Rest api for handle resolution with metadata

dspace-api/src/main/java/org/dspace/handle/HandlePlugin.java

@@ -254,6 +254,54 @@ public void scanNAs(ScanCallback callback) throws HandleException {
     // Resolving methods
     ////////////////////////////////////////
 
+    /**
+     * Resolve the given handle to DSpace object.
+     *
+     * @param context the context
+     * @param handle the handle to resolve
+     * @return the resolved DSpaceObject
+     * @throws HandleException if an error occurs during resolution
+     */
+    private static DSpaceObject resolveHandleToObject(Context context, String handle) throws HandleException {
+        try {
+            return handleClarinService.resolveToObject(context, handle);
+        } catch (Exception e) {
+            if (log.isDebugEnabled()) {
+                log.debug("Exception in resolveHandleToObject", e);
+            }
+            throw new HandleException(HandleException.INTERNAL_ERROR);
+        }
+    }
+
+    /**
+     * Retrieves handle values as a map.
+     *
+     * @param handle the handle to resolve
+     * @return a map containing the handle values
+     * @throws HandleException if an error occurs during handle resolution
+     */
+    public static Map<String, String> getMapHandleValues(String handle) throws HandleException {
+        if (log.isInfoEnabled()) {
+            log.info("Called getMapHandleValues");
+        }
+        loadServices();
+        Context context = new Context();
+        try {
+            DSpaceObject dso = null;
+            boolean resolveMetadata = configurationService.getBooleanProperty("lr.pid.resolvemetadata", true);
+            if (resolveMetadata) {
+                dso = resolveHandleToObject(context, handle);
+            }
+            return extractMetadata(dso);
+        } finally {
+            try {
+                context.complete();
+            } catch (SQLException sqle) {
+                // ignore
+            }
+        }
+    }
+
     /**
      * Return the raw values for this handle. This implementation returns a
      * single URL value.
@@ -285,15 +333,7 @@ public byte[][] getRawHandleValues(byte[] theHandle, int[] indexList,
             String handle = Util.decodeString(theHandle);
 
             context = new Context();
-
-            DSpaceObject dso = null;
             String url = handleClarinService.resolveToURL(context, handle);
-
-            boolean resolveMetadata = configurationService.getBooleanProperty("lr.pid.resolvemetadata", true);
-            if (resolveMetadata) {
-                dso = handleClarinService.resolveToObject(context, handle);
-            }
-
             if (Objects.isNull(url)) {
                 // try with old prefix
 
@@ -332,6 +372,11 @@ public byte[][] getRawHandleValues(byte[] theHandle, int[] indexList,
                 rh = new ResolvedHandle(url, splits[1], splits[2], splits[3], splits[4], splits[5], splits[6],
                         splits[7]);
             } else {
+                DSpaceObject dso = null;
+                boolean resolveMetadata = configurationService.getBooleanProperty("lr.pid.resolvemetadata", true);
+                if (resolveMetadata) {
+                    dso = resolveHandleToObject(context, handle);
+                }
                 rh = new ResolvedHandle(url, dso);
             }
             log.info(String.format("Handle [%s] resolved to [%s]", handle, url));

dspace-server-webapp/src/main/java/org/dspace/app/rest/hdlresolver/HdlResolverRestController.java

@@ -9,15 +9,18 @@
 
 import java.text.MessageFormat;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import javax.servlet.http.HttpServletRequest;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import net.handle.hdllib.HandleException;
 import org.apache.commons.lang.StringUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.dspace.app.rest.utils.ContextUtil;
+import org.dspace.handle.HandlePlugin;
 import org.dspace.handle.hdlresolver.HdlResolverDTO;
 import org.dspace.handle.hdlresolver.HdlResolverService;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -166,13 +169,28 @@ public ResponseEntity<String> listHandles(HttpServletRequest request, @PathVaria
 
     /**
      * Maps the handle to a correct response.
+     * If the metadata parameter is provided, return additional handle values.
      *
      * @param request        HttpServletRequest
      * @param handleResolver HdlResolverDTO - Handle resolver
-     * @return One element list using String if found, else null String.
+     * @return One element list using String if found, else map of metadata if param is entered,
+     * else "null" in case of an error
      */
     private String resolveToURL(HttpServletRequest request, HdlResolverDTO handleResolver) {
-        return mapAsJson(this.hdlResolverService.resolveToURL(ContextUtil.obtainContext(request), handleResolver));
+        String url = this.hdlResolverService.resolveToURL(ContextUtil.obtainContext(request), handleResolver);
+        String param = request.getParameter("metadata");
+        if (StringUtils.isBlank(param)) {
+            return mapAsJson(url);
+        }
+        String handle = handleResolver.getHandle();
+        try {
+            Map<String, String> metadata = HandlePlugin.getMapHandleValues(handle);
+            metadata.put("URL", url);
+            return mapAsJson(metadata);
+        } catch (HandleException e) {
+            log.error("Failed to resolve handle values for handle: " + handle, e);
+        }
+        return "null";
     }
 
     protected String mapAsJson(final String resolvedUrl) {
@@ -183,6 +201,19 @@ protected String mapAsJson(final String resolvedUrl) {
         return json;
     }
 
+    protected String mapAsJson(final Map<String, String> resolvedMap) {
+        ObjectMapper objectMapper = new ObjectMapper();
+        String json = "null";
+        try {
+            if (resolvedMap != null && !resolvedMap.isEmpty()) {
+                json = objectMapper.writeValueAsString(resolvedMap);
+            }
+        } catch (JsonProcessingException e) {
+            log.error("Error during conversion of response!", e);
+        }
+        return json;
+    }
+
     protected String mapAsJson(final List<String> jsonList) {
         String json = "null";
         if (jsonList != null && !jsonList.isEmpty()) {
@@ -194,5 +225,4 @@ protected String mapAsJson(final List<String> jsonList) {
         }
         return json;
     }
-
 }

dspace-server-webapp/src/test/java/org/dspace/app/rest/hdlresolver/HdlResolverRestControllerIT.java

@@ -9,6 +9,7 @@
 
 import static org.hamcrest.Matchers.allOf;
 import static org.hamcrest.Matchers.containsInAnyOrder;
+import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.not;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
@@ -84,7 +85,36 @@ public void givenMappedIdentifierWhenCallHdlresolverThenReturnsMappedURL() throw
         getClient()
             .perform(get("/wrongController/" + publicItem1.getHandle()))
             .andExpect(status().isNotFound());
+    }
+
+    @Test
+    public void givenMappedIdentifierWhenCallHdlresolverThenReturnsMappedParams() throws Exception {
+        context.turnOffAuthorisationSystem();
+
+        // ** START GIVEN **
+        parentCommunity = CommunityBuilder.createCommunity(context).withName("Parent Community").build();
+
+        Collection col1 = CollectionBuilder.createCollection(context, parentCommunity).withName("Collection 1")
+                .withLogo("TestingContentForLogo").build();
 
+        Item publicItem1 = ItemBuilder.createItem(context, col1).withTitle("Public item 1").withIssueDate("2017-10-17")
+                .withAuthor("Smith, Donald").withAuthor("Doe, John").withSubject("ExtraEntry")
+                .withHandle("123456789/testHdlResolver").build();
+
+        context.restoreAuthSystemState();
+
+        // ** END GIVEN **
+        getClient()
+                .perform(get(HdlResolverRestController.RESOLVE  + publicItem1.getHandle())
+                    .param("metadata", "true"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.URL",
+                        StringContains.containsString("123456789/testHdlResolver")))
+                .andExpect(jsonPath("$.TITLE", StringContains.containsString("Public item 1")))
+                .andExpect(jsonPath("$.REPOSITORY", is(configurationService.getProperty("dspace.name"))))
+                .andExpect(jsonPath("$.REPORTEMAIL",
+                        StringContains.containsString("[email protected]")))
+                .andExpect(jsonPath("$.SUBMITDATE").exists());
     }
 
     @Test