问题
I am using spark-sql.2.4.1v , datastax-java-cassandra-connector_2.11-2.4.1.jar and java8.
I have cassandra table like
create company(company_id int PRIMARY_KEY, company_name text);
JavaBean as below
@Table(name = "company")
class CompanyRecord(
@PartitionKey(0)
@Column(name="company_id")
Integer companyId;
@Column(name="company_name")
String companyName;
//getter and setters
//default & parametarized constructors
)
I have spark code below save the data into cassandra table.
Dataset<Row> latestUpdatedDs = joinUpdatedRecordsDs.select("company_id", "company_name"); /// select from other source like xls sheet
Encoder<CompanyRecord> comanyEncoder = Encoders.bean(CompanyRecord.class);
Dataset<CompanyRecord> inputDs = latestUpdatedDs.as(comanyEncoder );
inputDs
.write()
.format("org.apache.spark.sql.cassandra")
.option("table","company")
.option("keyspace", "ks_one")
.mode(SaveMode.Append)
.save();
Giving error like below
ERROR org.apache.spark.sql.catalyst.expressions.codegen.CodeGenerator - failed to compile: org.codehaus.commons.compiler.CompileException: File 'generated.java', Line 176, Column 75: A method named "toString" is not declared in any enclosing class nor any supertype, nor through a static import
org.codehaus.commons.compiler.CompileException: File 'generated.java', Line 176, Column 75: A method named "toString" is not declared in any enclosing class nor any supertype, nor through a static import
at org.codehaus.janino.UnitCompiler.compileError(UnitCompiler.java:12124)
Exception in thread "main" java.util.NoSuchElementException: Columns not found in table ks_one.company:
companyId, companyName
at com.datastax.spark.connector.SomeColumns.selectFrom(ColumnSelector.scala:44)
at com.datastax.spark.connector.writer.TableWriter$.apply(TableWriter.scala:385)
> Question:
Even though I am using annotation for mapping , why I am getting error ? How to fix this without changing the Java Bean field names ( i.e. from companyId to company_id) ?
来源:https://stackoverflow.com/questions/58592097/how-to-map-javabean-columsn-with-casssandra-table-fields