基于Karaf的项目离线打包与发布
mvn-uri := 'mvn:' [ repository-url '!' ] group-id '/' artifact-id [ '/' [version] [ '/' [type] [ '/' classifier ] ] ] ]repository-url := < rfc2396 uri > ; an url that points to a maven 2 repositorygroup-id := < maven groupId > ; group id of maven artifactartifact-id := < maven artifactId > ; artifact id of maven artifactversion := < maven version > | 'LATEST' | range ; version of maven artifactrange := ( '[' | '(' ) version ',' version ( ')' | ']' )type := < maven type> ; type of maven artifactclassifier := < maven classifier> ; maven artifact classifier

假设项目需要依赖Pax Web的service-0.2.0-SNAPSHOT.jar,对应的Mvn协议示例如下：

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mvn:org.ops4j.pax.web.bundles/service

mvn:org.ops4j.pax.web.bundles/service/LATEST

mvn:org.ops4j.pax.web.bundles/service/0.2.0-SNAPSHOT

mvn:http://repository.ops4j.org/maven2!org.ops4j.pax.web.bundles/service/0.2.0

mvn:file://c:/localRepo!org.ops4j.pax.web.bundles/service/0.2.0 - 从目录中加载

mvn:org.ops4j.pax.web/pax-web-features/3.0.4-SNAPSHOT/xml/features --标识pax-web-features-3.0.4-SNAPSHOT-features.xml构件

协议要点

1）如果版本（version）未指定，将使用默认值“LATEST”，并从可用的Maven元数据（metadata）中解析最新的版本，maven metadata的示例如下：

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<?xml version="1.0" encoding="UTF-8"?><metadata modelVersion="1.1.0">  <groupId>org.ops4j.pax.web</groupId>  <artifactId>pax-web-features</artifactId>  <version>3.0.4-SNAPSHOT</version>  <versioning>    <snapshot>      <timestamp>20131113.170334</timestamp>      <buildNumber>2</buildNumber>    </snapshot>    <lastUpdated>20131113170334</lastUpdated>    <snapshotVersions>      <snapshotVersion>        <extension>pom</extension>        <value>3.0.4-20131113.170334-2</value>        <updated>20131113170334</updated>      </snapshotVersion>      <snapshotVersion>        <classifier>features</classifier>        <extension>xml</extension>        <value>3.0.4-20131113.170334-2</value>        <updated>20131113170334</updated>      </snapshotVersion>      <snapshotVersion>        <classifier>jettyconfig</classifier>        <extension>xml</extension>        <value>3.0.4-20131113.170334-2</value>        <updated>20131113170334</updated>      </snapshotVersion>    </snapshotVersions>  </versioning></metadata>

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2）如果version是SNAPSHOT版本，则采用与maven一致的策略来解析SNAPSHOT版本；

3）如果type未指定，默认值为JAR；

4）如果指定了一个type但没有指定version，则必须为version留有占位即：mvn:groups/artifact//type

5）Pax URL从0.3.0版本开始支持类别Classifier，如果类别classifier未指定，则不启用类别；

6）如果指定了类别，但没有指定版本version或类型type，则必须未版本和（或）类型留有占位，即：

mvn:groups/artifact///classifier

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mvn:groups/artifact/version//classifier

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mvn:groups/artifact//type/classifier

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版本范围

从0.2.0版本开始，Pax URL Mvn支持版本范围，示例如下

• [1.2.3, 4.5.6) — 1.2.3 <= x < 4.5.6
• [1.2.3, 4.5.6] — 1.2.3 <= x <= 4.5.6
• (1.2.3, 4.5.6) — 1.2.3 < x < 4.5.6
• (1.2.3, 4.5.6] — 1.2.3 < x <= 4.5.6

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  Mvn协议的参数配置

  可以通过两种方式来配置Mvn协议：1）通过OSGi CM；2）通过框架/系统变量。通过CM配置的参数具有高优先级。

  参数名称

  描述

  org.ops4j.pax.url.mvn.certificateCheck

  optional; true/false if the SSL certificate check should be done. Default false.

  org.ops4j.pax.url.mvn.globalUpdatePolicy

  optional; 控制远程maven仓库的更新策略，maven通过本地POM的时间戳比对为依据。可选的策略包括：

  always, daily (default), interval:X (where X is an integer in minutes) or never.

  org.ops4j.pax.url.mvn.localRepository

  optional; 指向本地仓库目录的路径

  org.ops4j.pax.url.mvn.repositories

  optional; 以逗号分隔的仓库URL列表

  org.ops4j.pax.url.mvn.defaultRepositories

  optional; 以逗号分隔的默认仓库URL列表

  org.ops4j.pax.url.mvn.settings

  optional; 指向maven settings.xml的路径

  org.ops4j.pax.url.mvn.proxySupport

  optional; true/false if the proxy support is enabled . Default true.

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  Settings.xml

  如果有必要且maven settings.xml可用，Pax URL Mvn按如下步骤查找settings.xml：

  1. 查找配置参数
  2. 如果未找到，查找 ${user.home}/.m2/settings.xml
  3. 如果未找到，查找 ${maven.home}/conf/settings.xml
  4. 如果未找到，查找 ${M2_HOME}/conf/settings.xml

  Local repository

  Maven本地仓库的查找顺序如下：

  1. 查找配置参数定义；
  2. 如果未找到，在settings.xml中进行查找
  3. 如果未找到，默认认为仓库位于${user.home}/.m2/repository.

  Repositories

  Maven仓库的解析顺序如下:

  1. 在配置参数中查找
  2. 在settings.xml中查找

  如果配置参数中org.ops4j.pax.url.mvn.repositories的值以'+'开始，则来自settings.xml中的仓库地址也将附加到此配置的仓库列表中。

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  设定仓库包含release/snapshot

  可以在参数配置的仓库URL中通过添加如下标识来指定仓库所含有的构件类型（不区分大小写）：

  • 启用snapshots — 添加?@snapshots
  • 禁用releases — 添加?@noreleases

    示例如下:

    http://repository.ops4j.org ; 默认不包含任何标识，只查找releases, 不包括snapshots

    http://repository.ops4j.org/mvn-snapshots@snapshots ; 同时在此仓库查找releases和snapshots

    http://repository.ops4j.org/mvn-snapshots@snapshots@noreleases ; 仅查找snapshots,不查找releases

    默认仓库

    在某些情况下，通过默认仓库配置，可以防止用户配置对下载构件造成影响。如果对org.ops4j.pax.url.mvn.defaultRepositories进行了设置，则Pax URL Mvn首先检查此参数设定的默认仓库列表，如果未找到，则继续查找本地仓库和其它在org.ops4j.pax.url.mvn.repositories中配置的仓库。

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    Karaf中Maven仓库处理策略的配置

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    Karaf通过CM（config admin）服务对Pax URL Mvn协议处理进行参数配置，具体的配置是位于${karaf.home}/etc下的

    org.ops4j.pax.url.mvn.cfg文件：

    ## If set to true, the following property will not allow any certificate to be used# when accessing Maven repositories through SSL##org.ops4j.pax.url.mvn.certificateCheck= ## Path to the local Maven settings file.# The repositories defined in this file will be automatically added to the list# of default repositories if the 'org.ops4j.pax.url.mvn.repositories' property# below is not set.# The following locations are checked for the existence of the settings.xml file#   * 1. looks for the specified url#   * 2. if not found looks for ${user.home}/.m2/settings.xml#   * 3. if not found looks for ${maven.home}/conf/settings.xml#   * 4. if not found looks for ${M2_HOME}/conf/settings.xml##org.ops4j.pax.url.mvn.settings= ## Path to the local Maven repository which is used to avoid downloading# artifacts when they already exist locally.# The value of this property will be extracted from the settings.xml file# above, or defaulted to:#     System.getProperty( "user.home" ) + "/.m2/repository"##org.ops4j.pax.url.mvn.localRepository= ## Default this to false. It's just weird to use undocumented repos#org.ops4j.pax.url.mvn.useFallbackRepositories=false ## Uncomment if you don't wanna use the proxy settings# from the Maven conf/settings.xml file## org.ops4j.pax.url.mvn.proxySupport=false ## Disable aether support by default.  This ensure that the defaultRepositories# below will be used##org.ops4j.pax.url.mvn.disableAether=true ## Comma separated list of repositories scanned when resolving an artifact.# Those repositories will be checked before iterating through the#    below list of repositories and even before the local repository# A repository url can be appended with zero or more of the following flags:#    @snapshots  : the repository contains snaphots#    @noreleases : the repository does not contain any released artifacts## The following property value will add the system folder as a repo.##org.ops4j.pax.url.mvn.defaultRepositories= # Use the default local repo (e.g.~/.m2/repository) as a "remote" repoorg.ops4j.pax.url.mvn.defaultLocalRepoAsRemote=false ## Comma separated list of repositories scanned when resolving an artifact.# The default list includes the following repositories containing releases:#    http://repo1.maven.org/maven2#    http://repository.apache.org/content/groups/snapshots-group#    http://svn.apache.org/repos/asf/servicemix/m2-repo#    http://repository.springsource.com/maven/bundles/release#    http://repository.springsource.com/maven/bundles/external# To add repositories to the default ones, prepend '+' to the list of repositories# to add.# A repository url can be appended with zero or more of the following flags:#    @snapshots  : the repository contains snaphots#    @noreleases : the repository does not contain any released artifacts#    @id=reponid : the id for the repository, just like in the settings.xml this is optional but recomendet## The default list doesn't contain any repository containing snapshots as it can impact the artifacts resolution.# You may want to add the following repositories containing snapshots:#    http://repository.apache.org/content/groups/snapshots-group@id=apache@snapshots@noreleases#    http://oss.sonatype.org/content/repositories/snapshots@id=sonatype.snapshots.deploy@snapshots@norelease#    http://oss.sonatype.org/content/repositories/ops4j-snapshots@id=ops4j.sonatype.snapshots.deploy@snapshots@noreleases#org.ops4j.pax.url.mvn.repositories= \    http://repo1.maven.org/maven2@id=central, \    http://repository.springsource.com/maven/bundles/release@id=spring.ebr, \    file:${karaf.home}/${karaf.default.repository}@id=system.repository, \    file:${karaf.data}/kar@id=kar.repository@multi

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    下面我们来看一下如何通过调整此配置文件，使得Karaf不再依赖远程Maven仓库和本地Maven仓库，让Karaf发布包随意离线部署成为现实。

    首先我们来看一下在org.ops4j.pax.url.mvn.repositories配置中存在两个指向目录路径的仓库URL，即：

    ?file:${karaf.home}/${karaf.default.repository}@id=system.repository, 和 file:${karaf.data}/kar@id=kar.repository@multi。file:${karaf.home}/${karaf.default.repository}@id=system.repository 实际指向的是karaf安装目录下的system目录（也可以根据需要自行调整，karaf.default.repository参数位于etc/system.properties文件中）；file:${karaf.data}/kar@id=kar.repository@multi实际指向的是karaf安装目录下的data/kar目录。

    通过禁用其他仓库URL，只启用这两个位置仓库，则karaf发布程序即可实现离线部署。

    具体配置调整如下：

    # Path to the local Maven settings file.# The repositories defined in this file will be automatically added to the list# of default repositories if the 'org.ops4j.pax.url.mvn.repositories' property# below is not set.# The following locations are checked for the existence of the settings.xml file#   * 1. looks for the specified url#   * 2. if not found looks for ${user.home}/.m2/settings.xml#   * 3. if not found looks for ${maven.home}/conf/settings.xml#   * 4. if not found looks for ${M2_HOME}/conf/settings.xml#org.ops4j.pax.url.mvn.settings= ## Path to the local Maven repository which is used to avoid downloading# artifacts when they already exist locally.# The value of this property will be extracted from the settings.xml file# above, or defaulted to:#     System.getProperty( "user.home" ) + "/.m2/repository"#org.ops4j.pax.url.mvn.localRepository=file:${karaf.home}/${karaf.default.repository}@id=system.repository@snapshots # Use the default local repo (e.g.~/.m2/repository) as a "remote" repoorg.ops4j.pax.url.mvn.defaultLocalRepoAsRemote=true ## Comma separated list of repositories scanned when resolving an artifact.# The default list includes the following repositories:#    http://repo1.maven.org/maven2@id=central#    http://repository.apache.org/content/groups/snapshots-group@id=apache@snapshots@noreleases#    http://repository.springsource.com/maven/bundles/release@id=spring.ebr#    http://oss.sonatype.org/content/repositories/snapshots@id=sonatype.snapshots.deploy@snapshots@norelease#    http://oss.sonatype.org/content/repositories/ops4j-snapshots@id=ops4j.sonatype.snapshots.deploy@snapshots@noreleases#    file:${karaf.home}/${karaf.default.repository}@id=system.repository#    file:${karaf.data}/kar@id=kar.repository@multi# To add repositories to the default ones, prepend '+' to the list of repositories# to add.# A repository url can be appended with zero or more of the following flags:#    @snapshots  : the repository contains snapshots#    @noreleases : the repository does not contain any released artifacts#    @id=repository.id : the id for the repository, just like in the settings.xml this is optional but recommended#org.ops4j.pax.url.mvn.repositories= \    file:${karaf.home}/${karaf.default.repository}@id=system.repository@snapshots, \    file:${karaf.data}/kar@id=kar.repository@multi

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    在此模式下，Pax URL Mvn优先检查system仓库，如果不存在，则检查${user.home}/.m2下的配置，如果没有settings.xml和repository目录，则加载依赖失败。当system库下不存在org.apache.servicemix.specs.activation-api-1.1-1.9.0.jar时，运行日志如下：

    46 -org.ops4j.pax.url.mvn - 1.6.0 | Resolving[mvn:org.apache.servicemix.specs/org.apache.servicemix.specs.activation-api-1.1/1.9.0]

    46 -org.ops4j.pax.url.mvn - 1.6.0 | Using manager SimpleLocalRepositoryManager withpriority 0 for D:\Projects\karaf\assemblies\apache-karaf\target\assembly\system

    46 - org.ops4j.pax.url.mvn - 1.6.0 | Using connectorWagonRepositoryConnector with priority 0 for file:/C:/Users/xxxx/.m2/repository/

    46 -org.ops4j.pax.url.mvn - 1.6.0 | Using connector WagonRepositoryConnector withpriority 0 for file:D:/Projects/karaf/assemblies/apache-karaf/target/assembly/system/

    46 - org.ops4j.pax.url.mvn - 1.6.0 | Error resolvingartifactorg.apache.servicemix.specs:org.apache.servicemix.specs.activation-api-1.1:jar:1.9.0:Couldnot find artifactorg.apache.servicemix.specs:org.apache.servicemix.specs.activation-api-1.1:jar:1.9.0in defaultlocal (file:/C:/Users/xxxx/.m2/repository/)

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    通过此方案，如果发布包中的system目录包含了系统运行所需的所有依赖，则karaf将不再寻求从远程仓库加载依赖，从而实现离线部署。

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    通过上述方案实现karaf离线部署的同时产生了新的问题，如何确保system目录包含所有的依赖同时又不包含无用的冗余依赖？这个问题可以通过karaf-maven-plugin获得解决。下面来看一下配置：

    <plugin>                <groupId>org.apache.karaf.tooling</groupId>                <artifactId>karaf-maven-plugin</artifactId>                <executions>                    <execution>                        <id>install-kar</id>                        <phase>compile</phase>                        <goals>                            <goal>install-kars</goal>                        </goals>                    </execution>                    <execution>                        <id>features-add-to-repo</id>                        <phase>generate-resources</phase>                        <goals>                            <goal>features-add-to-repository</goal>                        </goals>                        <configuration>                            <descriptors>                                <descriptor>mvn:org.apache.karaf.features/standard/${karaf.version}/xml/features</descriptor>                                <descriptor>mvn:org.apache.karaf.features/spring/${karaf.version}/xml/features</descriptor>                                ……                                                      </descriptors>                            <features>                                <feature>http</feature>                                   <feature>spring</feature>                                …                            </features>                            <repository>target/assembly/system</repository>                        </configuration>                    </execution>                    <execution>                        <id>package</id>                        <goals>                            <goal>instance-create-archive</goal>                        </goals>                    </execution>                </executions>                           </plugin>

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    通过此配置，系统在打包时，自动将karaf的standard feature库中的http feature及其依赖和spring feature库中的spring feature及其依赖下载到system目录中一起打包发布。

    结论

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    通过上述方案，我们即可实现基于Karaf的项目自动打包、测试及发布。