1 files changed, 120 insertions, 0 deletions
diff --git a/java/com/google/gerrit/pgm/init/InitPluginStepsLoader.java b/java/com/google/gerrit/pgm/init/InitPluginStepsLoader.java
new file mode 100644
index 0000000000..a7f9c5d543
--- /dev/null
+++ b/java/com/google/gerrit/pgm/init/InitPluginStepsLoader.java
@@ -0,0 +1,120 @@
+// Copyright (C) 2012 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.pgm.init;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.ImmutableList;
+import com.google.gerrit.extensions.annotations.PluginName;
+import com.google.gerrit.pgm.init.api.ConsoleUI;
+import com.google.gerrit.pgm.init.api.InitStep;
+import com.google.gerrit.server.config.SitePaths;
+import com.google.gerrit.server.plugins.JarPluginProvider;
+import com.google.gerrit.server.plugins.PluginUtil;
+import com.google.inject.AbstractModule;
+import com.google.inject.Inject;
+import com.google.inject.Injector;
+import com.google.inject.Singleton;
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.jar.Attributes;
+import java.util.jar.JarFile;
+
+@Singleton
+public class InitPluginStepsLoader {
+  private final Path pluginsDir;
+  private final Injector initInjector;
+  final ConsoleUI ui;
+
+  @Inject
+  public InitPluginStepsLoader(final ConsoleUI ui, SitePaths sitePaths, Injector initInjector) {
+    this.pluginsDir = sitePaths.plugins_dir;
+    this.initInjector = initInjector;
+    this.ui = ui;
+  }
+
+  public Collection<InitStep> getInitSteps() {
+    List<Path> jars = scanJarsInPluginsDirectory();
+    ArrayList<InitStep> pluginsInitSteps = new ArrayList<>();
+
+    for (Path jar : jars) {
+      InitStep init = loadInitStep(jar);
+      if (init != null) {
+        pluginsInitSteps.add(init);
+      }
+    }
+    return pluginsInitSteps;
+  }
+
+  private InitStep loadInitStep(Path jar) {
+    try {
+      URLClassLoader pluginLoader =
+          URLClassLoader.newInstance(
+              new URL[] {jar.toUri().toURL()}, InitPluginStepsLoader.class.getClassLoader());
+      try (JarFile jarFile = new JarFile(jar.toFile())) {
+        Attributes jarFileAttributes = jarFile.getManifest().getMainAttributes();
+        String initClassName = jarFileAttributes.getValue("Gerrit-InitStep");
+        if (initClassName == null) {
+          return null;
+        }
+        @SuppressWarnings("unchecked")
+        Class<? extends InitStep> initStepClass =
+            (Class<? extends InitStep>) pluginLoader.loadClass(initClassName);
+        return getPluginInjector(jar).getInstance(initStepClass);
+      } catch (ClassCastException e) {
+        ui.message(
+            "WARN: InitStep from plugin %s does not implement %s (Exception: %s)\n",
+            jar.getFileName(), InitStep.class.getName(), e.getMessage());
+        return null;
+      } catch (NoClassDefFoundError e) {
+        ui.message(
+            "WARN: Failed to run InitStep from plugin %s (Missing class: %s)\n",
+            jar.getFileName(), e.getMessage());
+        return null;
+      }
+    } catch (Exception e) {
+      ui.message(
+          "WARN: Cannot load and get plugin init step for %s (Exception: %s)\n",
+          jar, e.getMessage());
+      return null;
+    }
+  }
+
+  private Injector getPluginInjector(Path jarPath) throws IOException {
+    final String pluginName =
+        MoreObjects.firstNonNull(
+            JarPluginProvider.getJarPluginName(jarPath), PluginUtil.nameOf(jarPath));
+    return initInjector.createChildInjector(
+        new AbstractModule() {
+          @Override
+          protected void configure() {
+            bind(String.class).annotatedWith(PluginName.class).toInstance(pluginName);
+          }
+        });
+  }
+
+  private List<Path> scanJarsInPluginsDirectory() {
+    try {
+      return PluginUtil.listPlugins(pluginsDir, ".jar");
+    } catch (IOException e) {
+      ui.message("WARN: Cannot list %s: %s", pluginsDir.toAbsolutePath(), e.getMessage());
+      return ImmutableList.of();
+    }
+  }
+}