Refactoring of all `StringConverter`s and their tests. General notes: * The documentation language has been unified and `null` parameter rules have been documented. * Tests have been cleaned up in the vein of https://github.com/openjdk/jfx/pull/1759 and unneeded `@BeforeAll`s were removed. * Internal fields were made `private final` to guarantee immutability.
Incremental commits are provided for easier reviewing: ### Parent classes * `StringConverter`: updated documentation * `BaseStringConverter`: a new internal class that implements repeated code from converter implementations and serves as an intermediate superclass. It does empty and `null` string checks that are handled uniformly, except for `DefaultStringConverter`, which has a different formatting mechanism. ### Primitive-related converters * All primitive (wrapper) converters also document their formatting and parsing mechanism since these are "well-established". ### Format converter * Checked for `null` during constriction time to avoid runtime NPEs. * There is no test class for this converter. A followup might be desirable. * A followup should deprecate for removal `protected Format getFormat()` (as in [JDK-8314597](https://bugs.openjdk.org/browse/JDK-8314597) and [JDK-8260475](https://bugs.openjdk.org/browse/JDK-8260475). ### Number and subclasses converters * The intermediate `locale` and `pattern` fields were removed (along with their tests). The class generated a new formatter from these on each call. This only makes sense for mutable fields where the resulting formatter can change, but here the formatter can be computed once on construction and stored. * The only difference between these classes is a single method for creating a format from a `null` pattern, which was encapsulated in the `getSpecializedNumberFormat` method. * The terminally deprecated `protected NumberFormat getNumberFormat()` was removed. Can be split to its own issue if preferred. In my opinion, it shouldn't exist even internally since testing the internal formatter doesn't help. The only tests here should be for to/from strings, and these are lacking. A followup can be filed for adding more conversion tests. ### Date/Time converters * Added a documentation note advising users to use the `java.time` classes instead of the old `Date` class. * As with Number converters, only the `dateFormat` field was kept, which is created once on construction instead of on each call. * As with Number converters, the `getSpecialziedDateFormat` method is the only difference between the classes. * As with Number converters, `protected DateFormat getDateFormat()` has been removed from the subclasses and shouldn't exist internally either in my opinion. ### LocalDate/Time converters * The structure of these classes is different from the above 2 groups since there is no subclassing. Instead, the Date and Time converters used the DateTime converter's `LdtConverter` implementation by passing their class type, which is not a good design. Instead, an internal superclass `BaseTemporalStringConverter<T extends Temporal>` was introduced along with its shim. * The code that fixes the 4 year pattern, `fixFourDigitYear`, is now checked *before* creating a formatter, avoiding unneeded formatter creations. * As above, only the `parser` and `formatter` fields were kept. * As above, the `getLocalizedFormatter` and `getTemporalQuery()` methods are the only differences between the subclasses. * As above, testing the formatter and parser isn't useful in my opinion. ------------- Commit messages: - LocalDate/Time converters - Date/Time converters - Number and subclasses converters - Format converter - Primitive-related converters - Parent classes Changes: https://git.openjdk.org/jfx/pull/1880/files Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1880&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8250802 Stats: 2915 lines in 50 files changed: 464 ins; 1537 del; 914 mod Patch: https://git.openjdk.org/jfx/pull/1880.diff Fetch: git fetch https://git.openjdk.org/jfx.git pull/1880/head:pull/1880 PR: https://git.openjdk.org/jfx/pull/1880
