Change generated constructors so that application code evolves better
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Key: THRIFT-529
URL: https://issues.apache.org/jira/browse/THRIFT-529
Project: Thrift
Issue Type: Improvement
Components: Compiler (Java)
Reporter: Nathan Marz
Priority: Minor
The constructors generated by the Java compiler encourage code that breaks when
the thrift definition changes. For example, it is common to add an optional
field to a pre-existing schema, like:
struct Activity {
1: required i32 id;
2: required i32 type;
3: optional i64 timestamp; //newly added
}
Any code that used the Activity(int, int) constructor will now break.
One option to address this problem is to only generate empty constructors.
However, this makes it cumbersome to create new objects as a line of code is
needed to instantiate each field. A second option is to generate constructors
only for required fields. For example, to create an Activity with a timestamp,
the user would need to do the following:
Activity a = new Acitivity(3,4);
a.set_timestamp(timestamp);
This gracefully handles the addition of optional fields. For the case of adding
a new required field, the constructors would break. Arguably this is desired
behavior since all the code would need to be updated anyway, and this way you
would be getting compile errors instead of runtime validation errors.
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