Difference between revisions of "URI Resolver"

Revision as of 18:48, 11 July 2013

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());