[sling-org-apache-sling-feature-launcher] 01/01: SLING-8483 - Added a priority to the Extension Handler to find the most suitable one

[an...@apache.org]

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andysch pushed a commit to branch issues/SLING-8483
in repository https://gitbox.apache.org/repos/asf/sling-org-apache-sling-feature-launcher.git

commit 5279ad5da677be9191903302a4a102d58094e1dd
Author: Andreas Schaefer <sc...@iMac.local>
AuthorDate: Tue Aug 20 14:52:56 2019 -0700

    SLING-8483 - Added a priority to the Extension Handler to find the most suitable one
---
 .../apache/sling/feature/launcher/impl/FeatureProcessor.java  | 11 ++++++++++-
 .../impl/extensions/handlers/ContentPackageHandler.java       |  5 +++++
 .../launcher/impl/extensions/handlers/RepoInitHandler.java    |  5 +++++
 .../feature/launcher/spi/extensions/ExtensionHandler.java     |  6 ++++++
 4 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/main/java/org/apache/sling/feature/launcher/impl/FeatureProcessor.java b/src/main/java/org/apache/sling/feature/launcher/impl/FeatureProcessor.java
index 68facce..2fd5bc7 100644
--- a/src/main/java/org/apache/sling/feature/launcher/impl/FeatureProcessor.java
+++ b/src/main/java/org/apache/sling/feature/launcher/impl/FeatureProcessor.java
@@ -21,11 +21,13 @@ import java.io.InputStreamReader;
 import java.io.Reader;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import java.util.ServiceLoader;
 import java.util.Spliterator;
 import java.util.Spliterators;
+import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
 
 import org.apache.sling.feature.Artifact;
@@ -163,7 +165,14 @@ public class FeatureProcessor {
         }
 
         extensions: for(final Extension ext : app.getExtensions()) {
-            for (ExtensionHandler handler : ServiceLoader.load(ExtensionHandler.class,  FeatureProcessor.class.getClassLoader()))
+            List<ExtensionHandler> extensionHandlerList = new ArrayList<>();
+            for (ExtensionHandler handler : ServiceLoader.load(ExtensionHandler.class,  FeatureProcessor.class.getClassLoader())) {
+                extensionHandlerList.add(handler);
+            }
+            List<ExtensionHandler> prioritizedExtensionHandlerList = extensionHandlerList.stream()
+                .sorted(Comparator.comparingInt(ExtensionHandler::getPriority).reversed())
+                .collect(Collectors.toList());
+            for (ExtensionHandler handler : prioritizedExtensionHandlerList)
             {
                 if (handler.handle(new ExtensionContextImpl(ctx, config.getInstallation(), loadedFeatures), ext)) {
                     continue extensions;
diff --git a/src/main/java/org/apache/sling/feature/launcher/impl/extensions/handlers/ContentPackageHandler.java b/src/main/java/org/apache/sling/feature/launcher/impl/extensions/handlers/ContentPackageHandler.java
index a08061c..825be67 100644
--- a/src/main/java/org/apache/sling/feature/launcher/impl/extensions/handlers/ContentPackageHandler.java
+++ b/src/main/java/org/apache/sling/feature/launcher/impl/extensions/handlers/ContentPackageHandler.java
@@ -27,6 +27,11 @@ import org.apache.sling.feature.launcher.spi.extensions.ExtensionHandler;
 public class ContentPackageHandler implements ExtensionHandler
 {
     @Override
+    public int getPriority() {
+        return FALLBACK_PRIORITY;
+    }
+
+    @Override
     public boolean handle(ExtensionContext context, Extension extension) throws IOException
     {
         if (extension.getType() == ExtensionType.ARTIFACTS
diff --git a/src/main/java/org/apache/sling/feature/launcher/impl/extensions/handlers/RepoInitHandler.java b/src/main/java/org/apache/sling/feature/launcher/impl/extensions/handlers/RepoInitHandler.java
index 34ac652..329148a 100644
--- a/src/main/java/org/apache/sling/feature/launcher/impl/extensions/handlers/RepoInitHandler.java
+++ b/src/main/java/org/apache/sling/feature/launcher/impl/extensions/handlers/RepoInitHandler.java
@@ -29,6 +29,11 @@ public class RepoInitHandler implements ExtensionHandler
     private static final AtomicInteger index = new AtomicInteger(1);
 
     @Override
+    public int getPriority() {
+        return FALLBACK_PRIORITY;
+    }
+
+    @Override
     public boolean handle(ExtensionContext context, Extension extension) throws Exception
     {
         if (extension.getName().equals(Extension.EXTENSION_NAME_REPOINIT)) {
diff --git a/src/main/java/org/apache/sling/feature/launcher/spi/extensions/ExtensionHandler.java b/src/main/java/org/apache/sling/feature/launcher/spi/extensions/ExtensionHandler.java
index acb8347..a4cef73 100644
--- a/src/main/java/org/apache/sling/feature/launcher/spi/extensions/ExtensionHandler.java
+++ b/src/main/java/org/apache/sling/feature/launcher/spi/extensions/ExtensionHandler.java
@@ -20,5 +20,11 @@ import org.apache.sling.feature.Extension;
 
 public interface ExtensionHandler
 {
+    /** Priority for Extension Handlers that are just a fallback instance **/
+    int FALLBACK_PRIORITY = -1;
+
+    /** @return The priority of the Extension Handler to select the most appropriate one. The one with the highest priority is selected **/
+    int getPriority();
+
     public boolean handle(ExtensionContext context, Extension extension) throws Exception;
 }