VIVO-1614 - Update to allow the TPF API to be toggled via the runtime.properties. (#127)

* Update to allow the TPF API to be toggled via the runtime.properties.

Resolves: https://jira.duraspace.org/browse/VIVO-1614

api/src/main/java/org/vivoweb/linkeddatafragments/servlet/VitroLinkedDataFragmentServlet.java

@@ -6,8 +6,10 @@ import edu.cornell.mannlib.vitro.webapp.controller.VitroHttpServlet;
 import edu.cornell.mannlib.vitro.webapp.dao.OntologyDao;
 import edu.cornell.mannlib.vitro.webapp.modelaccess.ModelAccess;
 import edu.cornell.mannlib.vitro.webapp.rdfservice.RDFService;
+import edu.cornell.mannlib.vitro.webapp.config.ConfigurationProperties;
 import org.apache.commons.io.IOUtils;
 import org.apache.jena.riot.Lang;
+import org.apache.commons.lang3.StringUtils;
 import org.linkeddatafragments.config.ConfigReader;
 import org.linkeddatafragments.datasource.DataSourceFactory;
 import org.linkeddatafragments.datasource.DataSourceTypesRegistry;
@@ -47,11 +49,15 @@ import java.util.Map.Entry;
 @WebServlet(name = "TpfServlet", urlPatterns = {"/tpf/*"})
 public class VitroLinkedDataFragmentServlet extends VitroHttpServlet {
 
-    private final static long serialVersionUID = 1L;
+	private final static long serialVersionUID = 1L;
+	
+	private static final String PROPERTY_TPF_ACTIVE_FLAG = "tpf.activeFlag";
 	
     private ConfigReader config;
     private final HashMap<String, IDataSource> dataSources = new HashMap<>();
     private final Collection<String> mimeTypes = new ArrayList<>();
+    private ConfigurationProperties configProps;
+    private String tpfActiveFlag;
 
     private File getConfigFile(ServletConfig config) throws IOException {
         String path = config.getServletContext().getRealPath("/");
@@ -73,6 +79,16 @@ public class VitroLinkedDataFragmentServlet extends VitroHttpServlet {
     public void init(ServletConfig servletConfig) throws ServletException {
         try {
             ServletContext ctx = servletConfig.getServletContext();
+            configProps = ConfigurationProperties.getBean(ctx);
+            
+            if (!configurationPresent()) {
+            	throw new ServletException("TPF is currently disabled. To enable, add 'tpfActive.flag=true' to the runtime.properties.");
+            } else {
+            	if (!tpfActiveFlag.equalsIgnoreCase("true")) {
+            		throw new ServletException("TPF is currently disabled. To enable, set 'tpfActive.flag=true' in runtime.properties.");
+            	}
+            }
+            
             RDFService rdfService = ModelAccess.on(ctx).getRDFService();
             RDFServiceBasedRequestProcessorForTPFs.setRDFService(rdfService);
 
@@ -120,6 +136,16 @@ public class VitroLinkedDataFragmentServlet extends VitroHttpServlet {
         }
     }
 
+    private boolean configurationPresent() {
+    	String activeFlag = configProps.getProperty(PROPERTY_TPF_ACTIVE_FLAG);
+    	if (StringUtils.isNotEmpty(activeFlag)) {
+    		this.tpfActiveFlag = activeFlag;
+    		return true;
+    	} else {
+    		return false;
+    	}
+    }
+    
     private IDataSource getDataSource(HttpServletRequest request) throws DataSourceNotFoundException {
         String contextPath = request.getContextPath();
         String requestURI = request.getRequestURI();

checkstyle/src/main/resources/vitro-checkstyle/checkstyle-suppressions.xml

@@ -3,6 +3,9 @@
     "-//Puppy Crawl//DTD Suppressions 1.1//EN"
     "http://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
 <suppressions>
+  <!-- For Debug Only -->
+  <!-- <suppress files=".+\.(?:txt|xml|csv|sh|thrift|html|sql|eot|ttf|woff|css|png|java|jar|zip|war|class|tar|bin|gif|jpg|jpeg|properties)$" checks=".*"/> -->	
+
   <!-- Suppressions for Javadoc in Test classes -->
   <suppress checks="JavadocMethod" files="src[/\\]test[/\\]java"/>
   <suppress checks="JavadocType" files="src[/\\]test[/\\]java"/>

home/src/main/resources/config/example.runtime.properties

@@ -153,3 +153,8 @@ proxy.eligibleTypeList = http://www.w3.org/2002/07/owl#Thing
 # This should not be used with languages.forceLocale, which will override it.
 #
 # languages.selectableLocales = en, es, fr
+
+# Triple pattern fragments is a very fast, very simple means for querying a triple store.
+# The triple pattern fragments API in VIVO puts little load on the server, providing a simple means for getting data from the triple store. The API has a web interface for manual use, can be used from the command line via curl, and can be used by programs.
+
+# tpf.activeFlag = true