1 /*
2  * Copyright (C) 2011 Google Inc.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
5  * use this file except in compliance with the License. You may obtain a copy of
6  * the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13  * License for the specific language governing permissions and limitations under
14  * the License.
15  */
16 
17 package com.google.inject.spi;
18 
19 import com.google.inject.Binder;
20 import com.google.inject.Binding;
21 import com.google.inject.Injector;
22 import com.google.inject.internal.util.StackTraceElements;
23 
24 import java.lang.reflect.Member;
25 
26 /**
27  * A combination of a {@link Dependency} and the {@link Binding#getSource()
28  * source} where the dependency was bound.
29  *
30  * @author sameb@google.com (Sam Berlin)
31  * @since 4.0
32  */
33 public final class DependencyAndSource {
34   private final Dependency<?> dependency;
35   private final Object source;
36 
DependencyAndSource(Dependency<?> dependency, Object source)37   public DependencyAndSource(Dependency<?> dependency, Object source) {
38     this.dependency = dependency;
39     this.source = source;
40   }
41 
42   /**
43    * Returns the Dependency, if one exists. For anything that can be referenced
44    * by {@link Injector#getBinding}, a dependency exists. A dependency will not
45    * exist (and this will return null) for types initialized with
46    * {@link Binder#requestInjection} or {@link Injector#injectMembers(Object)},
47    * nor will it exist for objects injected into Providers bound with
48    * LinkedBindingBuilder#toProvider(Provider).
49    */
getDependency()50   public Dependency<?> getDependency() {
51     return dependency;
52   }
53 
54   /**
55    * Returns a string describing where this dependency was bound. If the binding
56    * was just-in-time, there is no valid binding source, so this describes the
57    * class in question.
58    */
getBindingSource()59   public String getBindingSource() {
60     if (source instanceof Class) {
61       return StackTraceElements.forType((Class) source).toString();
62     } else if (source instanceof Member) {
63       return StackTraceElements.forMember((Member) source).toString();
64     } else {
65       return source.toString();
66     }
67   }
68 
69   @Override
toString()70   public String toString() {
71     Dependency<?> dep = getDependency();
72     Object source = getBindingSource();
73     if (dep != null) {
74       return "Dependency: " + dep + ", source: " + source;
75     } else {
76       return "Source: " + source;
77     }
78   }
79 }