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, null);
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    this(path, error, null);
063  }
064
065  protected PathIOException(String path, String error, Throwable cause) {
066    super(error, cause);
067    this.path = path;
068  }
069
070  /** Format:
071   * cmd: {operation} `path' {to `target'}: error string
072   */
073  @Override
074  public String getMessage() {
075    StringBuilder message = new StringBuilder();
076    if (operation != null) {
077      message.append(operation + " ");
078    }
079    message.append(formatPath(path));
080    if (targetPath != null) {
081      message.append(" to " + formatPath(targetPath));
082    }
083    message.append(": " + super.getMessage());
084    if (getCause() != null) {
085      message.append(": " + getCause().getMessage());
086    }
087    return message.toString();
088  }
089
090  /** @return Path that generated the exception */
091  public Path getPath()  { return new Path(path); }
092
093  /** @return Path if the operation involved copying or moving, else null */
094  public Path getTargetPath() {
095    return (targetPath != null) ? new Path(targetPath) : null;
096  }    
097  
098  /**
099   * Optional operation that will preface the path
100   * @param operation a string
101   */
102  public void setOperation(String operation) {
103    this.operation = operation;
104  }
105  
106  /**
107   * Optional path if the exception involved two paths, ex. a copy operation
108   * @param targetPath the of the operation
109   */
110  public void setTargetPath(String targetPath) {
111    this.targetPath = targetPath;
112  }
113  
114  private String formatPath(String path) {
115    return "`" + path + "'";
116  }
117}