* governing permissions and limitations under the License.
 */
package org.codelibs.core.io;

/**
 * クラスやリソースの集まりを表すオブジェクトです。
 *
 * @author koichik
 * @see TraversalUtil
 */
public interface Traverser {

    /**
     * 指定されたクラス名に対応するクラスファイルがこのインスタンスが扱うリソースの中に存在すれば<code>true</code>を返します。
     * <p>
     * インスタンス構築時にルートパッケージが指定されている場合、 指定されたクラス名はルートパッケージからの相対名として解釈されます。
     * </p>
     *
     * @param className

        final Traverser[] traversers = TraversalUtil.getTraversers("org.codelibs.core.io.xxx");
        assertThat(traversers, is(notNullValue()));
        assertThat(traversers.length, is(1));

        final Traverser traverser = traversers[0];
        assertThat(traverser instanceof FileSystemTraverser, is(true));

        assertThat(traverser.isExistClass("DummyTest"), is(true));

 * implement it:
 *
 * <pre>{@code
 * // won't work
 * TreeTraverser<NodeType> traverser = node -> node.getChildNodes();
 * }</pre>
 *
 * Instead, you can pass a lambda expression to the {@code using} factory method:
 *
 * <pre>{@code
 * TreeTraverser<NodeType> traverser = TreeTraverser.using(node -> node.getChildNodes());
 * }</pre>
 *
 * @author Louis Wasserman
 * @since 15.0

    assertEqualCharNodes(traverser.breadthFirst(charactersOf("acdb")), "acdb");
    assertEqualCharNodes(traverser.breadthFirst(charactersOf("db")), "db");
  }

  @Test
  public void forGraph_breadthFirst_multiGraph() {
    Traverser<Character> traverser = Traverser.forGraph(MULTI_GRAPH);
    assertEqualCharNodes(traverser.breadthFirst('a'), "abcd");

    assertEqualCharNodes(traverser.breadthFirst(charactersOf("acdb")), "acdb");
    assertEqualCharNodes(traverser.breadthFirst(charactersOf("db")), "db");
  }

  @Test
  public void forGraph_breadthFirst_multiGraph() {
    Traverser<Character> traverser = Traverser.forGraph(MULTI_GRAPH);
    assertEqualCharNodes(traverser.breadthFirst('a'), "abcd");

 * @see URLUtil#toCanonicalProtocol(String)
 * @see ClassTraversalUtil
 * @see ResourceTraversalUtil
 */
public abstract class TraversalUtil {

    /** 空の{@link Traverser}の配列です。 */
    protected static final Traverser[] EMPTY_ARRAY = new Traverser[0];

    private static final Logger logger = Logger.getLogger(TraversalUtil.class);

    /** URLのプロトコルをキー、{@link TraverserFactory}を値とするマッピングです。 */

    int dotIndex = fileName.lastIndexOf('.');
    return (dotIndex == -1) ? fileName : fileName.substring(0, dotIndex);
  }

  /**
   * Returns a {@link Traverser} instance for the file and directory tree. The returned traverser
   * starts from a {@link File} and will return all files and directories it encounters.
   *
   * <p><b>Warning:</b> {@code File} provides no support for symbolic links, and as such there is no

      throw e.getCause();
    }
  }

  /**
   * Returns a {@link Traverser} instance for the file and directory tree. The returned traverser
   * starts from a {@link Path} and will return all files and directories it encounters.
   *
   * <p>The returned traverser attempts to avoid following symbolic links to directories. However,
   * the traverser cannot guarantee that it will not follow symbolic links to directories as it is

      throw e.getCause();
    }
  }

  /**
   * Returns a {@link Traverser} instance for the file and directory tree. The returned traverser
   * starts from a {@link Path} and will return all files and directories it encounters.
   *
   * <p>The returned traverser attempts to avoid following symbolic links to directories. However,
   * the traverser cannot guarantee that it will not follow symbolic links to directories as it is

    int dotIndex = fileName.lastIndexOf('.');
    return (dotIndex == -1) ? fileName : fileName.substring(0, dotIndex);
  }

  /**
   * Returns a {@link Traverser} instance for the file and directory tree. The returned traverser
   * starts from a {@link File} and will return all files and directories it encounters.
   *
   * <p><b>Warning:</b> {@code File} provides no support for symbolic links, and as such there is no