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.artifactResolver.simpleLrmInterop boolean Enable interop with Simple LRM. Ignored when RRF used. false no
aether.artifactResolver.postProcessor.trustedChecksums boolean Enable trustedChecksums resolver post processor. false no
aether.artifactResolver.postProcessor.trustedChecksums.checksumAlgorithms String Comma-separated list of checksum algorithms with which trustedChecksums should operate (validate or record). "SHA-1" no
aether.artifactResolver.postProcessor.trustedChecksums.failIfMissing boolean Makes trustedChecksums fail validation if a trusted checksum for an artifact is missing. false no
aether.artifactResolver.postProcessor.trustedChecksums.record boolean Makes trustedChecksums calculate and record checksums. false no
aether.artifactResolver.postProcessor.trustedChecksums.snapshots boolean Enables or disables snapshot processing in trustedChecksums post processor. false 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,.sigstore 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" yes
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.basic.parallelPut boolean Enables or disables parallel PUT processing (parallel deploys) on basic connector globally or per remote repository. When disabled, connector behaves exactly as in Maven 3.8.x did: GETs are parallel while PUTs are sequential. true yes
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.bind.address String Set the outgoing interface (globally or per remote repository). Valid values are local accessible IP addresses or host names. The default will use the system's default route. Invalid addresses will result in HttpTransport creation failure. - 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.connectionMaxTtl int Total time to live in seconds for an HTTP connection, after that time, the connection will be dropped (no matter for how long it was idle). 300 yes
aether.connector.http.credentialEncoding String The encoding/charset to use when exchanging credentials with HTTP servers. "ISO-8859-1" yes
aether.connector.http.expectContinue boolean Whether to use expect/continue handshake during PUTs. Some broken HTTP servers needs this disabled. true 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.http.maxConnectionsPerRoute int The maximum concurrent connections per route HTTP client is allowed to use. 50 yes
aether.connector.http.preemptiveAuth boolean Should HTTP client use preemptive-authentication for all HTTP verbs (works only w/ BASIC). By default is disabled, as it is considered less secure. false yes
aether.connector.http.preemptivePutAuth boolean Should HTTP client use preemptive-authentication for HTTP PUTs only (works only w/ BASIC). By default is enabled (same as Wagon). true yes
aether.connector.http.retryHandler.count int The maximum number of times a request to a remote HTTP server should be retried in case of an error. 3 yes
aether.connector.http.retryHandler.interval long The initial retry interval in milliseconds, if server responds with “too many requests”. Is multiplied by 1, 2,.. on each try. If server emits Retry-After header, it is obeyed instead of this value. 5000 yes
aether.connector.http.retryHandler.intervalMax long The retry interval maximum in milliseconds, after request should be given up (5 minutes). 300000 yes
aether.connector.http.retryHandler.name String The name of retryHandler, supported values are “standard”, that obeys RFC-2616, regarding idempotent methods, and “default” that considers requests w/o payload as idempotent. standard yes
aether.connector.http.retryHandler.requestSentEnabled boolean Set to true if it is acceptable to retry non-idempotent requests, that have been sent. false yes
aether.connector.http.retryHandler.serviceUnavailable String Comma separated list of HTTP codes that should be handled as “too many requests”. "429,503" yes
aether.connector.http.reuseConnections boolean Should HTTP client reuse connections (in other words, pool connections) or not? true yes
aether.connector.http.supportWebDav boolean If enabled, transport makes best effort to deploy to WebDAV server. This mode is not recommended, better use real Maven Repository Manager instead. false yes
aether.connector.http.useSystemProperties boolean If enabled, underlying Apache HttpClient will use system properties as well to configure itself (typically used to set up HTTP Proxy via Java system properties). See HttpClientBuilder for used properties. This mode is not recommended, better use documented ways of configuration instead. false yes
aether.connector.https.cipherSuites String Comma-separated list of Cipher Suites which are enabled for HTTPS connections. - (no restriction) no
aether.connector.https.securityMode String Using this flag resolver may set the “security mode” of HTTPS connector. Any other mode than ‘default’ is NOT MEANT for production, as it is inherently not secure. Accepted values: “default”, “insecure” (ignore any kind of certificate validation errors and hostname validation checks). "default" yes
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.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.dependencyCollector.bf.threads or maven.artifact.threads int Number of threads to use for collecting POMs and version ranges in BF collector. 5 no
aether.dependencyCollector.pool.artifact String Flag controlling interning data pool type used by dependency collector for Artifact instances, matters for heap consumption. By default uses “weak” references (consume less heap). Using “hard” will make it much more memory aggressive and possibly faster (system and Java dependent). Supported values: "hard", "weak". "weak" no
aether.dependencyCollector.pool.dependency String Flag controlling interning data pool type used by dependency collector for Dependency instances, matters for heap consumption. By default uses “weak” references (consume less heap). Using “hard” will make it much more memory aggressive and possibly faster (system and Java dependent). Supported values: "hard", "weak". "weak" no
aether.dependencyCollector.pool.descriptor String Flag controlling interning data pool type used by dependency collector for Artifact Descriptor (POM) instances, matters for heap consumption. By default uses “hard” references (consume more heap, but is faster). Using “weak” will make resolver much more memory conservative, at the cost of up to 10% slower collecting dependency speed (system and Java dependent). Supported values: "hard", "weak". "hard" 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.localPrefix String The prefix to use for locally installed artifacts. "installed" no
aether.enhancedLocalRepository.snapshotsPrefix String The prefix to use for snapshot artifacts. "snapshots" no
aether.enhancedLocalRepository.split boolean Whether LRM should split local and remote artifacts. false no
aether.enhancedLocalRepository.splitLocal boolean Whether locally installed artifacts should be split by version (release/snapshot). false no
aether.enhancedLocalRepository.splitRemote boolean Whether cached artifacts should be split by version (release/snapshot). false no
aether.enhancedLocalRepository.splitRemoteRepository boolean Whether cached artifacts should be split by origin repository (repository ID). false no
aether.enhancedLocalRepository.splitRemoteRepositoryLast boolean For cached artifacts, if both splitRemote and splitRemoteRepository are set to true sets the splitting order: by default it is repositoryId/version (false) or version/repositoryId (true) false no
aether.enhancedLocalRepository.remotePrefix String The prefix to use for downloaded and cached artifacts. "cached" no
aether.enhancedLocalRepository.releasesPrefix String The prefix to use for release artifacts. "releases" 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.remoteRepositoryFilter.groupId boolean Enable groupId remote repository filter. false no
aether.remoteRepositoryFilter.groupId.basedir String The basedir path for groupId filter. If relative, resolved against local repository root, if absolute, used as is. ".remoteRepositoryFilters" no
aether.remoteRepositoryFilter.groupId.record boolean Enable recording of groupId filter. false no
aether.remoteRepositoryFilter.groupId.truncateOnSave boolean When recoding session done, should groupId filter truncate (overwrite) the output file with newly recorded data, or, if file exists, load-merge-save it? false no
aether.remoteRepositoryFilter.prefixes boolean Enable prefixes remote repository filter. false no
aether.remoteRepositoryFilter.prefixes.basedir String The basedir path for prefixes filter. If relative, resolved against local repository root, if absolute, used as is. ".remoteRepositoryFilters" 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.basedir.locksDir String The basedir path for file named locks. If relative, resolved against local repository root, if absolute, used as is. ".locks" 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.hashing.depth int The directory depth to “spread” hashes in git-like fashion, integer between 0 and 4 (inclusive). 2 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.retry int Count of retries SyncContext adapter should perform, when obtaining locks. 1 no
aether.syncContext.named.retry.wait long Amount of milliseconds a thread to wait between retries, when obtaining locks. 200 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.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.discriminating.hostname String The hostname to be used with discriminating mapper. Detected with InetAddress.getLocalHost().getHostName() 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.trustedChecksumsSource.sparseDirectory boolean Enable sparseDirectory trusted checksum source. false no
aether.trustedChecksumsSource.sparseDirectory.basedir String The basedir path for sparseDirectory trusted checksum source. If relative, resolved against local repository root, if absolute, used as is. ".checksums" no
aether.trustedChecksumsSource.sparseDirectory.originAware boolean Is trusted checksum source origin aware (factors in Repository ID into path) or not. true no
aether.trustedChecksumsSource.summaryFile boolean Enable summaryFile trusted checksum source. false no
aether.trustedChecksumsSource.summaryFile.basedir String The basedir path for summaryFile trusted checksum source. If relative, resolved against local repository root, if absolute, used as is. ".checksums" no
aether.trustedChecksumsSource.summaryFile.originAware boolean Is trusted checksum source origin aware (factors in Repository ID into path) or not. true 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 settings.xml. For details refer to https://github.com/apache/maven/blob/master/maven-core/src/main/java/org/apache/maven/internal/aether/DefaultRepositorySystemSessionFactory.java.