URI Resolver

From Gcube Wiki
Revision as of 11:28, 20 October 2014 by Francesco.mangiacrapa (Talk | contribs) (Uri Resolver Manager)

Jump to: navigation, search

The URI Resolver is an HTTP URI resolver implemented as an HTTP servlet which gives access trough HTTP to different protocols URIs.

SMP Resolver

The first version of the component is able to give HTTP resolution to SMP protocol URIs [1].

Once deployed in a servlet container as Tomcat, the servlet can be used to resolve SMP URIs as follows:

URL url = new URL("http://<hostname>:<port>/uri-resolver/smp?smp-uri=smp://.....);


The HTTP URI can be also used to retrieve files using wget or trough a Web Browser.. just click on the link :

http://dev.d4science.org/uri-resolver/smp?smp-uri=smp://Wikipedia_logo_silver.png?5ezvFfBOLqaqBlwCEtAvz4ch5BUu1ag3yftpCvV+gayz9bAtSsnO1/sX6pemTKbDe0qbchLexXeWgGcJlskYE8td9QSDXSZj5VSl9kdN9SN0/LRYaWUZuP4Q1J7lEiwkU4GKPsiD6PDRVcT4QAqTEy5hSIbr6o4Y&fileName=wikipediaLogo&contentType=image/jpeg

Apart from the smp-uri mandatory parameter, two optional paramters can be used:

  • fileName : to specify the output file name ( default: fromStorageManager)
  • contentType : to specify the output file content-type ( default: unknown/unknown)

The artifact is available on Nexus with the following coordinates:

  <groupId>org.gcube.data.transfer</groupId>
  <artifactId>uri-resolver</artifactId>
  <version>1.1.0-SNAPSHOT</version>
  <type>war</type>

Runtime Resource

The address and the configuration information of the servlet are registered on the gCube Information System as Runtime Resource. This in an example of the Runtime Resource to configure:

<Profile>
        
      <Category>Service</Category>
        
      <Name>HTTP-URI-Resolver</Name>
        
      <Description>HTTP URI Resolver</Description>
        
      <Platform>
            
         <Name>tomcat</Name>
            
         <Version>6</Version>
            
         <MinorVersion>0</MinorVersion>
            
         <RevisionVersion>0</RevisionVersion>
            
         <BuildVersion>0</BuildVersion>
        
      </Platform>
        
      <RunTime>
            
         <HostedOn>dev.d4science.org</HostedOn>
            
         <GHN UniqueID="" />
            
         <Status>READY</Status>
        
      </RunTime>
        
      <AccessPoint>
            
         <Description>SMP URI Resolver</Description>
            
         <Interface>
                
            <Endpoint EntryName="smp">http://dev.d4science.org/uri-resolver/smp</Endpoint>
            
         </Interface>
            
         <AccessData>
                
            <Username />
                
            <Password>6vW1u92cpdgHzYAgIurn9w==</Password>
            
         </AccessData>
            
         <Properties>
                
            <Property>
                    
               <Name>SMP_URI_parameter</Name>
                    
               <Value encrypted="false">smp-uri</Value>
                
            </Property>

               <Property>
                    
               <Name>fileName_parameter</Name>
                    
               <Value encrypted="false">fileName</Value>
                
            </Property>

            <Property>
                    
               <Name>contentType_parameter</Name>
                    
               <Value encrypted="false">contentType</Value>
                
            </Property> 
            
         </Properties>
        
      </AccessPoint>
    
   </Profile>

Query

The following code snippet can be used to retrieve from the gCube Information System the info to configure the resolver

 
        ScopeProvider.instance.set(<scope>);
 
	XQuery query = queryFor(ServiceEndpoint.class);
 
	query.addCondition("$resource/Profile/Name/text() eq 'HTTP-URI-Resolver'").setResult("$resource/Profile/AccessPoint");
 
	DiscoveryClient<AccessPoint> client = clientFor(AccessPoint.class);
 
	List<AccessPoint> endpoints = client.submit(query);
 
	if (endpoints.size() == 0)
		throw new Exception("No Resolver available");
 
	//Base Address
        System.out.println(endpoints.get(0).address());
        //Query URL parameter
	System.out.println(endpoints.get(0).propertyMap().get("SMP_URI_parameter").value());


GIS Resolver

The first version of the component is able to give HTTP resolution (as redirect to Gis Viewer Application) to display and navigate on map the gis layers stored in iMarine Geonetowrk #iMarine_GeoNetwork

The Gis Resolver can be used to resolve Gis Layer using a Web Browser link as follows:

http://dev.d4science.org/uri-resolver/gis?gis-UUID=<UUID>&scope=<SCOPE>

The link must include two mandatory parameters:

  • gis-UUID : to specify the Metadata Universally Unique Identifier (UUID - used in iMarine Geonetwork). The UUID identifies the gis layer which you want to show in Gis Viewer Application
  • scope : to specify the "scope" for discovering the iMarine Geonetowrk service (e.g. scope=/gcube/devsec/devVRE)

The artifact is available on Nexus with the following coordinates:

  <groupId>org.gcube.data.transfer</groupId>
  <artifactId>uri-resolver</artifactId>
  <version>1.2.0-SNAPSHOT</version>
  <type>war</type>


Uri Resolver Manager

The Uri Resolver Manager is a library to get a public link of a resource reachable from a (Gcube) Http Resolver

At moment, the resource types are GIS or SMP reachable from Uri-Resolver and Gis-Resolver.

The Uri Resolver Manager look up the (Generic Resource) "Uri-Resolver-Map" to read the mapping: Application Type -> (Runtime Resource of its) Resolver, e.g. GIS -> Gis-Resolver, SMP -> HTTP-URI-Resolver

The mandatory parameters to forward correctly the HTTP request at the Resolver are dynamically read from Runtime Resource

The artifact is available on Nexus with the following coordinates:

   <groupId>org.gcube.portlets.user</groupId>
   <artifactId>uri-resolver-manager</artifactId>
   <version>1.0.0-SNAPSHOT</version>

A simple java How-to:

public static void main(String[] args) {
 
		try {
                        ScopeProvider.instance.set("/gcube/devsec/devVRE");
			UriResolverManager resolver = new UriResolverManager("GIS");
			Map<String, String> params = new HashMap<String, String>();
			params.put("gis-UUID", "eb1a1b63-f324-47ee-9522-b8f5803e19ec");
			params.put("scope", "/gcube/devsec/devVRE");
			String shortLink = resolver.getLink(params, true); //true, link is shorted otherwise none
			System.out.println(shortLink);
		} catch (UriResolverMapException e) {
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		}catch (Exception e) {
			e.printStackTrace();
		}
	}