Hi devs,
This tweet x.com prompted me to check our documented practice for deprecated and I’ve noticed that we don’t have a best practice documented for @Deprecated on https://dev.xwiki.org/xwiki/bin/view/Community/CodeStyle/JavaCodeStyle/, so here’s a proposal:
Before we move to Java 9+
Rules:
- Always use both
@Deprecatedannotation and the@deprecatedjavadoc tag. - In the
@deprecatedjavadoc tag, always specify since WHICH version it’s deprecated, and WHAT should be used instead. Also explain WHY it’s deprecated.
Examples:
- Good:
- Couldn’t find any example in xwiki-platform! It should specify the 3 elements (version, what, why).
- Partially good (missing WHY):
/** * The hierarchy of Entity Types. * * @deprecated since 10.6RC1, use {@link EntityType#getAllowedParents()} instead */ @Deprecated Map<EntityType, List<EntityType>> PARENT_TYPES = new EnumMap<EntityType, List<EntityType>>(EntityType.class) - Bad (missing version):
/** * @return the first form contained in this section. * @deprecated this method can be ambiguous since an administration section page might contain several forms. * The method {@link #getFormContainerElement(String)} should be used instead. */ @Deprecated public FormContainerElement getFormContainerElement() { return new FormContainerElement(this.formContainer); } - Bad:
@Deprecated public class i18n
After we move to Java 9
Rules:
- Same idea of the 3 elements that must be specified.
- However the
@Deprecatedannotation now support 2 parameters and they must both be used withforRemovalalways set totrueandsinceshould specify the version. - The javadoc tag must still be there to explain the WHY and the WHAT to use.
Good example:
public class Worker {
/**
* Calculate period between versions
* @deprecated This method is no longer acceptable to compute time between versions because...
* Use {@link Utils#calculatePeriod(Machine)} instead.
*
* @param machine instance
* @return computed time
*/
@Deprecated(since = "4.5", forRemoval = true)
public int calculate(Machine machine) {
return machine.exportVersions().size() * 10;
}
}
WDYT?
Thanks