request for java.util.UUID support

[The Alchemist]

It would be cool to automatically support java.util.UUID fields.

Currently, I use this:

public class UUIDConstructor extends Constructor {
    public UUIDConstructor() {
        yamlClassConstructors.put(NodeId.scalar, new UUIDConstruct());
    }

    class UUIDConstruct extends Constructor.ConstructScalar {
        @Override
        public Object construct(Node nnode) {
            if (nnode.getTag().equals(Tag.STR)) {
                Construct dateConstructor = yamlConstructors.get(Tag.STR);
                String date = (String) dateConstructor.construct(nnode);
                try {
                    return UUID.fromString(date);
                } catch (IllegalArgumentException e) {
                    return super.construct(nnode);
                }
            } else {
                return super.construct(nnode);
            }
        }

    }
}

Thanks!

[Andrey Somov]

Can you please be more specific when you say "automatically support java.util.UUID" ? UUID is not defined in the YAML 1.1 specification.

Your solution is good enough to be used. You may also check Implicit types in the documentation.

[The Alchemist]

@@asomov : What I mean by "automatically support java.util.UUID" is this:

If my YAML looks like this:

uuid: de305d54-75b4-431b-adb2-eb6b9e546014

...and the Java bean looks like this:

class Bean {
    private java.util.UUID uuid;
    /* insert setter and getter for 'uuid' here */
}

then the marshalling/unmarshalling should automatically work. It currently doesn't because java.util.UUID doesn't have a constructor that accepts a java.lang.String, and you have to use the java.util.UUID.fromString() method.

I hope that clears things up. I also realized that that variable called 'date' should be called 'uuid' in the example above. :)

[Andrey Somov]

I think this is a very valid point. But it should be wider: how to provide a factory method for a known class to create instances from scalars. Let us see what we can do. Do you have a proposal how the API may be adapted ?

[The Alchemist]

@asomov : I don't have a proposal for an API (designing a good API is hard), but I personally like the way Jackson handles this kind of situation (http://wiki.fasterxml.com/JacksonHowToCustomDeserializers).

[Andrey Somov]

Can you please test it the latest snapshot (1.17-SNAPSHOT)?

It should be fixed.

This JavaBean: https://bitbucket.org/asomov/snakeyaml/src/e93c852a86cbc243a792f3b5245af56d7bf0a762/src/test/java/org/yaml/snakeyaml/issues/issue306/BeanWithId.java?at=default&fileviewer=file-view-default

can be create with this YAML:

value: 14
id: 7f511847-781a-45df-9c8d-1e32e028b9b3

See the test: https://bitbucket.org/asomov/snakeyaml/src/e93c852a86cbc243a792f3b5245af56d7bf0a762/src/test/java/org/yaml/snakeyaml/issues/issue306/UuidSupportTest.java?at=default&fileviewer=file-view-default

[The Alchemist]

@asomov : sorry i don't know when I'll get the chance to try this next.

[Andrey Somov]

Fix issue 306: UUID support is complete

→ <<cset 8939e0aa430d>>

[Andrey Somov]

The test has examples for JavaBeans and for implicit tag: https://bitbucket.org/asomov/snakeyaml/src/tip/src/test/java/org/yaml/snakeyaml/issues/issue306/UuidSupportTest.java

It will be delivered in version 1.17