[AVRO-1614] Always getting a value...

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.8.0
• Component/s: java
• Labels: java
• Release Note: [JAVA] Builders can now hold Builder instances of sub schemas.
• Assignee: Niels Basjes
• Reporter: Niels Basjes
• Created: 27/Nov/14 15:36
• Updated: 28/Jan/17 10:10
• Resolved: 17/Dec/14 23:08

Description

Sometimes the Avro structure becomes deeply nested.
If in such a scenario you want to be able to set a specific value deep in this tree you want to do this:

public void setSomething(String value) {
    myStruct
            .getFoo()
            .getBar()
            .getOne()
            .getOther()
            .setSomething(value);
}

The 'problem' I ran into is that any of the 4 get methods can return a null value so the code I have to write is really huge.
For every step in this method I have to build null checks and create the underlying instance if it is null.
I already started writing helper methods to do this for parts of my tree.

To solve this in a way that makes this code readable I came up with the following which I want to propose to you guys (before I start working on a patch).

My idea is to generate a new 'get' method in addition to the existing normal get method for the regular instance of the class.

So in addition to the

public Foo getFoo() {
    return foo;
}

I propose to generate something like this as well in the cases where this is a type of structure that you may want to traverse as shown in the example.

public Foo getAlwaysFoo() {
    if (foo == null) {
        setFoo(Foo.newBuilder().build());
    }
    return foo;
}

This way the automatically created instance immediately has all the defaults I have defined.

Assuming this naming my code will be readable because it will look like this:

public void setSomething(String value) {
    myStruct
            .getAlwaysFoo()
            .getAlwaysBar()
            .getAlwaysOne()
            .getAlwaysOther()
            .setSomething(value);
}