Source code

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,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.common;
020
021import org.apache.reef.util.Optional;
022
023import java.io.PrintWriter;
024import java.io.StringWriter;
025
026/**
027 * Common data and functionality for all error messages in REEF.
028 */
029public abstract class AbstractFailure implements Failure {
030
031  /**
032   * Identifier of the entity that produced the error. Cannot be null.
033   */
034  private final String id;
035
036  /**
037   * One-line error message. For wrapped exceptions, this equals
038   * to the Exception.getMessage() result. Cannot be null.
039   */
040  private final String message;
041
042  /**
043   * Optional error description (long).
044   * For exceptions it is by default populates with the stack trace.
045   */
046  private final Optional<String> description;
047
048  /**
049   * Optional Java exception that caused the error.
050   */
051  private final Optional<Throwable> cause;
052
053  /**
054   * Optional byte array that contains serialized version of the exception.
055   */
056  private final Optional<byte[]> data;
057
058  /**
059   * @param id          Identifier of the entity that produced the error. Cannot be null.
060   * @param message     One-line error message. Cannot be null.
061   * @param description Long error description. Can be null.
062   * @param cause       Java Exception that caused the error. Can be null.
063   * @param data        byte array that contains serialized version of the error. Can be null.
064   */
065  protected AbstractFailure(final String id,
066                            final String message,
067                            final Optional<String> description,
068                            final Optional<Throwable> cause,
069                            final Optional<byte[]> data) {
070    this.id = id;
071    this.message = message;
072    this.description = description;
073    this.cause = cause;
074    this.data = data;
075  }
076
077
078  /**
079   * Helper function: produce the string that contains the given exception's stack trace.
080   * Returns null if the argument is null.
081   *
082   * @param cause Java Exception or null.
083   * @return A string that contains the exception stack trace, or null.
084   */
085  protected static String getStackTrace(final Throwable cause) {
086    if (cause == null) {
087      return null;
088    } else {
089      final StringWriter writer = new StringWriter();
090      cause.printStackTrace(new PrintWriter(writer));
091      return writer.toString();
092    }
093  }
094
095  /**
096   * @return Identifier of the entity that produced the error. Never null.
097   */
098  @Override
099  public String getId() {
100    return this.id;
101  }
102
103  /**
104   * @return One-line error message. Never null.
105   */
106  @Override
107  public String getMessage() {
108    return this.message;
109  }
110
111  /**
112   * @return Optional long error description. For Java Exceptions, can contain stack trace.
113   */
114  @Override
115  public Optional<String> getDescription() {
116    return this.description;
117  }
118
119  @Override
120  public Optional<Throwable> getReason() {
121    return this.cause;
122  }
123
124  /**
125   * @return Optional serialized version of the error message.
126   */
127  @Override
128  public Optional<byte[]> getData() {
129    return this.data;
130  }
131
132  /**
133   * Return the original Java Exception, or generate a new one if it does not exists.
134   * ALWAYS returns an exception.
135   * FIXME: Replace RuntimeException with a better class.
136   *
137   * @return A java exception. Never null.
138   */
139  @Override
140  public Throwable asError() {
141    return this.cause.isPresent() ? this.cause.get() : new RuntimeException(this.toString());
142  }
143
144  /**
145   * @return Human-readable string representation of an error message.
146   */
147  @Override
148  public String toString() {
149    return this.getClass().getName() + " id=" + this.getId() + " failed: " + this.getMessage();
150  }
151}