什么是maven存储库协议？

Question

I have been learning a lot about Maven lately and am very impressed. Where can I find information about communicating with, deploying to and retrieving from a repository in the same manner as Maven does? Is this done through some published protocol?

I have found information about OSGI (and OBR) but cannot tell if this is what I should be looking into.

I would like to do this in .net (for whatever reason). I do not mind looking through java source code if someone could point me to the correct component, but would much rather be pointed to the protocol specifications.

[EDIT] I see a lot of answers regarding HTTP. I would like to further clarify, I am not looking for the transfer protocol, I am looking for the API protocol. For example, the Simple Object Access Protocol (SOAP) uses the Hyper Text Transfer Protocol to transfer messages. What is the access protocol for Maven?

Answer 1

As khmarbaise already said the transfer protocol is in most cases http(s), but there are other protocols available, eg simple file access for local repositories, WebDAV, SCP, SFTP, and so on. A maven repository is more a special directory layout. There are servers like Nexus or Artifactory that offer additional functionality like proxying remote repositories or certain checks like authentication.

https://maven.apache.org/guides/introduction/introduction-to-repositories.html

Taken from http://wiki.jfrog.org/confluence/display/rtf/repository+layouts Maven Repository Layout: [orgPath]/[module]/[baseRev](-[folderItegRev])/[module]-[baseRev](-[fileItegRev])(-[classifier]).[ext]

Example org/eclipse/jetty/jetty-ajp/7.0.2.v20100331/jetty-ajp-7.0.2.v20100331.jar

Answer 2

The usual protocol is http furthermore for .net there exists already a solution which is called nuget which supports that already and works with some of the repository managers like neuxs and artifactory.

Ah...Maven uses it's own protocol. No SOAP etc. May be a look here will help a little bit. And furthermore this .

Update You can simply download an artifact from a Maven repository by wget ...which is simply a http-get operation. To uplodate an artifact is simply a http-put ...you can do this by curl.

Answer 3

Strictly, there is no special access protocol for Maven. Maven uses plain HTTP to get artifacts from repository. Repository should have special layout, ie URL structure (which simply projected to usual directory structure). You can organize your own repo simply by organizing directories in a special way: [orgPath]/[module]/[baseRev](-[folderItegRev])/[module]-[baseRev](-[fileItegRev])(-[classifier]).[ext] without any special software on server side.

So, it is more about directory structure than special protocol. Very simple and working approach.

Of course, if you wanna additional services around it (like search, access control, stats etc) you should do it yourself. That's what JFrog does with its Artifactory product.

Answer 4

As far as I know, there isn't really a protocol. A Maven repository is just a specific resource structure available over HTTP (or in a local directory.) There's a somewhat dated description available at Codehaus .

"Deploying to" a repository means uploading the file in whichever way you wish as long as it's available to get from the above layout later. The documentation for the deploy plugin provides examples for FTP and SSH, which implies a simple file upload into such a directory structure. But you might as well upload files to a custom web service that stores them in a database that is then appropriately exposed over HTTP. Maven won't really care; artefact deployment, storage, and repository access are decoupled.

Answer 5

HTTP GET, with this format:

GET /content/repositories/approved-from-central/commons-logging/commons-logging-api/1.1/commons-logging-api-1.1.pom HTTP/1.1
Cache-control: no-cache
Cache-store: no-store
Pragma: no-cache
Expires: 0
Accept-Encoding: gzip
User-Agent: Apache-Maven/3.3.9 (Java 1.8.0_102; Windows 7 6.1)
Host: localhost
Connection: Keep-Alive

I have documented it here http://www.javamonamour.org/2017/10/maven-to-repository-protocol.html