Moving Data Distribution API into the Vitro codebase

api/pom.xml

@@ -21,9 +21,31 @@
 
     <build>
         <plugins>
+            <plugin>
+                <artifactId>maven-enforcer-plugin</artifactId>
+                <version>3.5.0</version>
+                <executions>
+                    <execution>
+                        <id>enforce-java</id>
+                        <phase>validate</phase>
+                        <goals>
+                            <goal>enforce</goal>
+                        </goals>
+                        <configuration>
+                            <rules>
+                               <requireJavaVersion>
+                                    <version>11</version>
+                                    <message>You are running an incompatible version of Java. Minimum required version is 11.</message>
+                                </requireJavaVersion>
+                            </rules>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.12.4</version>
                 <configuration>
                     <runOrder>alphabetical</runOrder>
                 </configuration>
@@ -91,6 +113,11 @@
             <version>1.15.1-SNAPSHOT</version>
             <type>pom</type>
         </dependency>
+        <dependency>
+            <groupId>org.reflections</groupId>
+            <artifactId>reflections</artifactId>
+            <version>0.10.2</version>
+        </dependency>
         <dependency>
             <groupId>javax.servlet</groupId>
             <artifactId>javax.servlet-api</artifactId>
@@ -104,6 +131,12 @@
             <scope>provided</scope>
         </dependency>
 
+	<dependency>
+	    <groupId>org.mockito</groupId>
+	    <artifactId>mockito-core</artifactId>
+	    <version>5.15.2</version>
+	    <scope>test</scope>
+    	</dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>

api/src/main/java/edu/cornell/library/scholars/webapp/controller/api/DistributeDataApiController.java

@@ -0,0 +1,165 @@
+///* $This file is distributed under the terms of the license in /doc/license.txt$ */
+
+package edu.cornell.library.scholars.webapp.controller.api;
+
+import static edu.cornell.mannlib.vitro.webapp.modelaccess.ModelNames.DISPLAY;
+import static edu.cornell.mannlib.vitro.webapp.utils.sparqlrunner.SparqlQueryRunner.createSelectQueryContext;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.io.PrintWriter;
+import java.util.Collections;
+import java.util.List;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import edu.cornell.library.scholars.webapp.controller.api.distribute.DataDistributor;
+import edu.cornell.library.scholars.webapp.controller.api.distribute.DataDistributor.ActionFailedException;
+import edu.cornell.library.scholars.webapp.controller.api.distribute.DataDistributor.DataDistributorException;
+import edu.cornell.library.scholars.webapp.controller.api.distribute.DataDistributor.MissingParametersException;
+import edu.cornell.library.scholars.webapp.controller.api.distribute.DataDistributor.NoSuchActionException;
+import edu.cornell.library.scholars.webapp.controller.api.distribute.DataDistributor.NotAuthorizedException;
+import edu.cornell.library.scholars.webapp.controller.api.distribute.DataDistributorContextImpl;
+import edu.cornell.mannlib.vitro.webapp.controller.api.VitroApiServlet;
+import edu.cornell.mannlib.vitro.webapp.modelaccess.ModelAccess;
+import edu.cornell.mannlib.vitro.webapp.utils.configuration.ConfigurationBeanLoader;
+import edu.cornell.mannlib.vitro.webapp.utils.configuration.ConfigurationBeanLoaderException;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.jena.rdf.model.Model;
+
+/**
+ * Find a distributor description for the requested action. Create an instance
+ * of that distributor. Write its data to the HTTP response.
+ */
+@WebServlet(name = "DistributeDataApi", urlPatterns = { "/api/dataRequest/*" })
+public class DistributeDataApiController extends VitroApiServlet {
+    private static final Log log = LogFactory.getLog(DistributeDataApiController.class);
+
+    private static final String DISTRIBUTOR_FOR_SPECIFIED_ACTION = ""
+            + "PREFIX : <http://vitro.mannlib.cornell.edu/ns/vitro/ApplicationSetup#> \n" + "SELECT ?distributor  \n" //
+            + "WHERE { \n" //
+            + "   ?distributor :actionName ?action . \n" //
+            + "} \n";
+
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        try {
+            Model model = ModelAccess.on(req).getOntModel(DISPLAY);
+
+            String uri = findDistributorForAction(req, model);
+            DataDistributor instance = instantiateDistributor(req, uri, model);
+            runIt(req, resp, instance);
+        } catch (NoSuchActionException e) {
+            do400BadRequest(e.getMessage(), resp);
+        } catch (MissingParametersException e) {
+            do400BadRequest(e.getMessage(), resp);
+        } catch (NotAuthorizedException e) {
+            do403Forbidden(resp);
+        } catch (Exception e) {
+            do500InternalServerError(e.getMessage(), e, resp);
+        }
+    }
+
+    private String findDistributorForAction(HttpServletRequest req, Model model) throws NoSuchActionException {
+        String action = req.getPathInfo();
+        if (action == null || action.isEmpty()) {
+            throw new NoSuchActionException("'action' path was not provided.");
+        }
+        if (action.startsWith("/")) {
+            action = action.substring(1);
+        }
+
+        return findDistributorUri(model, action);
+    }
+
+    public static String findDistributorUri(Model model, String action) throws NoSuchActionException {
+        List<String> uris = createSelectQueryContext(model, DISTRIBUTOR_FOR_SPECIFIED_ACTION)
+                .bindVariableToPlainLiteral("action", action).execute().toStringFields("distributor").flatten();
+        Collections.sort(uris);
+        log.debug("Found URIs for action '" + action + "': " + uris);
+
+        if (uris.isEmpty()) {
+            throw new NoSuchActionException("Did not find a DataDistributor for '" + action + "'");
+        }
+        if (uris.size() > 1) {
+            log.warn("Found more than one DataDistributor for '" + action + "': " + uris);
+        }
+
+        return uris.get(0);
+    }
+
+    private DataDistributor instantiateDistributor(HttpServletRequest req, String distributorUri, Model model)
+            throws ActionFailedException {
+        try {
+            return new ConfigurationBeanLoader(model, req).loadInstance(distributorUri, DataDistributor.class);
+        } catch (ConfigurationBeanLoaderException e) {
+            throw new ActionFailedException("Failed to instantiate the DataDistributor: " + distributorUri, e);
+        }
+    }
+
+    public static DataDistributor instantiateDistributor(String distributorUri, Model model)
+            throws ActionFailedException {
+        try {
+            return new ConfigurationBeanLoader(model).loadInstance(distributorUri, DataDistributor.class);
+        } catch (ConfigurationBeanLoaderException e) {
+            throw new ActionFailedException("Failed to instantiate the DataDistributor: " + distributorUri, e);
+        }
+    }
+
+    private void runIt(HttpServletRequest req, HttpServletResponse resp, DataDistributor instance)
+            throws DataDistributorException {
+        try {
+            instance.init(new DataDistributorContextImpl(req));
+            log.debug("Distributor is " + instance);
+
+            resp.setContentType(instance.getContentType());
+            resp.setCharacterEncoding("UTF-8");
+            instance.writeOutput(resp.getOutputStream());
+        } catch (Exception e) {
+            log.error("Failed to execute the DataDistributor", e);
+            instance.close();
+            throw new ActionFailedException(e);
+        }
+    }
+
+    private void do400BadRequest(String message, HttpServletResponse resp) throws IOException {
+        log.debug("400BadRequest: " + message);
+        resp.setStatus(400);
+        resp.getWriter().println(message);
+    }
+
+    private void do403Forbidden(HttpServletResponse resp) throws IOException {
+        log.debug("403Forbidden");
+        resp.setStatus(403);
+        resp.getWriter().println("Not authorized for this action.");
+    }
+
+    private void do500InternalServerError(String message, Exception e, HttpServletResponse resp) throws IOException {
+        log.warn("500InternalServerError " + message, e);
+        resp.setStatus(500);
+        try {
+            PrintWriter w = resp.getWriter();
+            w.println(message);
+            e.printStackTrace(w);
+        } catch (IllegalStateException e1) {
+            OutputStream os = resp.getOutputStream();
+            os.write((message + "\n").getBytes());
+            e.printStackTrace(new PrintStream(os));
+        }
+
+    }
+
+    /**
+     * If you want to use a post form, go ahead.
+     */
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        doGet(req, resp);
+    }
+
+}

api/src/main/java/edu/cornell/library/scholars/webapp/controller/api/distribute/AbstractDataDistributor.java

@@ -0,0 +1,30 @@
+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+
+package edu.cornell.library.scholars.webapp.controller.api.distribute;
+
+import java.util.Map;
+
+import edu.cornell.mannlib.vitro.webapp.utils.configuration.Property;
+
+/**
+ * TODO
+ */
+public abstract class AbstractDataDistributor implements DataDistributor {
+    private static final String ACTION_NAME_PROPERTY = "http://vitro.mannlib.cornell.edu/ns/vitro/ApplicationSetup#actionName";
+
+    protected DataDistributorContext ddContext;
+    protected Map<String, String[]> parameters;
+    protected String actionName;
+
+    @Override
+    public void init(DataDistributorContext ddc) throws DataDistributorException {
+        this.ddContext = ddc;
+        this.parameters = ddc.getRequestParameters();
+    }
+
+    @Property(uri = ACTION_NAME_PROPERTY, minOccurs = 1, maxOccurs = 1)
+    public void setActionName(String aName) {
+        this.actionName = aName;
+    }
+
+}