Major Description
1.First, I have an object RawLogPlayload which has an field: long timestamp
2.Then I try to join two Dataset<RawLogPlayload> and select some of the columns
Following is the code Snippet
extractedRawTc.printSchema(); // output1
Dataset<RawLogPayload> extractedRawW3cFilled = extractedRawW3c.alias("extractedRawW3c")
.join(extractedRawTc.alias("extractedRawTc"), functions.col("extractedRawW3c.rawsessionid").equalTo(functions.col("extractedRawTc.rawsessionid")), "inner")
.select(functions.col("extractedRawW3c.df_logdatetime"), functions.col("extractedRawW3c.rawsessionid"), functions.col("extractedRawTc.uid"),
functions.col("extractedRawW3c.time"),functions.col("extractedRawW3c.T"),functions.col("extractedRawW3c.url"),functions.col("extractedRawW3c.wid"),
functions.col("extractedRawW3c.tid"), functions.col("extractedRawW3c.fid"),functions.col("extractedRawW3c.string1"),
functions.col("extractedRawW3c.curWindow"), functions.col("extractedRawW3c.timestamp"))
.as(Encoders.bean(RawLogPayload.class));
extractedRawW3cFilled.printSchema(); // output2
3. After run this, it will cast following exception
2019-03-20 15:28:31 ERROR CodeGenerator:91 ## failed to compile: org.codehaus.commons.compiler.CompileException: File 'generated.java', Line 103, Column 32: No applicable constructor/method found for actual parameters "org.apache.spark.unsafe.types.UTF8String"; candidates are: "public void com.microsoft.datamining.spartan.api.core.RawLogPayload.setTimestamp(long)"
org.codehaus.commons.compiler.CompileException: File 'generated.java', Line 103, Column 32: No applicable constructor/method found for actual parameters "org.apache.spark.unsafe.types.UTF8String"; candidates are: "public void com.xxxx.xxxx.spartan.api.core.RawLogPayload.setTimestamp(long)"
at org.codehaus.janino.UnitCompiler.compileError(UnitCompiler.java:11821)
at org.codehaus.janino.UnitCompiler.findMostSpecificIInvocable(UnitCompiler.java:8910)
Output1 extractedRawTc schema
root
|-- curWindow: string (nullable = true)
|-- df_logdatetime: string (nullable = true)
|-- fid: string (nullable = true)
|-- rawsessionid: string (nullable = true)
|-- string1: string (nullable = true)
|-- t: string (nullable = true)
|-- tid: string (nullable = true)
|-- time: string (nullable = true)
|-- timestamp: long (nullable = true)
|-- uid: string (nullable = true)
|-- url: string (nullable = true)
|-- wid: string (nullable = true)
Output2 extractedRawW3cFilled schema
root
|-- df_logdatetime: string (nullable = true)
|-- rawsessionid: string (nullable = true)
|-- uid: string (nullable = true)
|-- time: string (nullable = true)
|-- T: string (nullable = true)
|-- url: string (nullable = true)
|-- wid: string (nullable = true)
|-- tid: string (nullable = true)
|-- fid: string (nullable = true)
|-- string1: string (nullable = true)
|-- curWindow: string (nullable = true)
|-- timestamp: long (nullable = true)
My question: the schema of column timestamp is long, but from the exception log, it seems after selecting the datatype of timestamp becomes UTF8String, Why would this happen? Is it a bug? If not could you point how to use it correctly?
Thanks