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1   /*
2    * Grapht, an open source dependency injector.
3    * Copyright 2014-2015 various contributors (see CONTRIBUTORS.txt)
4    * Copyright 2010-2014 Regents of the University of Minnesota
5    *
6    * This program is free software; you can redistribute it and/or modify
7    * it under the terms of the GNU Lesser General Public License as
8    * published by the Free Software Foundation; either version 2.1 of the
9    * License, or (at your option) any later version.
10   *
11   * This program is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13   * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
14   * details.
15   *
16   * You should have received a copy of the GNU General Public License along with
17   * this program; if not, write to the Free Software Foundation, Inc., 51
18   * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19   */
20  package org.grouplens.grapht.solver;
21  
22  import org.apache.commons.lang3.tuple.Pair;
23  import org.grouplens.grapht.ResolutionException;
24  import org.grouplens.grapht.reflect.Desire;
25  import org.grouplens.grapht.reflect.InjectionPoint;
26  import org.grouplens.grapht.reflect.Satisfaction;
27  
28  import java.util.List;
29  
30  /**
31   * Thrown when a desire cannot be resolved to an instantiable satisfaction.
32   * 
33   * @author <a href="http://grouplens.org">GroupLens Research</a>
34   */
35  public class UnresolvableDependencyException extends ResolutionException {
36      private static final long serialVersionUID = 1L;
37  
38      private final DesireChain desires;
39      private final InjectionContext context;
40      
41      public UnresolvableDependencyException(DesireChain chain, InjectionContext context) {
42          this.desires = chain;
43          this.context = context;
44      }
45  
46      public UnresolvableDependencyException(DesireChain chain, InjectionContext context, Throwable cause) {
47          super(cause);
48          this.desires = chain;
49          this.context = context;
50      }
51      
52      /**
53       * Get the context for this error.
54       *
55       * @return The context that produced the unresolvable desire
56       */
57      public InjectionContext getContext() {
58          return context;
59      }
60  
61      /**
62       * Get the entire desire chain in which resolution failed.
63       * @return The desire chain that failed to resolve.
64       */
65      public DesireChain getDesireChain() {
66          return desires;
67      }
68      
69      /**
70       * Get the desire that failed to resolve.
71       *
72       * @return The unresolvable desire
73       */
74      public Desire getDesire() {
75          return desires.getCurrentDesire();
76      }
77      
78      @Override
79      public String getMessage() {
80          StringBuilder sb = new StringBuilder("Unable to satisfy desire ")
81                  .append(format(desires.getCurrentDesire().getInjectionPoint()));
82          List<Pair<Satisfaction, InjectionPoint>> path = context;
83          if (!path.isEmpty()) {
84              sb.append(" of ")
85                .append(path.get(0).getLeft());
86          }
87          sb.append('\n')
88            .append(format(context, desires));
89          return sb.toString();
90      }
91  }