为什么Maven每次都会先从Maven中央服务器搜索我的私有依赖项jar？

Question

I have a jar named brandstore-repository in my maven private servers (nexus),

why maven first search it from maven center server every time?

[artifact:mvn] Downloading: http://search.maven.org/remotecontent?filepath=/com/jumbo/brandstore/brandstore-repository/4.0.0/brandstore-repository-4.0.0.pom
[artifact:mvn] Downloading: http://repository.jboss.com/maven2/com/jumbo/brandstore/brandstore-repository/4.0.0/brandstore-repository-4.0.0.pom
[artifact:mvn] Downloading: https://oss.sonatype.org/content/repositories/snapshots//com/jumbo/brandstore/brandstore-repository/4.0.0/brandstore-repository-4.0.0.pom
[artifact:mvn] Downloading: http://10.8.12.100/nexus/content/groups/public/com/jumbo/brandstore/brandstore-repository/4.0.0/brandstore-repository-4.0.0.pom
[artifact:mvn] 1K downloaded
[artifact:mvn] Downloading: http://search.maven.org/remotecontent?filepath=/com/jumbo/brandstore/brandstore/4.0.0/brandstore-4.0.0.pom
[artifact:mvn] Downloading: http://repository.jboss.com/maven2/com/jumbo/brandstore/brandstore/4.0.0/brandstore-4.0.0.pom
[artifact:mvn] Downloading: https://oss.sonatype.org/content/repositories/snapshots//com/jumbo/brandstore/brandstore/4.0.0/brandstore-4.0.0.pom
[artifact:mvn] Downloading: http://10.8.12.100/nexus/content/groups/public/com/jumbo/brandstore/brandstore/4.0.0/brandstore-4.0.0.pom
[artifact:mvn] 17K downloaded
[artifact:mvn] Downloading: http://search.maven.org/remotecontent?filepath=/com/jumbo/brandstore/brandstore-repository/4.0.0/brandstore-repository-4.0.0.jar
[artifact:mvn] Downloading: http://repository.jboss.com/maven2/com/jumbo/brandstore/brandstore-repository/4.0.0/brandstore-repository-4.0.0.jar
[artifact:mvn] Downloading: https://oss.sonatype.org/content/repositories/snapshots//com/jumbo/brandstore/brandstore-repository/4.0.0/brandstore-repository-4.0.0.jar
[artifact:mvn] Downloading: http://10.8.12.100/nexus/content/groups/public/com/jumbo/brandstore/brandstore-repository/4.0.0/brandstore-repository-4.0.0.jar
[artifact:mvn] 913K downloaded

In my setting.xml file, I have already set my private servers (nexus) "http://10.8.12.100/nexus/content/groups/public" on top

and activeProfiles i set "profile-baozun" before "maven-home"

<profiles>
        <profile>
            <id>profile-baozun</id>
            <repositories>
                <repository>
                    <id>public</id>
                    <url>http://10.8.12.100/nexus/content/groups/public</url>
                    <releases>
                        <enabled>true</enabled>
                    </releases>
                    <snapshots>
                        <enabled>true</enabled>
                    </snapshots>
                </repository>

                <repository>
                    <id>loxia2</id>
                    <url>http://loxia2.googlecode.com/svn/repository</url>
                    <releases>
                        <enabled>true</enabled>
                        <checksumPolicy>warn</checksumPolicy>
                    </releases>
                </repository>
            </repositories>
        </profile> 

        <profile>
            <id>maven-home</id>
            <repositories>
                <repository>
                    <id>central</id>
                    <url>http://search.maven.org/remotecontent?filepath=</url>
                </repository>

                <repository>
                    <id>jboss</id>
                    <url>http://repository.jboss.com/maven2</url>
                </repository>

                <repository>
                    <id>sonatype</id>
                    <url>https://oss.sonatype.org/content/repositories/snapshots/</url>
                </repository>
            </repositories>
        </profile>
    </profiles>

    <activeProfiles>
        <activeProfile>maven-home</activeProfile>
                 <activeProfile>profile-baozun</activeProfile>

    </activeProfiles>

Answer 1

Maven has no way of knowing where your maven coordinates point to without checking the repository indexes. I would suggest that you have your nexus proxy the central maven repository and others, and then add a mirror stanza in settings.xml.

This way all requests will go to nexus, and if nexus doesn't have the artifact, it will cache it and serve it, so that next time, you will get it even faster.

Answer 2

I would suggest to set up the settings.xml to only point to a repository group and then adding other proxy and hosted repositories to the group in Nexus. That way you do not have to reconfigure the settings.xml anymore after you did the first install.

Check out a sample settings.xml in the Nexus book .