WebJarsRoute.java

/**
 * Copyright (C) 2013-2015 all@code-story.net
 *
 * 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 net.codestory.http.routes;

import static java.time.ZonedDateTime.*;
import static java.time.format.DateTimeFormatter.*;
import static java.util.stream.Collectors.toList;
import static net.codestory.http.constants.Headers.*;
import static net.codestory.http.constants.Methods.*;
import static net.codestory.http.io.Strings.extension;
import static org.webjars.WebJarAssetLocator.WEBJARS_PATH_PREFIX;

import java.net.*;
import java.util.*;

import net.codestory.http.*;
import net.codestory.http.io.*;
import net.codestory.http.logs.*;
import net.codestory.http.misc.*;
import net.codestory.http.payload.*;

class WebJarsRoute implements Route {
  private final boolean prodMode;
  private final WebJarUrlFinder webJarUrlFinder;

  public WebJarsRoute(boolean prodMode) {
    this.prodMode = prodMode;
    this.webJarUrlFinder = new WebJarUrlFinder(prodMode);
  }

  @Override
  public boolean matchUri(String uri) {
    if (!uri.startsWith("/webjars/")) {
      // Fail fast
      return false;
    }

    if (getResource(uri) != null) {
      return true;
    }

    if (!prodMode) {
      printKnownWebjars(uri);
    }

    return false;
  }

  private void printKnownWebjars(String wantedUri) {
    String extension = extension(wantedUri);

    List<String> filteredUris = new ClasspathScanner()
      .getResources(WEBJARS_PATH_PREFIX)
      .stream()
      .filter(uri -> uri.endsWith(extension))
      .collect(toList());

    if (!filteredUris.isEmpty()) {
      Logs.printKnownWebjars(filteredUris, extension);
    } else {
      Logs.printUnknownWebjar(wantedUri, extension);
    }
  }

  @Override
  public boolean matchMethod(String method) {
    return GET.equalsIgnoreCase(method) || HEAD.equalsIgnoreCase(method);
  }

  @Override
  public Payload body(Context context) {
    String uri = context.uri();

    URL url = webJarUrlFinder.url(uri);

    return new Payload(url)
      .withHeader(CACHE_CONTROL, "public, max-age=31536000")
      .withHeader(LAST_MODIFIED, RFC_1123_DATE_TIME.format(now().minusMonths(1L)))
      .withHeader(EXPIRES, RFC_1123_DATE_TIME.format(now().plusWeeks(1L)));
  }

  private static URL getResource(String uri) {
    if (uri.endsWith("/")) {
      return null;
    }
    return ClassPaths.getResource("META-INF/resources" + uri);
  }
}