Hi Zerah,
You could try to replace
```
value_schema = avro.schema.parse(<reader schema goes here>)
```
with the following code:
```
JSchemaParser = get_gateway().jvm.org.apache.avro.Schema.Parser
value_schema = JSchemaParser().parse(value_schema_str)
```
The reason is that ```value_schema = avro.schema.parse(<reader schema goes
here>) ``` will create a Python object instead of Java object.
Regards,
Dian
> 2021年5月19日 下午5:23，Zerah J <connectze...@gmail.com> 写道：
>
> Hi Dian,
>
> Type of value_schema is <class 'avro.schema.RecordSchema'>
>
> I have only a Json schema string and schema registry url. Please find below
> snippet :
>
> import avro.schema
>
> value_schema_str = """
> {
> "namespace": "com.nextgen.customer",
> "type": "record",
> "name": "employee",
> "doc": "Customer Details Value Schema.",
> "fields": [
> {
> "doc": "String Value",
> "name": "emp_name",
> "type": "string"
> },
> {
> "doc": "String Value",
> "name": "emp_id",
> "type": "string"
> }
> ]
> }
> value_schema = avro.schema.parse(value_schema_str)
> schema_url = "http://host:port";
>
>
> How can I create Java Schema object from this schema string and pass it from
> python method ?
>
>
> Regards,
> Zerah
>
>
> On Wed, May 19, 2021 at 1:57 PM Dian Fu <dian0511...@gmail.com
> <mailto:dian0511...@gmail.com>> wrote:
> Hi Zerah,
>
> What’s the type of value_schema? It should be a Java object of type Schema.
> From the exception, it seems that it’s a class instead of object. Is this
> true?
>
> Regards,
> Dian
>
>> 2021年5月19日 下午3:41，Zerah J <connectze...@gmail.com
>> <mailto:connectze...@gmail.com>> 写道：
>>
>> Hi Dian,
>>
>> Thanks for your suggestion.
>>
>> I tried to invoke ConfluentRegistryAvroDeserializationSchema.forGeneric
>> method from Python. But it's not working. Kindly check the code snippet
>> below :
>>
>> class MyAvroRowDeserializationSchema(DeserializationSchema):
>>
>> def __init__(self, record_class: str = None, avro_schema_string: schema
>> = None, url: str = None):
>> JConfluentAvroRowDeserializationSchema = get_gateway().jvm \
>>
>> .org.apache.flink.formats.avro.registry.confluent.ConfluentRegistryAvroDeserializationSchema
>> j_deserialization_schema =
>> JConfluentAvroRowDeserializationSchema.forGeneric(avro_schema_string, url)
>>
>> super(MyAvroRowDeserializationSchema,
>> self).__init__(j_deserialization_schema)
>>
>>
>> FlinkKafkaConsumer is now invoked as below using
>> MyAvroRowDeserializationSchema :
>>
>> value_schema = avro.schema.parse(<reader schema goes here>)
>> schema_url = "http://host:port <http://host:port>"
>> deserialization_schema =
>> MyAvroRowDeserializationSchema(avro_schema_string=value_schema,url=schema_url)
>> kafka_source = FlinkKafkaConsumer(
>> topics='my_topic',
>> deserialization_schema=deserialization_schema,
>> properties={'bootstrap.servers': 'host:port', 'group.id
>> <http://group.id/>': 'test_group'})
>>
>> I'm getting the below error :
>>
>> Traceback (most recent call last):
>> File "flinkKafkaAvro.py", line 70, in datastream_api_demo
>> deserialization_schema =
>> MyAvroRowDeserializationSchema(avro_schema_string=value_schema,url=schema_url)
>> File "test_env/tests/SerializeAvroSchema.py", line 52, in __init__
>> j_deserialization_schema =
>> JConfluentAvroRowDeserializationSchema.forGeneric(avro_schema_string, url)
>> File "test_env/venv/lib64/python3.7/site-packages/py4j/java_gateway.py",
>> line 1277, in __call__
>> args_command, temp_args = self._build_args(*args)
>> File "test_env/venv/lib64/python3.7/site-packages/py4j/java_gateway.py",
>> line 1247, in _build_args
>> [get_command_part(arg, self.pool) for arg in new_args])
>> File "test_env/venv/lib64/python3.7/site-packages/py4j/java_gateway.py",
>> line 1247, in <listcomp>
>> [get_command_part(arg, self.pool) for arg in new_args])
>> File "test_env/venv/lib64/python3.7/site-packages/py4j/protocol.py", line
>> 298, in get_command_part
>> command_part = REFERENCE_TYPE + parameter._get_object_id()
>> AttributeError: 'RecordSchema' object has no attribute '_get_object_id'
>>
>>
>>
>> Please suggest how this method should be called. Here the schema used is
>> avro schema.
>>
>> Regards,
>> Zerah
>>
>> On Mon, May 17, 2021 at 3:17 PM Dian Fu <dian0511...@gmail.com
>> <mailto:dian0511...@gmail.com>> wrote:
>> Hi Zerah,
>>
>> I guess you could provide a Python implementation for
>> ConfluentRegistryAvroDeserializationSchema if needed. It’s just a wrapper
>> for the Java implementation and so it’s will be very easy to implement. You
>> could take a look at AvroRowDeserializationSchema [1] as an example.
>>
>> Regards,
>> Dian
>>
>> [1]
>> https://github.com/apache/flink/blob/release-1.13/flink-python/pyflink/common/serialization.py#L303
>>
>> <https://github.com/apache/flink/blob/release-1.13/flink-python/pyflink/common/serialization.py#L303>
>>
>> > 2021年5月17日 下午5:35，Zerah J <connectze...@gmail.com
>> > <mailto:connectze...@gmail.com>> 写道：
>> >
>> > Hi,
>> >
>> > I have below use case
>> >
>> > 1. Read streaming data from Kafka topic using Flink Python API
>> > 2. Apply transformations on the data stream
>> > 3. Write back to different kafka topics based on the incoming data
>> >
>> > Input data is coming from Confluent Avro Producer. By using the existing
>> > pyflink.common.serialization.AvroRowDeserializationSchema, I'm unable to
>> > deserialize the data.
>> >
>> > Please help to process the data as
>> > ConfluentRegistryAvroDeserializationSchema is not available in the Python
>> > API.
>> >
>> > Regards,
>> > Zerah
>>
>
