View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.lang3.exception;
18  
19  import java.util.List;
20  import java.util.Set;
21  
22  import org.apache.commons.lang3.tuple.Pair;
23  
24  /**
25   * A runtime exception that provides an easy and safe way to add contextual information.
26   * <p>
27   * An exception trace itself is often insufficient to provide rapid diagnosis of the issue.
28   * Frequently what is needed is a select few pieces of local contextual data.
29   * Providing this data is tricky however, due to concerns over formatting and nulls.
30   * </p><p>
31   * The contexted exception approach allows the exception to be created together with a
32   * list of context label-value pairs. This additional information is automatically included in
33   * the message and printed stack trace.
34   * </p><p>
35   * A checked version of this exception is provided by ContextedException.
36   * </p>
37   * <p>
38   * To use this class write code as follows:
39   * </p>
40   * <pre>
41   *   try {
42   *     ...
43   *   } catch (Exception e) {
44   *     throw new ContextedRuntimeException("Error posting account transaction", e)
45   *          .addContextValue("Account Number", accountNumber)
46   *          .addContextValue("Amount Posted", amountPosted)
47   *          .addContextValue("Previous Balance", previousBalance);
48   *   }
49   * }
50   * </pre>
51   * <p>
52   * or improve diagnose data at a higher level:
53   * </p>
54   * <pre>
55   *   try {
56   *     ...
57   *   } catch (ContextedRuntimeException e) {
58   *     throw e.setContextValue("Transaction Id", transactionId);
59   *   } catch (Exception e) {
60   *     if (e instanceof ExceptionContext) {
61   *       e.setContextValue("Transaction Id", transactionId);
62   *     }
63   *     throw e;
64   *   }
65   * }
66   * </pre>
67   * <p>
68   * The output in a printStacktrace() (which often is written to a log) would look something like the following:
69   * </p>
70   * <pre>
71   * org.apache.commons.lang3.exception.ContextedRuntimeException: java.lang.Exception: Error posting account transaction
72   *  Exception Context:
73   *  [1:Account Number=null]
74   *  [2:Amount Posted=100.00]
75   *  [3:Previous Balance=-2.17]
76   *  [4:Transaction Id=94ef1d15-d443-46c4-822b-637f26244899]
77   *
78   *  ---------------------------------
79   *  at org.apache.commons.lang3.exception.ContextedRuntimeExceptionTest.testAddValue(ContextedExceptionTest.java:88)
80   *  ..... (rest of trace)
81   * </pre>
82   *
83   * @see ContextedException
84   * @since 3.0
85   */
86  public class ContextedRuntimeException extends RuntimeException implements ExceptionContext {
87  
88      /** The serialization version. */
89      private static final long serialVersionUID = 20110706L;
90      /** The context where the data is stored. */
91      private final ExceptionContext exceptionContext;
92  
93      /**
94       * Instantiates ContextedRuntimeException without message or cause.
95       * <p>
96       * The context information is stored using a default implementation.
97       */
98      public ContextedRuntimeException() {
99          exceptionContext = new DefaultExceptionContext();
100     }
101 
102     /**
103      * Instantiates ContextedRuntimeException with message, but without cause.
104      * <p>
105      * The context information is stored using a default implementation.
106      *
107      * @param message  the exception message, may be null
108      */
109     public ContextedRuntimeException(final String message) {
110         super(message);
111         exceptionContext = new DefaultExceptionContext();
112     }
113 
114     /**
115      * Instantiates ContextedRuntimeException with cause and message.
116      * <p>
117      * The context information is stored using a default implementation.
118      *
119      * @param message  the exception message, may be null
120      * @param cause  the underlying cause of the exception, may be null
121      */
122     public ContextedRuntimeException(final String message, final Throwable cause) {
123         super(message, cause);
124         exceptionContext = new DefaultExceptionContext();
125     }
126 
127     /**
128      * Instantiates ContextedRuntimeException with cause, message, and ExceptionContext.
129      *
130      * @param message  the exception message, may be null
131      * @param cause  the underlying cause of the exception, may be null
132      * @param context  the context used to store the additional information, null uses default implementation
133      */
134     public ContextedRuntimeException(final String message, final Throwable cause, ExceptionContext context) {
135         super(message, cause);
136         if (context == null) {
137             context = new DefaultExceptionContext();
138         }
139         exceptionContext = context;
140     }
141 
142     /**
143      * Instantiates ContextedRuntimeException with cause, but without message.
144      * <p>
145      * The context information is stored using a default implementation.
146      *
147      * @param cause  the underlying cause of the exception, may be null
148      */
149     public ContextedRuntimeException(final Throwable cause) {
150         super(cause);
151         exceptionContext = new DefaultExceptionContext();
152     }
153 
154     /**
155      * Adds information helpful to a developer in diagnosing and correcting the problem.
156      * For the information to be meaningful, the value passed should have a reasonable
157      * toString() implementation.
158      * Different values can be added with the same label multiple times.
159      * <p>
160      * Note: This exception is only serializable if the object added is serializable.
161      * </p>
162      *
163      * @param label  a textual label associated with information, {@code null} not recommended
164      * @param value  information needed to understand exception, may be {@code null}
165      * @return {@code this}, for method chaining, not {@code null}
166      */
167     @Override
168     public ContextedRuntimeException addContextValue(final String label, final Object value) {
169         exceptionContext.addContextValue(label, value);
170         return this;
171     }
172 
173     /**
174      * {@inheritDoc}
175      */
176     @Override
177     public List<Pair<String, Object>> getContextEntries() {
178         return this.exceptionContext.getContextEntries();
179     }
180 
181     /**
182      * {@inheritDoc}
183      */
184     @Override
185     public Set<String> getContextLabels() {
186         return exceptionContext.getContextLabels();
187     }
188 
189     /**
190      * {@inheritDoc}
191      */
192     @Override
193     public List<Object> getContextValues(final String label) {
194         return this.exceptionContext.getContextValues(label);
195     }
196 
197     /**
198      * {@inheritDoc}
199      */
200     @Override
201     public Object getFirstContextValue(final String label) {
202         return this.exceptionContext.getFirstContextValue(label);
203     }
204 
205     /**
206      * {@inheritDoc}
207      */
208     @Override
209     public String getFormattedExceptionMessage(final String baseMessage) {
210         return exceptionContext.getFormattedExceptionMessage(baseMessage);
211     }
212 
213     /**
214      * Provides the message explaining the exception, including the contextual data.
215      *
216      * @see Throwable#getMessage()
217      * @return the message, never null
218      */
219     @Override
220     public String getMessage() {
221         return getFormattedExceptionMessage(super.getMessage());
222     }
223 
224     /**
225      * Provides the message explaining the exception without the contextual data.
226      *
227      * @see Throwable#getMessage()
228      * @return the message
229      * @since 3.0.1
230      */
231     public String getRawMessage() {
232         return super.getMessage();
233     }
234 
235     /**
236      * Sets information helpful to a developer in diagnosing and correcting the problem.
237      * For the information to be meaningful, the value passed should have a reasonable
238      * toString() implementation.
239      * Any existing values with the same labels are removed before the new one is added.
240      * <p>
241      * Note: This exception is only serializable if the object added as value is serializable.
242      * </p>
243      *
244      * @param label  a textual label associated with information, {@code null} not recommended
245      * @param value  information needed to understand exception, may be {@code null}
246      * @return {@code this}, for method chaining, not {@code null}
247      */
248     @Override
249     public ContextedRuntimeException setContextValue(final String label, final Object value) {
250         exceptionContext.setContextValue(label, value);
251         return this;
252     }
253 
254 }