Thank you very much. Yes, this works good. And then I took it one step further
to try and get the schema put in the file and also to apply encoding.
FOO fooObj = ....
BAR barObj = ....
BAR barObj2 = ....
ByteArrayOutputStream out = new ByteArrayOutputStream();
DatumWriter<SpecificRecord> writer = new
SpecificDatumWriter<SpecificRecord>(yourSchema);
DataFileWriter filewriter=new DataFileWriter(writer);
CodecFactory codec = CodecFactory.deflateCodec(9);
filewriter.setCodec(codec);
filewriter.create(yourSchema,out);
encoder = EncoderFactory.get().binaryEncoder(out, encoder);
filewriter.append(fooObj);
filewriter.append(barObj);
filewriter.append(barObj2);
OutputStream outstream=new
FileOutputStream("/somefolder/somefile.avro");
out.writeTo(outstream);
this code works, but now I have an issue with reading the file....
When I read the file, I can only see the first datum in the union. I know that
all of the datums were written to the file because of the size of the file, but
I can't read all of the datums.
Here is my code to read the union file.
Schema yourSchema=Schema.parse(new File("/somefolder/someschema.avro"));
DatumReader<SpecificRecord> datumreader=new
SpecificDatumReader<SpecificRecord>(yourSchema);
DataFileReader reader=new DataFileReader(new
File("/somefolder/somefile.avro"),datumreader);
if(reader.hasNext()){
SpecificRecord result=(SpecificRecord) reader.next();
System.out.println(result.getClass());
}
Not sure if I have a problem with how I created the file or how I am reading
the file....
Any ideas?
________________________________
From: Vyacheslav Zholudev [[email protected]]
Sent: Monday, August 08, 2011 12:52 PM
To: [email protected]
Subject: Re: Java Example of writing a union
I'm assuming for now that you are using a specific writer and you have a union
schema with two records FOO and BAR (you should get two classes FOO and BAR
generated by avro tools):
FOO fooObj = ....
BAR barObj = ....
BAR barObj2 = ....
ByteArrayOutputStream out = new ByteArrayOutputStream();
DatumWriter<GenericRecord> writer = new
SpecificDatumWriter<Record>(yourSchema);
encoder = EncoderFactory.get().binaryEncoder(out, encoder);
writer.write(fooObj, encoder);
writer.write(barObj, encoder);
writer.write(barObj2, encoder);
encoder.flush();
out.close();
Does it make sense?
Vyacheslav
On Aug 8, 2011, at 3:53 PM, Sam Poole wrote:
Does anybody have an example of writing a file that uses a union schema? I
am having problems trying to write a file that uses a union schema because
once I set the schema, I can't add an individual datum because it is not
part of a union.
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