I've had some issues using builders in the past: building a new object which has required fields in the schema (the type is not a union with null) but that field doesn't specify a default value.
I realize the above is a corner case, but the schemas I've been given are poorly designed, so I had to work around it. When a default value is not specified and a field is optional, will a builder for a brand new object set the value to null in the Java object? On Feb 19, 2014 5:44 PM, "Lewis John Mcgibbney" <lewis.mcgibb...@gmail.com> wrote: > +1 we do this in Gora. > Please note that there are some overheads with using the builders... > "namely Avro objects can be created either by invoking a constructor > directly or by using a builder. Unlike constructors, builders will > automatically set any default values specified in the schema. Additionally, > builders validate the data as it set, whereas objects constructed directly > will not cause an error until the object is serialized. However, using > constructors directly generally offers better performance, as builders > create a copy of the datastructure before it is written." > > Please see > http://avro.apache.org/docs/current/gettingstartedjava.html#Creating+Users > > hth > Lewis > > > On Wed, Feb 19, 2014 at 5:39 PM, Christophe Taton <ta...@wibidata.com>wrote: > >> Hi, >> I'd suggest using the record builders to construct your records: record >> builders will initialize fields with their default values if you don't set >> them. >> C. >> >> >> On Wed, Feb 19, 2014 at 9:07 AM, Gary Steelman <gary.steelma...@gmail.com >> > wrote: >> >>> Hey Wai, >>> >>> Good question. I've had that problem recently too. My solution has been >>> to set the missing field to a known default value in my code before I try >>> to serialize an object. That is, if some integer is required by the schema, >>> I do a check on my object. >>> >>> if (myObject.value == null) {myObject.value = -1;} >>> >>> But then you have to do this for all fields in the schema which aren't >>> optional. And that's kind of a pain. It'd be kind of nice if the writer >>> also used the default value from the schema for writing. >>> >>> Thanks, >>> Gary >>> On Feb 19, 2014 10:42 AM, "Wai Yip Tung" <w...@tungwaiyip.info> wrote: >>> >>>> In the schema we can define a "default" value. It is used as default >>>> when reading. If the field is missing from the data when we write, it >>>> results in an error. Is there a counterpart of "default" in writing so that >>>> if the field is missing, the writer just fill in the default value? >>>> >>>> Wai Yip >>>> >>> >> > > > -- > *Lewis* >
