LinkImpl: avoid redundant repository lookups

bundles/core/src/main/java/com/adobe/cq/wcm/core/components/internal/link/LinkBuilderImpl.java

@@ -15,7 +15,6 @@
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 package com.adobe.cq.wcm.core.components.internal.link;
 
-import java.io.UnsupportedEncodingException;
 import java.math.BigInteger;
 import java.net.URLDecoder;
 import java.nio.charset.StandardCharsets;
@@ -145,16 +144,41 @@ public LinkBuilderImpl(String url, SlingHttpServletRequest req, List<PathProcess
             linkUrl = targetAsset.getPath();
         }
 
-        Asset asset = getAsset(linkUrl);
-        Page page = getPage(linkUrl).orElse(null);
+        // linkUrl can be also set via the linkConfiguration, so we have to resolve it from the generic
+        // resource as well; but try to avoid duplicate resolutions as much as possible.
+        Asset asset = null;
+        Page page = null;
+
+        if (targetAsset != null) {
+        	asset = targetAsset;
+        } else if (targetPage != null) {
+        	page = targetPage;
+        } else {
+        	asset = getAsset(linkUrl);
+        	page = getPage(linkUrl).orElse(null);
+        }
+
+        boolean isExternalUrl = false; 
         if (asset != null) {
             this.reference = asset;
         } else if (page != null) {
             Pair<Page, String> pair = resolvePage(page);
             this.reference = pair.getLeft();
             linkUrl = StringUtils.isNotEmpty(pair.getRight()) ? pair.getRight() : linkUrl;
+
+            // resolvePage() can resolve the linkUrl into an external URL; this can happen when
+            // there is a redirect from the page to an external URL; in this case
+            // the pair is not equivalent
+            isExternalUrl = !pair.getLeft().getPath().equals(linkUrl);
         }
-        String resolvedLinkURL = validateAndResolveLinkURL(linkUrl);
+
+        String resolvedLinkURL = null;
+        if (this.reference != null && page != null && !isExternalUrl) {
+        	resolvedLinkURL = getPageLinkURL((Page)this.reference);
+        } else if (StringUtils.isNotEmpty(linkUrl)) {
+        	resolvedLinkURL = linkUrl;
+        } 
+
         Map<String, String> htmlAttributes = mapLinkAttributesToHtml();
         return buildLink(resolvedLinkURL, request, htmlAttributes);
     }
@@ -228,34 +252,6 @@ private String validateLinkAttributeValue(@Nullable final String value) {
                 .orElse(null);
     }
 
-    /**
-     * Validates and resolves a link URL.
-     *
-     * @param linkURL Link URL
-     * @return The validated link URL or {@code null} if not valid
-     */
-    @Nullable
-    private String validateAndResolveLinkURL(@Nullable final String linkURL) {
-        return Optional.ofNullable(linkURL)
-                .filter(StringUtils::isNotEmpty)
-                .map(this::getLinkURL)
-                .orElse(null);
-    }
-
-    /**
-     * If the provided {@code path} identifies a {@link Page}, this method will generate the correct URL for the page. Otherwise the
-     * original {@code String} is returned.
-     * @param path the page path
-     *
-     * @return the URL of the page identified by the provided {@code path}, or the original {@code path} if this doesn't identify a {@link Page}
-     */
-    @NotNull
-    private String getLinkURL(@NotNull String path) {
-        return getPage(path)
-                .map(this::getPageLinkURL)
-                .orElse(path);
-    }
-
     /**
      * Given a {@link Page}, this method returns the correct URL with the extension
      * @param page the page

bundles/core/src/test/java/com/adobe/cq/wcm/core/components/internal/link/LinkBuilderImplTest.java

@@ -26,6 +26,8 @@
 
 import com.adobe.cq.wcm.core.components.commons.link.Link;
 import com.adobe.cq.wcm.core.components.services.link.PathProcessor;
+import com.day.cq.dam.api.Asset;
+
 import io.wcm.testing.mock.aem.junit5.AemContext;
 import io.wcm.testing.mock.aem.junit5.AemContextExtension;
 
@@ -99,4 +101,20 @@ void testLinkToPage(String given, String expected, String passedDownToPathProces
         verify(pathProcessor).externalize(eq(passedDownToPathProcessor), any());
         verify(pathProcessor).sanitize(eq(passedDownToPathProcessor), any());
     }
+
+
+    void testLinkToAsset() {
+    	Asset asset = context.create().asset("/content/dam/asset.jpg", 0, 0, "image/jpeg");
+
+    	Link link = new LinkBuilderImpl(asset, context.request(),Collections.singletonList(pathProcessor)).build();
+    	assertEquals("/content/dam/asset.jpg", link.getURL());
+    	assertNotNull(link.getReference());
+    	assertEquals(asset,link.getReference());
+
+    	link = new LinkBuilderImpl("/content/dam/asset.jpg", context.request(), Collections.singletonList(pathProcessor),false).build();
+    	assertEquals("/content/dam/asset.jpg", link.getURL());
+    	assertEquals("/content/dam/asset.jpg", ((Asset) link.getReference()).getPath());
+
+
+    }
 }