Configuration Options

Option Type Description Default Value Supports Repo ID Suffix
aether.artifactResolver.snapshotNormalization boolean It replaces the timestamped snapshot file name with a filename containing the SNAPSHOT qualifier only. This only affects resolving/retrieving artifacts but not uploading those. true no
aether.checksums.omitChecksumsForExtensions String Comma separated list of extensions with leading dot (example .asc) that should have checksums omitted. These are applied to sub-artifacts only. Note: to achieve 1.7.x aether.checksums.forSignature=true behaviour, pass empty string as value for this property. .asc no
aether.checksums.algorithms String Comma separated list of checksum algorithms with which checksums are validated (downloaded) and generated (uploaded). Resolver by default supports following algorithms: MD5, SHA-1, SHA-256 and SHA-512. New algorithms can be added by implementing ChecksumAlgorithmFactory component. "SHA-1,MD5" no
aether.conflictResolver.verbose boolean Flag controlling the conflict resolver’s verbose mode. false no
aether.connector.basic.threads or maven.artifact.threads int Number of threads to use for uploading/downloading. 5 no
aether.connector.classpath.loader ClassLoader ClassLoader from which resources should be retrieved which start with the classpath: protocol. Thread.currentThread().getContextClassLoader() no
aether.connector.connectTimeout long Connect timeout in milliseconds. 10000 yes
aether.connector.http.cacheState boolean Flag indicating whether a memory-based cache is used for user tokens, connection managers, expect continue requests and authentication schemes. true no
aether.connector.http.credentialEncoding String The encoding/charset to use when exchanging credentials with HTTP servers. "ISO-8859-1" yes
aether.connector.http.headers Map<String, String> The request headers to use for HTTP-based repository connectors. The headers are specified using a map of strings mapping a header name to its value. The repository-specific headers map is supposed to be complete, i.e. is not merged with the general headers map. - yes
aether.connector.https.cipherSuites String Comma-separated list of Cipher Suites which are enabled for HTTPS connections. - (no restriction) no
aether.connector.https.protocols String Comma-separated list of Protocols which are enabled for HTTPS connections. - (no restriction) no
aether.connector.perms.fileMode String Octal numerical notation of permissions to set for newly created files. Only considered by certain Wagon providers. - no
aether.connector.perms.dirMode String Octal numerical notation of permissions to set for newly created directories. Only considered by certain Wagon providers. - no
aether.connector.perms.group String Group which should own newly created directories/files. Only considered by certain Wagon providers. - no
aether.connector.persistedChecksums boolean Flag indicating whether checksums which are retrieved during checksum validation should be persisted in the local filesystem next to the file they provide the checksum for. true no
aether.connector.resumeDownloads boolean Whether to resume partially downloaded files if the download has been interrupted. true yes
aether.connector.resumeThreshold long The size in bytes which a partial download needs to have at least to be resumed. Requires aether.connector.resumeDownloads to be true to be effective. 64 * 1024 yes
aether.connector.requestTimeout long Request timeout in milliseconds. 1800000 yes
aether.connector.smartChecksums boolean Flag indicating that instead of comparing the external checksum fetched from the remote repo with the calculated one, it should try to extract the reference checksum from the actual artifact requests’s response headers (several (strategies supported)[included-checksum-strategies.html]). This only works for transport-http transport. true no
aether.connector.userAgent String The user agent that repository connectors should report to servers. "Aether" no
aether.connector.wagon.config Object The configuration to use for the Wagon provider. - yes (must be used)
aether.dependencyCollector.maxCycles int Only up to the given amount cyclic dependencies are emitted. 10 no
aether.dependencyCollector.maxExceptions int Only exceptions up to the number given in this configuration property are emitted. Exceptions which exceed that number are swallowed. 50 no
aether.dependencyCollector.impl String The name of the dependency collector implementation to use: depth-first (original) named df, and breadth-first (new in 1.8.0) named bf. Both collectors produce equivalent results, but they may differ performance wise, depending on project being applied to. Our experience shows that existing df is well suited for smaller to medium size projects, while bf may perform better on huge projects with many dependencies. Experiment (and come back to us!) to figure out which one suits you the better. "df" no
aether.dependencyCollector.bf.skipper boolean Flag controlling whether to skip resolving duplicate/conflicting nodes during the breadth-first (bf) dependency collection process. true no
aether.dependencyManager.verbose boolean Flag controlling the verbose mode for dependency management. If enabled, the original attributes of a dependency before its update due to dependency managemnent will be recorded in the node’s DependencyNode#getData() when building a dependency graph. false no
aether.enhancedLocalRepository.trackingFilename String Filename of the file in which to track the remote repositories. "_remote.repositories" no
aether.interactive boolean A flag indicating whether interaction with the user is allowed. false no
aether.metadataResolver.threads int Number of threads to use in parallel for resolving metadata. 4 no
aether.offline.protocols String Comma-separated list of protocols which are supposed to be resolved offline. - no
aether.offline.hosts String Comma-separated list of hosts which are supposed to be resolved offline. - no
aether.priority.<class> float The priority to use for a certain extension class. class can either be the fully qualified name or the simple name stands for fully qualified class name. If the class name ends with Factory that suffix could optionally be left out. - no
aether.priority.implicit boolean Flag indicating whether the priorities of pluggable extensions are implicitly given by their iteration order such that the first extension has the highest priority. If set, an extension’s built-in priority as well as any corresponding aether.priority.<class> configuration properties are ignored when searching for a suitable implementation among the available extensions. This priority mode is meant for cases where the application will present/inject extensions in the desired search order. false no
aether.snapshotFilter boolean Flag whether the ContextualSnapshotVersionFilter should be forced to ban snapshots. By default, snapshots are only filtered if the root artifact is not a snapshot. false no
aether.syncContext.named.factory String Name of the named lock factory implementing the org.eclipse.aether.named.NamedLockFactory interface. "rwlock-local" no
aether.syncContext.named.nameMapper String Name of name mapper implementing the org.eclipse.aether.internal.impl.synccontext.named.NameMapper interface. "gav" no
aether.syncContext.named.time long Amount of time a synchronization context shall wait to obtain a lock. 30 no
aether.syncContext.named.time.unit long Unit of the lock wait time. "SECONDS" no
aether.syncContext.named.static.name String Lock name for the static name mapper. "static" no
aether.syncContext.named.discriminating.discriminator String A discriminator name prefix identifying a Resolver instance. "sha1('${hostname:-localhost}:${maven.repo.local}')" or "sha1('')" if generation fails no
aether.syncContext.named.redisson.configFile String Path to a Redisson configuration file in YAML format. Read official documentation for details. none or "${maven.conf}/maven-resolver-redisson.yaml" if present no
aether.updateCheckManager.sessionState String Manages the session state, i.e. influences if the same download requests to artifacts/metadata will happen multiple times within the same RepositorySystemSession. If "enabled" will enable the session state. If "bypass" will enable bypassing (i.e. store all artifact ids/metadata ids which have been updates but not evaluating those). All other values lead to disabling the session state completely. "enabled" no

All properties which have yes in the column Supports Repo ID Suffix can be optionally configured specifically for a repository id. In that case the configuration property needs to be suffixed with a period followed by the repository id of the repository to configure, e.g. aether.connector.http.headers.central for repository with id central.

Property Type Conversion

If the value is not given in the target type the following conversions are applied.

From To With
String boolean Boolean.parseBoolean(...)
String int Integer.parseInt(...)
String long Long.parseLong(...)
String float Float.parseFloat(...)

Set Configuration from Apache Maven

To set one of the configuration options from above just use system variables. As system variables only support String values the type conversion mentioned above needs to be leveraged. Sometimes Maven uses different default values than the Maven Resolver itself or tries to extract certain values from the server.xml. For details refer to https://github.com/apache/maven/blob/master/maven-core/src/main/java/org/apache/maven/internal/aether/DefaultRepositorySystemSessionFactory.java.