001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.fs;
019
020import java.io.IOException;
021
022/**
023 * Exceptions based on standard posix/linux style exceptions for path related
024 * errors. Returns an exception with the format "path: standard error string".
025 * 
026 * This exception corresponds to Error Input/ouput(EIO)
027 */
028public class PathIOException extends IOException {
029  static final long serialVersionUID = 0L;
030  private static final String EIO = "Input/output error";
031  // NOTE: this really should be a Path, but a Path is buggy and won't
032  // return the exact string used to construct the path, and it mangles
033  // uris with no authority
034  private String operation;
035  private String path;
036  private String targetPath;
037
038  /**
039   * Constructor a generic I/O error exception
040   *  @param path for the exception
041   */
042  public PathIOException(String path) {
043    this(path, EIO);
044  }
045
046  /**
047   * Appends the text of a Throwable to the default error message
048   * @param path for the exception
049   * @param cause a throwable to extract the error message
050   */
051  public PathIOException(String path, Throwable cause) {
052    this(path, EIO, cause);
053  }
054
055  /**
056   * Avoid using this method.  Use a subclass of PathIOException if
057   * possible.
058   * @param path for the exception
059   * @param error custom string to use an the error text
060   */
061  public PathIOException(String path, String error) {
062    super(error);
063    this.path = path;
064  }
065
066  protected PathIOException(String path, String error, Throwable cause) {
067    super(error, cause);
068    this.path = path;
069  }
070
071  /** Format:
072   * cmd: {operation} `path' {to `target'}: error string
073   */
074  @Override
075  public String getMessage() {
076    StringBuilder message = new StringBuilder();
077    if (operation != null) {
078      message.append(operation + " ");
079    }
080    message.append(formatPath(path));
081    if (targetPath != null) {
082      message.append(" to " + formatPath(targetPath));
083    }
084    message.append(": " + super.getMessage());
085    if (getCause() != null) {
086      message.append(": " + getCause().getMessage());
087    }
088    return message.toString();
089  }
090
091  /** @return Path that generated the exception */
092  public Path getPath()  { return new Path(path); }
093
094  /** @return Path if the operation involved copying or moving, else null */
095  public Path getTargetPath() {
096    return (targetPath != null) ? new Path(targetPath) : null;
097  }    
098  
099  /**
100   * Optional operation that will preface the path
101   * @param operation a string
102   */
103  public void setOperation(String operation) {
104    this.operation = operation;
105  }
106  
107  /**
108   * Optional path if the exception involved two paths, ex. a copy operation
109   * @param targetPath the of the operation
110   */
111  public void setTargetPath(String targetPath) {
112    this.targetPath = targetPath;
113  }
114  
115  private String formatPath(String path) {
116    return "`" + path + "'";
117  }
118}