Hi Polarisary,
The fields of your `UserTableFunction` maybe not serializable like
`Connection` and `PreparedStatement`. So you can make them `transient` and
let them not participate in the serialization.
Hope this helps.
Polarisary <polaris...@gmail.com> 于2019年12月26日周四 下午4:47写道：
> Hi all
> When I use udf, it throws Unable to serialize Exception as follows:
>
> Exception in thread "main" org.apache.flink.table.api.ValidationException:
> Unable to serialize object 'UserTableFunction' of class
> ‘....udtf.UserTableFunction'.
> at
> org.apache.flink.table.utils.EncodingUtils.encodeObjectToString(EncodingUtils.java:72)
> at
> org.apache.flink.table.functions.UserDefinedFunction.functionIdentifier(UserDefinedFunction.java:45)
> at
> org.apache.flink.table.planner.codegen.CodeGenUtils$.udfFieldName(CodeGenUtils.scala:715)
> at
> org.apache.flink.table.planner.codegen.CodeGeneratorContext.addReusableFunction(CodeGeneratorContext.scala:615)
>
>
> My udf as follows.
>
> public class UserTableFunction extends TableFunction<Row> {
> private static final long serialVersionUID = 1L;
> private HikariCPUtils dbUtils = new HikariCPUtils();
> protected Connection connection;
>
>
> protected PreparedStatement preparedStatement = null;
> @Override
> public void open(FunctionContext context) throws Exception {
> connection = dbUtils.getConnection();
> }
>
> @Override
> public void close() throws Exception {
> if (null != connection)
> connection.close();
> if (null != preparedStatement)
> preparedStatement.close();
> }
>
> public void eval(long uid, int countryId) {
> ...
> Row row = new Row(8);
> try {
> *...*
> collect(row);
> } catch (SQLException e) {
> e.printStackTrace();
> }
> }
>
> @Override
> public TypeInformation<Row> getResultType() {
> return Types.ROW(Types.STRING, Types.STRING, Types.STRING,
> Types.STRING, Types.STRING, Types.STRING, Types.STRING, Types.STRING);
> }
> }
>
>
>
> polaris...@gmail.com
>
>
>
>
>
--
Benchao Li
School of Electronics Engineering and Computer Science, Peking University
Tel:+86-15650713730
Email: libenc...@gmail.com; libenc...@pku.edu.cn
