最近使用karaf+Jetty使用feature碰到了很多問題

http://www.itpub.net/thread-1776847-1-1.html JPA資料

http://springsfeng.iteye.com/blog/1392658 feature參考

http://blog.csdn.net/caolaosanahnu/article/details/7933333

粗心導致排錯搞了兩天，太悲催了，Caused by: java.lang.ClassNotFoundException: org.eclipse.jetty.npn.NextProtoNego$ServerProvider的異常出現，是由於在karaf中npn-boot的版本設置錯誤了。。。。。。

set JAVA_OPTS=%JAVA_OPTS% -Djetty.home=%KARAF_BASE%/jetty -Xbootclasspath/p:npn-boot-${npn.boot.version}.jar

基於Karaf的項目離線打包與發佈

Karaf對OSGi Bundle的組織採用Pax的maven url方式，這也隱性的繼承了maven的特性，即，所有的依賴來自maven倉庫，在實際開發中，這大大的便利了項目結構的組織和維護，開發人員只要指明對某個bundle的maven依賴，karaf自動去選取和下載。但是，在基於karaf的項目部署時，項目或產品的發佈環境往往要求嚴格，不能夠隨意訪問遠程的maven倉庫；那提供一個本地maven倉庫？顯然這也不合理，本地maven倉庫的維護加重了維護的複雜性。本文主要就離線發佈karaf的需求實現進行探討。

Pax URL Mvn協議

在討論karaf的maven依賴加載與管理之前，我們先了解一下Pax URL項目的Mvn協議：

 

mvn-uri := 'mvn:' [ repository-url '!' ] group-id '/' artifact-id [ '/' [version] [ '/' [type] [ '/' classifier ] ] ] ]
repository-url := < rfc2396 uri > ; an url that points to a maven 2 repository
group-id := < maven groupId > ; group id of maven artifact
artifact-id := < maven artifactId > ; artifact id of maven artifact
version := < maven version > | 'LATEST' | range ; version of maven artifact
range := ( '[' | '(' ) version ',' version ( ')' | ']' )
type := < maven type> ; type of maven artifact
classifier := < maven classifier> ; maven artifact classifier

假設項目需要依賴Pax Web的service-0.2.0-SNAPSHOT.jar,對應的Mvn協議示例如下：

 

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 - 從目錄中加載

mvn:org.ops4j.pax.web/pax-web-features/3.0.4-SNAPSHOT/xml/features --標識pax-web-features-3.0.4-SNAPSHOT-features.xml構件

協議要點

1）如果版本（version）未指定，將使用默認值“LATEST”，並從可用的Maven元數據（metadata）中解析最新的版本，maven metadata的示例如下：

 

<?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>

 

 

2）如果version是SNAPSHOT版本，則採用與maven一致的策略來解析SNAPSHOT版本；

3）如果type未指定，默認值爲JAR；

4）如果指定了一個type但沒有指定version，則必須爲version留有佔位即：mvn:groups/artifact//type

5）Pax URL從0.3.0版本開始支持類別Classifier，如果類別classifier未指定，則不啓用類別；

6）如果指定了類別，但沒有指定版本version或類型type，則必須未版本和（或）類型留有佔位，即：

mvn:groups/artifact///classifier

 或 

mvn:groups/artifact/version//classifier

 或 

mvn:groups/artifact//type/classifier

 

版本範圍

從0.2.0版本開始，Pax URL Mvn支持版本範圍，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

 

Mvn協議的參數配置

可以通過兩種方式來配置Mvn協議：1）通過OSGi CM；2）通過框架/系統變量。通過CM配置的參數具有高優先級。

參數名稱	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; 控制遠程maven倉庫的更新策略，maven通過本地POM的時間戳比對爲依據。可選的策略包括： always, daily (default), interval:X (where X is an integer in minutes) or never.
org.ops4j.pax.url.mvn.localRepository	optional; 指向本地倉庫目錄的路徑
org.ops4j.pax.url.mvn.repositories	optional; 以逗號分隔的倉庫URL列表
org.ops4j.pax.url.mvn.defaultRepositories	optional; 以逗號分隔的默認倉庫URL列表
org.ops4j.pax.url.mvn.settings	optional; 指向maven settings.xml的路徑
org.ops4j.pax.url.mvn.proxySupport	optional; true/false if the proxy support is enabled . Default true.

 

Settings.xml

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

1. 查找配置參數
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本地倉庫的查找順序如下：

1. 查找配置參數定義；
2. 如果未找到，在settings.xml中進行查找
3. 如果未找到，默認認爲倉庫位於${user.home}/.m2/repository.

Repositories

Maven倉庫的解析順序如下:

1. 在配置參數中查找
2. 在settings.xml中查找

如果配置參數中org.ops4j.pax.url.mvn.repositories的值以'+'開始，則來自settings.xml中的倉庫地址也將附加到此配置的倉庫列表中。

 

設定倉庫包含release/snapshot

可以在參數配置的倉庫URL中通過添加如下標識來指定倉庫所含有的構件類型（不區分大小寫）：

• 啓用snapshots — 添加 @snapshots
• 禁用releases — 添加 @noreleases

示例如下:

http://repository.ops4j.org ; 默認不包含任何標識，只查找releases, 不包括snapshots

http://repository.ops4j.org/mvn-snapshots@snapshots ; 同時在此倉庫查找releases和snapshots

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

默認倉庫

在某些情況下，通過默認倉庫配置，可以防止用戶配置對下載構件造成影響。如果對org.ops4j.pax.url.mvn.defaultRepositories進行了設置，則Pax URL Mvn首先檢查此參數設定的默認倉庫列表，如果未找到，則繼續查找本地倉庫和其它在org.ops4j.pax.url.mvn.repositories中配置的倉庫。

 

Karaf中Maven倉庫處理策略的配置

 

Karaf通過CM（config admin）服務對Pax URL Mvn協議處理進行參數配置，具體的配置是位於${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" repo
org.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

 

下面我們來看一下如何通過調整此配置文件，使得Karaf不再依賴遠程Maven倉庫和本地Maven倉庫，讓Karaf發佈包隨意離線部署成爲現實。

首先我們來看一下在org.ops4j.pax.url.mvn.repositories配置中存在兩個指向目錄路徑的倉庫URL，即：

 file:${karaf.home}/${karaf.default.repository}@id=system.repository, 和 file:${karaf.data}/kar@id=kar.repository@multi。file:${karaf.home}/${karaf.default.repository}@id=system.repository 實際指向的是karaf安裝目錄下的system目錄（也可以根據需要自行調整，karaf.default.repository參數位於etc/system.properties文件中）；file:${karaf.data}/kar@id=kar.repository@multi實際指向的是karaf安裝目錄下的data/kar目錄。

通過禁用其他倉庫URL，只啓用這兩個位置倉庫，則karaf發佈程序即可實現離線部署。

具體配置調整如下：

# 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
#
<span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px; list-style: none outside none; word-break: normal; word-wrap: break-word; color: rgb(255, 102, 0);">org.ops4j.pax.url.mvn.settings=</span></span>

#
# 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"
#
<span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px; list-style: none outside none; word-break: normal; word-wrap: break-word; color: rgb(255, 102, 0);">org.ops4j.pax.url.mvn.localRepository=file:${karaf.home}/${karaf.default.repository}@id=system.repository@snapshots</span></span>

# Use the default local repo (e.g.~/.m2/repository) as a "remote" repo
<span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px; list-style: none outside none; word-break: normal; word-wrap: break-word; color: rgb(255, 102, 0);">org.ops4j.pax.url.mvn.defaultLocalRepoAsRemote=true</span></span>

#
# 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:${karaf.data}/kar@id=kar.repository@multi
# To add repositories to the default ones, prepend '+' to the list of repositories
# to add.
# A repository url can be appended with zero or more of the following flags:
#    @snapshots  : the repository contains snapshots
#    @noreleases : the repository does not contain any released artifacts
#    @id=repository.id : the id for the repository, just like in the settings.xml this is optional but recommended
#
<span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px; list-style: none outside none; word-break: normal; word-wrap: break-word; color: rgb(255, 102, 0);">org.ops4j.pax.url.mvn.repositories= \
    file:${karaf.home}/${karaf.default.repository}@id=system.repository@snapshots, \
    file:${karaf.data}/kar@id=kar.repository@multi</span></span>

 

 

在此模式下，Pax URL Mvn優先檢查system倉庫，如果不存在，則檢查${user.home}/.m2下的配置，如果沒有settings.xml和repository目錄，則加載依賴失敗。當system庫下不存在org.apache.servicemix.specs.activation-api-1.1-1.9.0.jar時，運行日誌如下：

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 with
priority 0 for D:\Projects\karaf\assemblies\apache-karaf\target\assembly\system

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

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

46 - org.ops4j.pax.url.mvn - 1.6.0 | Error resolving
artifactorg.apache.servicemix.specs:org.apache.servicemix.specs.activation-api-1.1:jar:1.9.0:Could
not find artifact
org.apache.servicemix.specs:org.apache.servicemix.specs.activation-api-1.1:jar:1.9.0
in defaultlocal (file:/C:/Users/xxxx/.m2/repository/)

 

通過此方案，如果發佈包中的system目錄包含了系統運行所需的所有依賴，則karaf將不再尋求從遠程倉庫加載依賴，從而實現離線部署。

 

通過上述方案實現karaf離線部署的同時產生了新的問題，如何確保system目錄包含所有的依賴同時又不包含無用的冗餘依賴？這個問題可以通過karaf-maven-plugin獲得解決。下面來看一下配置：

<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>
                            <span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px; list-style: none outside none; word-break: normal; word-wrap: break-word; color: rgb(255, 102, 0);"><goal>features-add-to-repository</goal></span></span>
                        </goals>
                        <configuration>
                            <descriptors>
                                <<span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px; list-style: none outside none; word-break: normal; word-wrap: break-word; color: rgb(0, 0, 255);">descriptor>mvn:org.apache.karaf.features/standard/${karaf.version}/xml/features</descriptor>
                                <descriptor>mvn:org.apache.karaf.features/spring/${karaf.version}/xml/features</descriptor></span></span>
                                ……
                            </descriptors>
                            <features>
                                <span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px; list-style: none outside none; word-break: normal; word-wrap: break-word; color: rgb(0, 0, 255);"><feature>http</feature>
                                <feature>spring</feature></span></span>
                                …
                            </features>
                            <span style="margin: 0px; padding: 0px;"><span style="margin: 0px; padding: 0px; list-style: none outside none; word-break: normal; word-wrap: break-word; color: rgb(128, 0, 128);"><repository>target/assembly/system</repository></span></span>
                        </configuration>
                    </execution>
                    <execution>
                        <id>package</id>
                        <goals>
                            <goal>instance-create-archive</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

 

通過此配置，系統在打包時，自動將karaf的standard feature庫中的http feature及其依賴和spring feature庫中的spring feature及其依賴下載到system目錄中一起打包發佈。

結論

 

通過上述方案，我們即可實現基於Karaf的項目自動打包、測試及發佈。