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;
21
22 import org.apache.commons.lang3.builder.EqualsBuilder;
23 import org.apache.commons.lang3.builder.HashCodeBuilder;
24 import org.grouplens.grapht.reflect.Satisfaction;
25 import org.grouplens.grapht.util.Preconditions;
26
27 import java.io.Serializable;
28
29 /**
30 * A component to be instantiated in the final dependency plan. A component consists of a {@link
31 * Satisfaction} and related information for instantiating it (such as the {@link CachePolicy}).
32 *
33 * @author <a href="http://grouplens.org">GroupLens Research</a>
34 */
35 public class Component implements Serializable {
36 private static final long serialVersionUID = 5L;
37
38 private final Satisfaction satisfaction;
39 private final CachePolicy cachePolicy;
40
41 private Component(Satisfaction satisfaction, CachePolicy policy) {
42 Preconditions.notNull("satisfaction", satisfaction);
43 Preconditions.notNull("policy", policy);
44
45 this.satisfaction = satisfaction;
46 cachePolicy = policy;
47 }
48
49 /**
50 * Create a new Component wrapping the given satisfaction and cache policy. The injector is
51 * responsible for using the satisfaction to implement this component consistent with its
52 * cache policy.
53 *
54 * @param satisfaction The satisfaction to wrap
55 * @param policy The policy used with this satisfaction
56 * @throws NullPointerException the satisfaction or policy is null
57 */
58 public static Component create(Satisfaction satisfaction, CachePolicy policy) {
59 return new Component(satisfaction, policy);
60 }
61
62 /**
63 * @return The Satisfaction stored in this pair
64 */
65 public Satisfaction getSatisfaction() {
66 return satisfaction;
67 }
68
69 /**
70 * @return The CachePolicy that must be implemented on top of the providers
71 * from this {@link #getSatisfaction() satisfaction}
72 */
73 public CachePolicy getCachePolicy() {
74 return cachePolicy;
75 }
76
77 @Override
78 public boolean equals(Object o) {
79 if (!(o instanceof Component)) {
80 return false;
81 }
82
83 Component c = (Component) o;
84 EqualsBuilder eqb = new EqualsBuilder();
85 return eqb.append(satisfaction, c.satisfaction)
86 .append(cachePolicy, c.cachePolicy)
87 .isEquals();
88 }
89
90 @Override
91 public int hashCode() {
92 HashCodeBuilder hcb = new HashCodeBuilder();
93 return hcb.append(satisfaction)
94 .append(cachePolicy)
95 .toHashCode();
96 }
97
98 @Override
99 public String toString() {
100 return "(" + satisfaction + ", " + cachePolicy + ")";
101 }
102 }