6y1vbd/file_result.json",
"id-2-01g4he5cb4xqn6s1999k6y1vbd"),
RowWithJsonUri("id-01f7pqgbwms4ajmdtdedtwa3mf",
"gs://bucket1/path/to/id-01g4he5cbh52che104rwy603sr/file_result.json",
"id-2-01g4he5cbh52che104rwy603sr"),
RowWithJsonUri("id-01f7pqqbxejt3ef4ap9qcs78m5",
"gs://bucket1/path/to/id-01g4he5cbqmdv7dnx46sebs0gt/file_result.json",
"id-2-01g4he5cbqmdv7dnx46sebs0gt"),
RowWithJsonUri("id-01f7pqqbynh895ptpjjfxvk6dc",
"gs://bucket1/path/to/id-01g4he5cbx1kwhgvdme1s560dw/file_result.json",
"id-2-01g4he5cbx1kwhgvdme1s560dw")
).toDS()
ds.show(false)
+-+---+---+
|entity_id |file_path |other_useful_id |
+-+---+---+
|id-01f7pqqbxddb3b1an6ntyqx6mg|gs://bucket1/path/to/id-01g4he5cb4xqn6s1999k6y1vbd/file_result.json|id-2-01g4he5cb4xqn6s1999k6y1vbd|
|id-01f7pqgbwms4ajmdtdedtwa3mf|gs://bucket1/path/to/id-01g4he5cbh52che104rwy603sr/file_result.json|id-2-01g4he5cbh52che104rwy603sr|
|id-01f7pqqbxejt3ef4ap9qcs78m5|gs://bucket1/path/to/id-01g4he5cbqmdv7dnx46sebs0gt/file_result.json|id-2-01g4he5cbqmdv7dnx46sebs0gt|
|id-01f7pqqbynh895ptpjjfxvk6dc|gs://bucket1/path/to/id-01g4he5cbx1kwhgvdme1s560dw/file_result.json|id-2-01g4he5cbx1kwhgvdme1s560dw|
+-+---+---+
def readJson(uri: String): String = { s"content of $uri" }
ds.map { row => RowWithJsonContent(row.entity_id,
readJson(row.file_path), row.other_useful_id) }.show(false)
+-+--+---+
|entity_id |json_content |other_useful_id |
+-+--+---+
|id-01f7pqqbxddb3b1an6ntyqx6mg|content of
gs://bucket1/path/to/id-01g4he5cb4xqn6s1999k6y1vbd/file_result.json|id-2-01g4he5cb4xqn6s1999k6y1vbd|
|id-01f7pqgbwms4ajmdtdedtwa3mf|content of
gs://bucket1/path/to/id-01g4he5cbh52che104rwy603sr/file_result.json|id-2-01g4he5cbh52che104rwy603sr|
|id-01f7pqqbxejt3ef4ap9qcs78m5|content of
gs://bucket1/path/to/id-01g4he5cbqmdv7dnx46sebs0gt/file_result.json|id-2-01g4he5cbqmdv7dnx46sebs0gt|
|id-01f7pqqbynh895ptpjjfxvk6dc|content of
gs://bucket1/path/to/id-01g4he5cbx1kwhgvdme1s560dw/file_result.json|id-2-01g4he5cbx1kwhgvdme1s560dw|
+-+--+---+
Cheers,
Enrico
Am 10.07.22 um 09:11 schrieb Muthu Jayakumar:
Hello there,
I have a dataframe with the following...
+-+---+---+
|entity_id |file_path
|other_useful_id |
+-+---+---+
|id-01f7pqqbxddb3b1an6ntyqx6mg|gs://bucket1/path/to/id-01g4he5cb4xqn6s1999k6y1vbd/file_result.json|id-2-01g4he5cb4xqn6s1999k6y1vbd|
|id-01f7pqgbwms4ajmdtdedtwa3mf|gs://bucket1/path/to/id-01g4he5cbh52che104rwy603sr/file_result.json|id-2-01g4he5cbh52che104rwy603sr|
|id-01f7pqqbxejt3ef4ap9qcs78m5|gs://bucket1/path/to/id-01g4he5cbqmdv7dnx46sebs0gt/file_result.json|id-2-01g4he5cbqmdv7dnx46sebs0gt|
|id-01f7pqqbynh895ptpjjfxvk6dc|gs://bucket1/path/to/id-01g4he5cbx1kwhgvdme1s560dw/file_result.json|id-2-01g4he5cbx1kwhgvdme1s560dw|
+-+---+---+
I would like to read each row from `file_path` and write the result to
another dataframe containing `entity_id`, `other_useful_id`,
`json_content`, `file_path`.
Assume that I already have the required HDFS url libraries in my
classpath.
Please advice,
Muthu
