View source for Aether/New and Noteworthy

This page provides the release notes and change log for Aether. Besides linking to the Bugzilla issues resolved for a given version,
we call out significant changes and new functionality here.

== 1.1.0 (NOT-YET-RELEASED) ==

See our issue tracker for a list of [https://bugs.eclipse.org/bugs/buglist.cgi?resolution=FIXED&query_format=advanced&product=Aether&target_milestone=1.1.0 resolved issues in 1.1.0].

== 1.0.1 (2014-11-11) ==

See our issue tracker for a list of [https://bugs.eclipse.org/bugs/buglist.cgi?resolution=FIXED&query_format=advanced&product=Aether&target_milestone=1.0.1 resolved issues in 1.0.1].

This release contains small bug fixes and addresses an OSGi-related issue for the Eclipse Mars release.


== 1.0.0 (2014-05-21) ==

See our issue tracker for a list of [https://bugs.eclipse.org/bugs/buglist.cgi?resolution=FIXED&query_format=advanced&product=Aether&target_milestone=1.0.0 resolved issues in 1.0.0].

Our graduation release from the incubator, yay!

=== Nested Dependencies for Ant Tasks ===

The <tt>&lt;dependencies&gt;</tt> elements of the Aether Ant Tasks can now be nested, allowing users to assemble dependency sets from smaller sets and enabling reuse
of those smaller dependency sets.

=== Removal of Plexus Support ===

(Most of) the explicit support for the legacy Plexus IoC framework has been removed from Aether's components. However, applications that use the Plexus shim
provided by Eclipse Sisu should not even notice this change given that plain JSR-330 components are interoperable with Plexus components.


== 0.9.1 (2014-04-01) ==

See our issue tracker for a list of [https://bugs.eclipse.org/bugs/buglist.cgi?resolution=FIXED&query_format=advanced&product=Aether&target_milestone=0.9.1 resolved issues in 0.9.1].

This maintenance release contains no code changes and merely addresses issues with the manifests of the OSGi bundles.
And given the lack of any code changes, there is no corresponding 0.9.1 release of the Aether Ant Tasks, 0.9.0 is still their latest version.

== 0.9.0 (2014-03-01) ==

See our issue tracker for a list of [https://bugs.eclipse.org/bugs/buglist.cgi?resolution=FIXED&query_format=advanced&product=Aether&target_milestone=0.9.0 resolved issues in 0.9.0].

There have been no significant changes since the last milestone. It is simply a release that has undergone the Eclipse release review process.


== 0.9.0.M4 (2014-01-06) ==

See our issue tracker for a list of [https://bugs.eclipse.org/bugs/buglist.cgi?resolution=FIXED&query_format=advanced&product=Aether&target_milestone=0.9.0.M4 resolved issues in 0.9.0.M4].

=== Transparent WebDAV Support ===

The <tt>aether-transport-http</tt> introduced in the last milestone has been extended to detect WebDAV servers and issue MKCOL requests
to create any missing parent directories during uploads. Remote repositories backed by WebDAV servers are specified via ordinary <tt>http:</tt>/<tt>https:</tt> URLs,
i.e. there is no special URL scheme required to enable the new WebDAV support.

=== Customizable Checksum Policies ===

In previous versions, the supported checksum policies and their specific behavior was hard-coded in each repository connector. As of this milestone,
the specifics of checksum policies are controlled centrally by a <tt>ChecksumPolicyProvider</tt>. The module <tt>aether-impl</tt> ships with a default
implementation of this new component that realizes the well-known "fail", "warn" and "ignore" policies. By replacing this component with their own
implementation, integrators may provide their own checksum policies.

=== Dependency Cycles ===

Previously, the process building the dependency graph has been silently tolerating cyclic dependencies. The presence of a dependency cycle usually
indicates an issue with the component composition that should be fixed. This new version records any detected dependency cycle
in the <tt>CollectResult</tt>, thereby allowing applications to report the issue to the end user.



== 0.9.0.M3 (2013-07-31) ==

See our issue tracker for a list of [https://bugs.eclipse.org/bugs/buglist.cgi?resolution=FIXED&query_format=advanced&product=Aether&target_milestone=0.9.0.M3 resolved issues in 0.9.0.M3].

=== Version Ranges ===

To ease working with version ranges, the version syntax recognized by <tt>GenericVersionScheme</tt> has been extended to recognize
the case-insensitive tokens "min" and "max". These tokens can be used as the last segment of a version string to denote the minimum
and maximum value for that segment. For example, using the new syntax, the requirement "depend on version 2.x" translates to the version
range "[2.min, 2.max]". Unlike the common attempt to achieve this using "[2.0, 3.0)", the new syntax properly includes "2.0-SNAPSHOT"
and excludes "3.0-rc-1". Last but not least, a range of the form "[M.N.min, M.N.max]" can be specified more compact as "[M.N.*]".

Furthermore, a new hook named <tt>VersionFilter</tt> has been added to the dependency collection process. This hook allows clients
to control which of the available versions matching a range are actually acceptable for the dependency graph. The <tt>aether-util</tt>
module ships with a ready-made <tt>ContextualSnapshotVersionFilter</tt> that clients might find useful.

=== Transporters ===

This release introduces a new <tt>TransporterFactory</tt> SPI that simplifies plugging in support for various transport protocols required
to access remote repositories. The transporters provided by the new factory extension provide transport layer services for the existing
repository connector infrastructure. More specifically, the new module <tt>aether-connector-basic</tt> provides a repository connector that
employs these new transporters.

To demonstrate the new transporter SPI and simplify the codebase, most of the original repository connectors have been reworked into
transporters. Consumers updating to this release need to account for the following changes when declaring dependencies:

* <tt>aether-connector-basic</tt> is required as dependency to employ any of the new transporters
* <tt>aether-connector-asynchttpclient</tt> is superseded by <tt>aether-transport-http</tt>
* <tt>aether-connector-file</tt> is superseded by <tt>aether-transport-file</tt>
* <tt>aether-connector-wagon</tt> is superseded by <tt>aether-transport-wagon</tt>

As a bonus, the module <tt>aether-transport-classpath</tt> has been introduced to enable resolving artifacts from the classpath.

Note: As part of this refactoring, the contract for repository connectors regarding the transfer listener has been revised. Instead of a global listener,
a transfer specific listener is to be notified (cf. the updated API docs for <tt>RepositoryConnector</tt>).

=== Repository Layouts ===

Just like with transport protocols, implementing custom repository layouts has been simplified by introduction of a <tt>RepositoryLayoutFactory</tt>
SPI. These factories can be employed by repository connectors to constructs URIs for uploads/downloads. The already mentioned <tt>aether-connector-basic</tt>
makes use of the new extension to provide a flexible way for accessing remote repositores. The module <tt>aether-impl</tt> provides a
concrete implementation of such a layout factory for Maven's default layout.

=== Ant Tasks ===

This milestone also features our first release of the Aether Ant Tasks, enabling users of Apache Ant to utilize Maven repositories for dependency resolution
and artifact deployment. Please note that the current version of the Aether Ant Tasks only supports <tt>file:</tt>, <tt>http:</tt> and <tt>https:</tt> repositories.


== 0.9.0.M2 (2013-02-19) ==

This is the first release of Eclipse Aether for which a compatible <tt>maven-aether-provider</tt> exists. Said component
enables users to access Maven repositories and can be obtained from the Central repository using these coordinates:

  <dependency>
    <groupId>org.apache.maven</groupId>
    <artifactId>maven-aether-provider</artifactId>
    <version>3.1.0-alpha-1</version>
  </dependency>

See our issue tracker for a list of [https://bugs.eclipse.org/bugs/buglist.cgi?resolution=FIXED&query_format=advanced&product=Aether&target_milestone=0.9.0.M2 resolved issues in 0.9.0.M2].

=== Conflict Resolution ===

In previous versions, the <tt>JavaEffectiveScopeCalculator</tt> and <tt>NearestVersionConflictResolver</tt> were responsible to
resolve scope and version conflicts and deliver a cleaned up dependency tree. However, the separation of scope and version handling
in two isolated dependency graph transformers suffers from a conceptual flaw and caused subtle bugs regarding the effective scope
of dependencies. The mentioned classes have been replaced with the new <tt>ConflictResolver</tt> transformer. This new transformer
handles both version and scope conflicts and provides hooks to customize the conflict resolution. To achieve the same kind of
conflict resolution as offered previously by the broken transformers, use
<tt>new ConflictResolver( new NearestVersionSelector(), new JavaScopeSelector(), new SimpleOptionalitySelector(), new JavaScopeDeriver() )</tt>.

The <tt>SimpleOptionalitySelector</tt> hints at another significant fix: The optional flag now gets similar processing during
transitive dependency resolution as the scope, i.e. the effective optional flag is subject to the optionality of ancestor nodes and conflict
resolution. For instance, transitive dependencies of optional dependencies are now considered optional as well.

As detailed in the API docs of the <tt>ConflictResolver</tt>, the new graph transformer also supports a verbose mode. This mode
can be used to obtain a dependency tree which resembles the dependency hierarchy tab in [http://www.eclipse.org/m2e/ m2e].

Last but not least, early feedback suggests the new conflict resolution code executes significantly faster than the old code.

=== Offline Mode ===

Is a remote repository with the URL "file:/whatever" accessible in offline mode? To allow clients to answer this question appropriately,
the internal implementation has been refactored to centralize the offline decision in a new component called <tt>OfflineController</tt>.
The default implementation of this component supports two configuration properties to address common requirements:

* <tt>aether.offline.protocols</tt>: Comma-separated list of protocols which are accessible even in offline mode, e.g. "file"
* <tt>aether.offline.hosts</tt>: Comma-separated list of hostnames which are accessible even in offline mode, e.g. "localhost"

=== Pre-managed Dependency Attributes ===

Previously, the methods <tt>DependencyNode.getPremanaged*()</tt> could be used to obtain the version and scope of a dependency before
it was updated by dependency management. To reduce memory consumption for ordinary dependency resolution, these methods have been
removed and their backing data is no longer recorded for each node by default. The pre-managed attributes can still be obtained via
a new configuration property, see <tt>DependencyManagerUtils</tt> for details regarding its usage.

=== P2 Update Site ===

Starting with this milestone, we provide a P2 update site for Aether Core, powered by [http://www.eclipse.org/tycho/ Tycho].
This site provides two features, one for the binaries and another one for the sources. You'll find the relevant links on the download page.


== 0.9.0.M1 (2012-10-03) ==

This is the first release of Aether since its migration to the Eclipse Foundation. As such the items listed below indicate
changes compared to the previous Sonatype Aether codebase.

''Note:'' There is currently no released version of the <tt>maven-aether-provider</tt> that builds upon this release of Aether Core
so this milestone release is not of direct interest to users seeking access to Maven repositories. Early adopters interested
in evaluating the new codebase can find an updated <tt>maven-aether-provider</tt> at https://github.com/bentmann/maven-3.

See our issue tracker for a list of [https://bugs.eclipse.org/bugs/buglist.cgi?resolution=FIXED&query_format=advanced&product=Aether&target_milestone=0.9.0.M1 resolved issues in 0.9.0.M1].

=== Namespace org.eclipse.aether ===

All code has been moved into the package <tt>org.eclipse.aether</tt> and sub packages. Likewise, the group ID of the artifacts
deployed to the Central Repository has changed to <tt>org.eclipse.aether</tt>.

=== Clean up of API ===

Besides the new package namespace, the API has been changed in some places to ease usage and maintenance. The list below is not
exhaustive but focuses on changes where updates to client code are not obvious:

* <tt>TransferEvent.RequestType.GET_EXISTENCE</tt> was introduced to allow transfer listeners to distinguish between actual downloads and mere existence checks.
* <tt>FilteredRepositorySystemSession</tt> was removed and its usages should be replaced with <tt>DefaultRepositorySystemSession</tt> and its copy constructor.
* The properties <tt>transferErrorCachingEnabled</tt> and <tt>notFoundCachingEnabled</tt> of <tt>RepositorySystemSession</tt> have been replaced by <tt>ResolutionErrorPolicy</tt>, <tt>SimpleResolutionErrorPolicy</tt> provides a stock implementation.
* The properties <tt>ignoreMissingArtifactDescriptor</tt> and <tt>ignoreInvalidArtifactDescriptor</tt> of <tt>RepositorySystemSession</tt> have been replaced by <tt>ArtifactDescriptorPolicy</tt>, <tt>SimpleArtifactDescriptorPolicy</tt> provides a stock implementation.
* <tt>Authentication</tt> was remodeled into an interface, the new <tt>AuthenticationBuilder</tt> provides a way to obtain a stock implementation.
* <tt>RemoteRepository</tt> instances have been made immutable, <tt>RemoteRepository.Builder</tt> assists in their instantiation.

=== OSGi-enabled Manifests ===

Thanks to a contributor, the JAR manifests have been extended with attributes to support use of Aether in an OSGi container.
Providing an update site for Aether is an unresolved todo in our issue tracker, contributions welcome.

=== Support for JSR-330 ===

The components making up the implemenation of Aether have been enriched with <tt>javax.inject</tt> annotations to support wiring
by a JSR-330 compliant container. The class <tt>AetherModule</tt> helps to set up bindings for the popular Guice container. Likewise,
the JARs are equipped with Sisu index files to support efficient component discovery when using [http://www.eclipse.org/sisu/ Sisu].

[[Category:Aether]]