content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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.alibaba.compileflow.engine.core.infrastructure.utils;
  
  import java.io.*;
  
  /**
   * @author yusu
   */
  public class FileUtils {
  
      /**
       * Reads the contents of a file into a byte array.
       */
      public static byte[] readFileToByteArray(final File file) throws IOException {
          try (InputStream in = openInputStream(file)) {
              long fileLength = file.length();
              return fileLength > 0 ? IOUtils.toByteArray(in, fileLength) : IOUtils.toByteArray(in);
          }
      }
  
      public static FileInputStream openInputStream(final File file) throws IOException {
          if (file.exists()) {
              if (file.isDirectory()) {
                  throw new IOException("File '" + file + "' exists but is a directory");
              }
              if (!file.canRead()) {
                  throw new IOException("File '" + file + "' cannot be read");
              }
          } else {
              throw new FileNotFoundException("File '" + file + "' does not exist");
          }
          return new FileInputStream(file);
      }
  
  }
  