content: /*
   * Copyright (c) 2007, 2009, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package java.nio.file;
  
  import java.io.IOException;
  
  /**
   * Thrown when a file system operation fails on one or two files. This class is
   * the general class for file system exceptions.
   *
   * @since 1.7
   */
  
  public class FileSystemException
      extends IOException
  {
      static final long serialVersionUID = -3055425747967319812L;
  
      private final String file;
      private final String other;
  
      /**
       * Constructs an instance of this class. This constructor should be used
       * when an operation involving one file fails and there isn't any additional
       * information to explain the reason.
       *
       * @param   file
       *          a string identifying the file or {@code null} if not known.
       */
      public FileSystemException(String file) {
          super((String)null);
          this.file = file;
          this.other = null;
      }
  
      /**
       * Constructs an instance of this class. This constructor should be used
       * when an operation involving two files fails, or there is additional
       * information to explain the reason.
       *
       * @param   file
       *          a string identifying the file or {@code null} if not known.
       * @param   other
       *          a string identifying the other file or {@code null} if there
       *          isn't another file or if not known
       * @param   reason
       *          a reason message with additional information or {@code null}
       */
      public FileSystemException(String file, String other, String reason) {
          super(reason);
          this.file = file;
          this.other = other;
      }
  
      /**
       * Returns the file used to create this exception.
       *
       * @return  the file (can be {@code null})
       */
      public String getFile() {
          return file;
      }
  
      /**
       * Returns the other file used to create this exception.
       *
       * @return  the other file (can be {@code null})
       */
      public String getOtherFile() {
          return other;
      }
  
      /**
       * Returns the string explaining why the file system operation failed.
       *
       * @return  the string explaining why the file system operation failed
       */
      public String getReason() {
          return super.getMessage();
      }
  
      /**
       * Returns the detail message string.
       */
      @Override
      public String getMessage() {
          if (file == null && other == null)
              return getReason();
          StringBuilder sb = new StringBuilder();
          if (file != null)
              sb.append(file);
          if (other != null) {
              sb.append(" -> ");
              sb.append(other);
          }
          if (getReason() != null) {
              sb.append(": ");
              sb.append(getReason());
          }
          return sb.toString();
      }
  }
  