how was string_databag generated?
2013/3/19 Dan DeCapria, CivicScience <[email protected]> > Expanding upon this, the following use case's Schema Object can be resolved > from inputs: > > String string_databag = "{(a,(b,d),f)}"; > String string_schema = > "b1:bag{t1:tuple(a:chararray,t2:tuple(b:chararray,d:long),f:long)}"; > Schema schema = Utils.getSchemaFromString(string_schema); > > Next step is to resolve a DataBag Object from String string_databag and the > Schema Object. > > -Dan > > On Tue, Mar 19, 2013 at 9:37 AM, Dan DeCapria, CivicScience < > [email protected]> wrote: > > > Thank you for your reply. > > > > The problem is I cannot find a methodology to go from a String > > representation of a complex data type to a nested Object of pig > DataTypes. > > I looked over the pig 0.10.1 docs, but cannot find a way to go from > String > > and Schema to pig DataType Object. > > > > For context, I am generating these Strings for my own JUnit testing of > > other UDFs. Currently, for complex types, I have to generate each > nesting > > from Tuple and DataBag factories, append data, and next them manually. > For > > larger unit tests, this process becomes unwieldy (hundreds of lines per > > method, non-dynamic), and it would be much simpler to go directly from a > > String and a Schema to a DataBag Object for UDF testing (few lines of > code, > > easily modifiable). > > > > -Dan > > > > > > On Mon, Mar 18, 2013 at 6:31 PM, Jonathan Coveney <[email protected] > >wrote: > > > >> Why not just use PigStorage? This is essentially what it does. It saves > a > >> bag as text, and then loads it again. > >> > >> I suppose the question becomes: why do you need to do this? > >> > >> > >> 2013/3/18 Dan DeCapria, CivicScience <[email protected]> > >> > >> > In Java, I am trying to convert a DataBag from it's String > >> representation > >> > with its schema String to a valid DataBag Object: > >> > > >> > String databag_string = "{(apples,1024)}"; > >> > String schema_string = "b1:bag{t1:tuple(a:chararray,b:long)}"; > >> > > >> > I've tried implementing something along the lines of this, but I > believe > >> > it's in the wrong direction, and then I get stuck: > >> > > >> > String[] aliases = {"b1", "t1", "a", "b"}; > >> > byte[] types = {DataType.BAG, DataType.TUPLE, > >> DataType.CHARARRAY, > >> > DataType.LONG}; > >> > List<Schema.FieldSchema> fsList = new > >> > ArrayList<Schema.FieldSchema>(); > >> > for (int i = 0; i < aliases.length; i++) { > >> > fsList.add(new Schema.FieldSchema(aliases[i], types[i])) ; > >> > } > >> > Schema origSchema = new Schema(fsList); > >> > ResourceSchema rsSchema = new ResourceSchema(origSchema); > >> > Schema genSchema = Schema.getPigSchema(rsSchema); > >> > ResourceSchema.ResourceFieldSchema[] rfschema = > >> > rsSchema.getFields(); > >> > ... lost here, maybe Utf8StorageConverter c = new > >> > Utf8StorageConverter(); ??? > >> > > >> > > >> > An ideal process would be along the lines of: > >> > > >> > DataBag d = BagFactory.getInstance().newDefaultBag(); > >> > d.something(databag_string, schema_string); // ??? no idea what > this > >> > process could be > >> > d.toString().equals(databag_string) == true. > >> > > >> > Thanks, -Dan > >> > > >> > > > > > > > > -- > > Dan DeCapria > > CivicScience, Inc. > > Senior Informatics / DM / ML / BI Specialist > > > > > > -- > Dan DeCapria > CivicScience, Inc. > Senior Informatics / DM / ML / BI Specialist >
