Merged in feature/i18n_for_plugins_v2 (pull request #92)

Feature/i18n for plugins v2

scm-webapp/src/main/java/sonia/scm/WebResourceServlet.java

@@ -23,6 +23,7 @@ import java.net.URL;
  * @since 2.0.0
  */
 @Singleton
+@Priority(WebResourceServlet.PRIORITY)
 @WebElement(value = WebResourceServlet.PATTERN, regex = true)
 public class WebResourceServlet extends HttpServlet {
 
@@ -35,6 +36,9 @@ public class WebResourceServlet extends HttpServlet {
   @VisibleForTesting
   static final String PATTERN = "/(?!api/|git/|hg/|svn/|hook/|repo/).*";
 
+  // Be sure that this servlet is the last one in the servlet chain.
+  static final int PRIORITY = Integer.MAX_VALUE;
+
   private static final Logger LOG = LoggerFactory.getLogger(WebResourceServlet.class);
 
   private final WebResourceSender sender = WebResourceSender.create()

scm-webapp/src/main/java/sonia/scm/web/i18n/I18nServlet.java

@@ -0,0 +1,188 @@
+package sonia.scm.web.i18n;
+
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.github.legman.Subscribe;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.inject.Singleton;
+import lombok.extern.slf4j.Slf4j;
+import sonia.scm.NotFoundException;
+import sonia.scm.SCMContext;
+import sonia.scm.Stage;
+import sonia.scm.boot.RestartEvent;
+import sonia.scm.cache.Cache;
+import sonia.scm.cache.CacheManager;
+import sonia.scm.filter.WebElement;
+import sonia.scm.plugin.PluginLoader;
+
+import javax.inject.Inject;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.net.URL;
+import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.Optional;
+import java.util.function.BiConsumer;
+import java.util.function.Function;
+
+
+/**
+ * Collect the plugin translations.
+ */
+@Singleton
+@WebElement(value = I18nServlet.PATTERN, regex = true)
+@Slf4j
+public class I18nServlet extends HttpServlet {
+
+  public static final String PLUGINS_JSON = "plugins.json";
+  public static final String PATTERN = "/locales/[a-z\\-A-Z]*/" + PLUGINS_JSON;
+  public static final String CACHE_NAME = "sonia.cache.plugins.translations";
+
+  private final ClassLoader classLoader;
+  private final Cache<String, JsonNode> cache;
+  private static ObjectMapper objectMapper = new ObjectMapper();
+
+
+  @Inject
+  public I18nServlet(PluginLoader pluginLoader, CacheManager cacheManager) {
+    this.classLoader = pluginLoader.getUberClassLoader();
+    this.cache = cacheManager.getCache(CACHE_NAME);
+  }
+
+  @Subscribe(async = false)
+  public void handleRestartEvent(RestartEvent event) {
+    log.debug("Clear cache on restart event with reason {}", event.getReason());
+    cache.clear();
+  }
+
+  private JsonNode getCollectedJson(String path,
+                                    Function<String, Optional<JsonNode>> jsonFileProvider,
+                                    BiConsumer<String, JsonNode> createdJsonFileConsumer) {
+    return Optional.ofNullable(jsonFileProvider.apply(path)
+      .orElseGet(() -> {
+          Optional<JsonNode> createdFile = collectJsonFile(path);
+          createdFile.ifPresent(map -> createdJsonFileConsumer.accept(path, map));
+          return createdFile.orElse(null);
+        }
+      )).orElseThrow(NotFoundException::new);
+  }
+
+  @VisibleForTesting
+  @Override
+  protected void doGet(HttpServletRequest req, HttpServletResponse response) {
+    try (PrintWriter out = response.getWriter()) {
+      response.setContentType("application/json");
+      String path = req.getServletPath();
+      Function<String, Optional<JsonNode>> jsonFileProvider = usedPath -> Optional.empty();
+      BiConsumer<String, JsonNode> createdJsonFileConsumer = (usedPath, jsonNode) -> log.debug("A json File is created from the path {}", usedPath);
+      if (isProductionStage()) {
+        log.debug("In Production Stage get the plugin translations from the cache");
+        jsonFileProvider = usedPath -> Optional.ofNullable(
+          cache.get(usedPath));
+        createdJsonFileConsumer = createdJsonFileConsumer
+          .andThen((usedPath, jsonNode) -> log.debug("Put the created json File in the cache with the key {}", usedPath))
+          .andThen(cache::put);
+      }
+      objectMapper.writeValue(out, getCollectedJson(path, jsonFileProvider, createdJsonFileConsumer));
+    } catch (IOException e) {
+      log.error("Error on getting the translation of the plugins", e);
+      response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+    } catch (NotFoundException e) {
+      log.error("Plugin translations are not found", e);
+      response.setStatus(HttpServletResponse.SC_NOT_FOUND);
+    }
+  }
+
+  @VisibleForTesting
+  protected boolean isProductionStage() {
+    return SCMContext.getContext().getStage() == Stage.PRODUCTION;
+  }
+
+  /**
+   * Return a collected Json File as JsonNode from the given path from all plugins in the class path
+   *
+   * @param path the searched resource path
+   * @return a collected Json File as JsonNode from the given path from all plugins in the class path
+   */
+  @VisibleForTesting
+  protected Optional<JsonNode> collectJsonFile(String path) {
+    log.debug("Collect plugin translations from path {} for every plugin", path);
+    JsonNode mergedJsonNode = null;
+    try {
+      Enumeration<URL> resources = classLoader.getResources(path.replaceFirst("/", ""));
+      while (resources.hasMoreElements()) {
+        URL url = resources.nextElement();
+        JsonNode jsonNode = objectMapper.readTree(url);
+        if (mergedJsonNode != null) {
+          merge(mergedJsonNode, jsonNode);
+        } else {
+          mergedJsonNode = jsonNode;
+        }
+      }
+    } catch (IOException e) {
+      log.error("Error on loading sources from {}", path, e);
+      return Optional.empty();
+    }
+    return Optional.ofNullable(mergedJsonNode);
+  }
+
+
+  /**
+   * Merge the <code>updateNode</code> into the <code>mainNode</code> and return it.
+   *
+   * This is not a deep merge.
+   *
+   * @param mainNode the main node
+   * @param updateNode the update node
+   * @return the merged mainNode
+   */
+  @VisibleForTesting
+  protected JsonNode merge(JsonNode mainNode, JsonNode updateNode) {
+    Iterator<String> fieldNames = updateNode.fieldNames();
+
+    while (fieldNames.hasNext()) {
+
+      String fieldName = fieldNames.next();
+      JsonNode jsonNode = mainNode.get(fieldName);
+
+      if (jsonNode != null) {
+        mergeNode(updateNode, fieldName, jsonNode);
+      } else {
+        mergeField(mainNode, updateNode, fieldName);
+      }
+    }
+    return mainNode;
+  }
+
+  private void mergeField(JsonNode mainNode, JsonNode updateNode, String fieldName) {
+    if (mainNode instanceof ObjectNode) {
+      JsonNode value = updateNode.get(fieldName);
+      if (value.isNull()) {
+        return;
+      }
+      if (value.isIntegralNumber() && value.toString().equals("0")) {
+        return;
+      }
+      if (value.isFloatingPointNumber() && value.toString().equals("0.0")) {
+        return;
+      }
+      ((ObjectNode) mainNode).set(fieldName, value);
+    }
+  }
+
+  private void mergeNode(JsonNode updateNode, String fieldName, JsonNode jsonNode) {
+    if (jsonNode.isObject()) {
+      merge(jsonNode, updateNode.get(fieldName));
+    } else if (jsonNode.isArray()) {
+      for (int i = 0; i < jsonNode.size(); i++) {
+        merge(jsonNode.get(i), updateNode.get(fieldName).get(i));
+      }
+    }
+  }
+
+}