Validate the GAECV before processing

[jvanzyl]

Probably need to perform some basic validation to make sure the input conforms to:

<groupId>:<artifactId>[:<extension>[:<classifier>]]:<version>

 jvanzyl$ gavsearch com.fasterxml.jackson.core:jackson-core
Searching for `com.fasterxml.jackson.core:jackson-core` on search.maven.org...
javax.ws.rs.ProcessingException: RESTEASY003145: Unable to find a MessageBodyReader of content-type text/plain and type class gavsearch$MvnSearchResult
	at org.jboss.resteasy.core.interception.jaxrs.ClientReaderInterceptorContext.throwReaderNotFound(ClientReaderInterceptorContext.java:47)
	at org.jboss.resteasy.core.interception.jaxrs.AbstractReaderInterceptorContext.getReader(AbstractReaderInterceptorContext.java:133)
	at org.jboss.resteasy.core.interception.jaxrs.AbstractReaderInterceptorContext.proceed(AbstractReaderInterceptorContext.java:75)
	at org.jboss.resteasy.client.jaxrs.internal.ClientResponse.readFrom(ClientResponse.java:214)
	at org.jboss.resteasy.specimpl.BuiltResponse.readEntity(BuiltResponse.java:88)
	at org.jboss.resteasy.specimpl.AbstractBuiltResponse.readEntity(AbstractBuiltResponse.java:262)
	at gavsearch.call(gavsearch.java:81)
	at gavsearch.call(gavsearch.java:44)
	at picocli.CommandLine.executeUserObject(CommandLine.java:1783)
	at picocli.CommandLine.access$900(CommandLine.java:145)
	at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(CommandLine.java:2150)
	at picocli.CommandLine$RunLast.handle(CommandLine.java:2144)
	at picocli.CommandLine$RunLast.handle(CommandLine.java:2108)
	at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:1975)
	at picocli.CommandLine.execute(CommandLine.java:1904)
	at gavsearch.main(gavsearch.java:63)

[quintesse]

It's an issue with how we call the API. On their website something like com.fasterxml.jackson.core:jackson-core gets translated to: g:com.fasterxml.jackson.core AND a:jackson-core. The parsing of that is done in their web page, so the API only takes that more complex query syntax. We'll have to fix that.

[jvanzyl]

I just chatted with @maxandersen, I'm happy to submit a PR.

[quintesse]

Btw these are their docs:

By coordinates

Group:

• g:junit

Artifact:

• a:junit

Version:

• v:4.11

Packaging:

• p:jar
• p:war

Classifier:

• l:sources
• l:javadocs

You can also search in combinations, using the "and" keyword: g:junit and v:4.11

By classes
Class name

• c:JUnit4
  Full class name
• fc:org.sonatype.nexus
  By checksums
  SHA-1
• 1:2973d150c0dc1fefe998f834810d68f278ea58ec