The Maven coordinate is split in tokens between dots ('`.`'), hyphens ('`-`') and transitions between digits and characters. The separator is recorded and will have effect on the order. A transition between digits and characters is equivalent to a hyphen. Empty tokens are replaced with "`0`". This gives a sequence of version numbers (numeric tokens) and version qualifiers (non-numeric tokens) with "`.`" or "`-`" prefixes.
Splitting and Replacing Examples:
-`1-1.foo-bar1baz-.1` -> `1-1.foo-bar-1-baz-0.1`
Then, starting from the end of the version, the trailing "null" values (`0`, `""`, "`final`", "`ga`") are trimmed. This process is repeated at each remaining hyphen from end to start.
Trimming Examples:
-`1.0.0` -> `1`
-`1.ga` -> `1`
-`1.final` -> `1`
-`1.0` -> `1`
-`1.` -> `1`
-`1-` -> `1`
-`1.0.0-foo.0.0` -> `1-foo`
-`1.0.0-0.0.0` -> `1`
The version order is the `lexicographical order` on this sequence of prefixed tokens, the shorter one padded with enough "null" values with matching prefix to have the same length as the longer one. Padded "null" values depend on the prefix of the other version: 0 for '.', "" for '-'. The prefixed token order is:
- if the prefix is the same, then compare the token:
- Numeric tokens have the natural order.
- Non-numeric tokens ("qualifiers") have the alphabetical order, except for the following tokens which come first in this order:
- "`1-sp-1`" < "`1-ga-1`" = "`1-1`" (trailing "null" values at each hyphen)
- "`1-a1`" = "`1-alpha-1`"
Note: Contrary to what was stated in some design documents, for version order, snapshots are not treated differently than releases or any other qualifier.
-`1.0`: Soft requirement for 1.0. Use 1.0 if no other version appears earlier in the dependency tree.
-`[1.0]`: Hard requirement for 1.0. Use 1.0 and only 1.0.
-`(,1.0]`: Hard requirement for any version <= 1.0.
-`[1.2,1.3]`: Hard requirement for any version between 1.2 and 1.3 inclusive.
-`[1.0,2.0)`: 1.0 <= x <2.0;Hardrequirementforanyversionbetween1.0inclusiveand2.0exclusive.
-`[1.5,)`: Hard requirement for any version greater than or equal to 1.5.
-`(,1.0],[1.2,)`: Hard requirement for any version less than or equal to 1.0 than or greater than or equal to 1.2, but not 1.1. Multiple requirements are separated by commas.
-`(,1.1),(1.1,)`: Hard requirement for any version except 1.1; for example because 1.1 has a critical vulnerability.
Maven picks the highest version of each project that satisfies all the hard requirements of the dependencies on that project. If no version satisfies all the hard requirements, the build fails.
