content: /*
   * Copyright 2002-2018 the original author or authors.
   *
   * 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
   *
   *      https://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.alibaba.nacos.common.packagescan.resource;
  
  import com.alibaba.nacos.common.utils.ReflectUtils;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.lang.reflect.Field;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.net.URI;
  import java.net.URL;
  
  /**
   * Copy from https://github.com/spring-projects/spring-framework.git, with less modifications
   * Utility for detecting and accessing JBoss VFS in the classpath.
   *
   * <p>As of Spring 4.0, this class supports VFS 3.x on JBoss AS 6+
   * (package {@code org.jboss.vfs}) and is in particular compatible with
   * JBoss AS 7 and WildFly 8+.
   *
   * <p>Thanks go to Marius Bogoevici for the initial patch.
   * <b>Note:</b> This is an internal class and should not be used outside the framework.
   *
   * @author Costin Leau
   * @author Juergen Hoeller
   * @since 3.0.3
   */
  public abstract class VfsUtils {
  
      private static final String VFS3_PKG = "org.jboss.vfs.";
  
      private static final String VFS_NAME = "VFS";
  
      private static final Method VFS_METHOD_GET_ROOT_URL;
  
      private static final Method VFS_METHOD_GET_ROOT_URI;
  
      private static final Method VIRTUAL_FILE_METHOD_EXISTS;
  
      private static final Method VIRTUAL_FILE_METHOD_GET_INPUT_STREAM;
  
      private static final Method VIRTUAL_FILE_METHOD_GET_SIZE;
  
      private static final Method VIRTUAL_FILE_METHOD_GET_LAST_MODIFIED;
  
      private static final Method VIRTUAL_FILE_METHOD_TO_URL;
  
      private static final Method VIRTUAL_FILE_METHOD_TO_URI;
  
      private static final Method VIRTUAL_FILE_METHOD_GET_NAME;
  
      private static final Method VIRTUAL_FILE_METHOD_GET_PATH_NAME;
  
      private static final Method VIRTUAL_FILE_METHOD_GET_PHYSICAL_FILE;
  
      private static final Method VIRTUAL_FILE_METHOD_GET_CHILD;
  
      protected static final Class<?> VIRTUAL_FILE_VISITOR_INTERFACE;
  
      protected static final Method VIRTUAL_FILE_METHOD_VISIT;
  
      private static final Field VISITOR_ATTRIBUTES_FIELD_RECURSE;
  
      static {
          ClassLoader loader = VfsUtils.class.getClassLoader();
          try {
              Class<?> vfsClass = loader.loadClass(VFS3_PKG + VFS_NAME);
              VFS_METHOD_GET_ROOT_URL = vfsClass.getMethod("getChild", URL.class);
              VFS_METHOD_GET_ROOT_URI = vfsClass.getMethod("getChild", URI.class);
  
              Class<?> virtualFile = loader.loadClass(VFS3_PKG + "VirtualFile");
              VIRTUAL_FILE_METHOD_EXISTS = virtualFile.getMethod("exists");
              VIRTUAL_FILE_METHOD_GET_INPUT_STREAM = virtualFile.getMethod("openStream");
              VIRTUAL_FILE_METHOD_GET_SIZE = virtualFile.getMethod("getSize");
              VIRTUAL_FILE_METHOD_GET_LAST_MODIFIED = virtualFile.getMethod("getLastModified");
              VIRTUAL_FILE_METHOD_TO_URI = virtualFile.getMethod("toURI");
              VIRTUAL_FILE_METHOD_TO_URL = virtualFile.getMethod("toURL");
              VIRTUAL_FILE_METHOD_GET_NAME = virtualFile.getMethod("getName");
              VIRTUAL_FILE_METHOD_GET_PATH_NAME = virtualFile.getMethod("getPathName");
              VIRTUAL_FILE_METHOD_GET_PHYSICAL_FILE = virtualFile.getMethod("getPhysicalFile");
              VIRTUAL_FILE_METHOD_GET_CHILD = virtualFile.getMethod("getChild", String.class);
  
              VIRTUAL_FILE_VISITOR_INTERFACE = loader.loadClass(VFS3_PKG + "VirtualFileVisitor");
              VIRTUAL_FILE_METHOD_VISIT = virtualFile.getMethod("visit", VIRTUAL_FILE_VISITOR_INTERFACE);
  
              Class<?> visitorAttributesClass = loader.loadClass(VFS3_PKG + "VisitorAttributes");
              VISITOR_ATTRIBUTES_FIELD_RECURSE = visitorAttributesClass.getField("RECURSE");
          } catch (Throwable ex) {
              throw new IllegalStateException("Could not detect JBoss VFS infrastructure", ex);
          }
      }
  
      protected static Object invokeVfsMethod(Method method, Object target, Object... args) throws IOException {
          try {
              return method.invoke(target, args);
          } catch (InvocationTargetException ex) {
              Throwable targetEx = ex.getTargetException();
              if (targetEx instanceof IOException) {
                  throw (IOException) targetEx;
              }
              ReflectUtils.handleInvocationTargetException(ex);
          } catch (Exception ex) {
              ReflectUtils.handleReflectionException(ex);
          }
  
          throw new IllegalStateException("Invalid code path reached");
      }
  
      static boolean exists(Object vfsResource) {
          try {
              return (Boolean) invokeVfsMethod(VIRTUAL_FILE_METHOD_EXISTS, vfsResource);
          } catch (IOException ex) {
              return false;
          }
      }
  
      static boolean isReadable(Object vfsResource) {
          try {
              return (Long) invokeVfsMethod(VIRTUAL_FILE_METHOD_GET_SIZE, vfsResource) > 0;
          } catch (IOException ex) {
              return false;
          }
      }
  
      static long getSize(Object vfsResource) throws IOException {
          return (Long) invokeVfsMethod(VIRTUAL_FILE_METHOD_GET_SIZE, vfsResource);
      }
  
      static long getLastModified(Object vfsResource) throws IOException {
          return (Long) invokeVfsMethod(VIRTUAL_FILE_METHOD_GET_LAST_MODIFIED, vfsResource);
      }
  
      static InputStream getInputStream(Object vfsResource) throws IOException {
          return (InputStream) invokeVfsMethod(VIRTUAL_FILE_METHOD_GET_INPUT_STREAM, vfsResource);
      }
  
      static URL getUrl(Object vfsResource) throws IOException {
          return (URL) invokeVfsMethod(VIRTUAL_FILE_METHOD_TO_URL, vfsResource);
      }
  
      static URI getUri(Object vfsResource) throws IOException {
          return (URI) invokeVfsMethod(VIRTUAL_FILE_METHOD_TO_URI, vfsResource);
      }
  
      static String getName(Object vfsResource) {
          try {
              return (String) invokeVfsMethod(VIRTUAL_FILE_METHOD_GET_NAME, vfsResource);
          } catch (IOException ex) {
              throw new IllegalStateException("Cannot get resource name", ex);
          }
      }
  
      static Object getRelative(URL url) throws IOException {
          return invokeVfsMethod(VFS_METHOD_GET_ROOT_URL, null, url);
      }
  
      static Object getChild(Object vfsResource, String path) throws IOException {
          return invokeVfsMethod(VIRTUAL_FILE_METHOD_GET_CHILD, vfsResource, path);
      }
  
      static File getFile(Object vfsResource) throws IOException {
          return (File) invokeVfsMethod(VIRTUAL_FILE_METHOD_GET_PHYSICAL_FILE, vfsResource);
      }
  
      static Object getRoot(URI url) throws IOException {
          return invokeVfsMethod(VFS_METHOD_GET_ROOT_URI, null, url);
      }
  
      // protected methods used by the support sub-package
  
      protected static Object getRoot(URL url) throws IOException {
          return invokeVfsMethod(VFS_METHOD_GET_ROOT_URL, null, url);
      }
  
      protected static Object doGetVisitorAttributes() {
          return ReflectUtils.getField(VISITOR_ATTRIBUTES_FIELD_RECURSE, null);
      }
  
      protected static String doGetPath(Object resource) {
          return (String) ReflectUtils.invokeMethod(VIRTUAL_FILE_METHOD_GET_PATH_NAME, resource);
      }
  
  }
  