1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one *
3 * or more contributor license agreements. See the NOTICE file *
4 * distributed with this work for additional information *
5 * regarding copyright ownership. The ASF licenses this file *
6 * to you under the Apache License, Version 2.0 (the *
7 * "License"); you may not use this file except in compliance *
8 * with the License. You may obtain a copy of the License at *
9 * *
10 * http://www.apache.org/licenses/LICENSE-2.0 *
11 * *
12 * Unless required by applicable law or agreed to in writing, *
13 * software distributed under the License is distributed on an *
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
15 * KIND, either express or implied. See the License for the *
16 * specific language governing permissions and limitations *
17 * under the License. *
18 */
19 package org.apache.rat.configuration.builders;
20
21 import java.util.Map;
22
23 import org.apache.rat.ConfigurationException;
24 import org.apache.rat.analysis.IHeaderMatcher;
25 import org.apache.rat.analysis.IHeaders;
26 import org.apache.rat.config.parameters.ComponentType;
27 import org.apache.rat.config.parameters.ConfigComponent;
28
29 /**
30 * A reference matching Matcher builder.
31 * <p>
32 * This class stores a matcher id as a reference to the matcher. It also has a
33 * map of matcher ids to the matcher instances. When {@code build()} is called the matcher
34 * reference is looked up in the map. If it is found then its value is returned
35 * from the {@code build()} call. If the reference is not located then a
36 * IHeaderMatcherProxy is returned. the IHeaderMatcherProxy is resolved in a
37 * later configuration construction phase.
38 */
39 public class MatcherRefBuilder extends AbstractBuilder {
40 private String referenceId;
41 private Map<String, IHeaderMatcher> matchers;
42
43 /** the reference id attribute */
44 public static final String ATT_REF_ID = "refId";
45
46 /**
47 * Constructs the MatcherReferenceBuilder using the provided reference id.
48 *
49 * @param refId the reverence to the matcher id.
50 * @return this builder for chaining.
51 */
52 public MatcherRefBuilder setRefId(String refId) {
53 this.referenceId = refId;
54 return this;
55 }
56
57 @Override
58 public Class<?> builtClass() {
59 return IHeaderMatcherProxy.class;
60 }
61
62 /**
63 * Set the Map of matcher ids to matcher instances.
64 *
65 * @param matchers the Map of ids to instances.
66 * @return this builder for chaining.
67 */
68 public MatcherRefBuilder setMatcherMap(Map<String, IHeaderMatcher> matchers) {
69 this.matchers = matchers;
70 return this;
71 }
72
73 @Override
74 public IHeaderMatcher build() {
75 if (matchers == null) {
76 throw new ConfigurationException("'matchers' not set");
77 }
78 IHeaderMatcher result = matchers.get(referenceId);
79 return result != null ? result : new IHeaderMatcherProxy(referenceId, matchers);
80 }
81
82 @Override
83 public String toString() {
84 return "MathcerRefBuilder: " + referenceId;
85 }
86
87 /**
88 * A class that is a proxy to the actual matcher. It retrieves the actual
89 * matcher from the map of matcher ids to matcher instances on the first use of
90 * the matcher. This allows earlier read matchers to reference later constructed
91 * matchers as long as all the matchers are constructed before the earlier one
92 * is used.
93 */
94 @ConfigComponent(type = ComponentType.MATCHER, name = "matcherRef", desc = "A pointer to another Matcher")
95 public static class IHeaderMatcherProxy implements IHeaderMatcher {
96
97 @ConfigComponent(type = ComponentType.PARAMETER, name = "refId", desc = "Reference to an existing matcher")
98 private final String proxyId;
99 private IHeaderMatcher wrapped;
100
101 @ConfigComponent(type = ComponentType.BUILD_PARAMETER, name = "matcherMap", desc = "Map of matcher names to matcher instances")
102 private Map<String, IHeaderMatcher> matchers;
103
104 /**
105 * Constuctor. The matchers map should be a reference to an object that will be
106 * updated by later processing of matcher definitions.
107 *
108 * @param proxyId the id of the matcher to find.
109 * @param matchers a mapping of matchers that have been found.
110 */
111 public IHeaderMatcherProxy(String proxyId, Map<String, IHeaderMatcher> matchers) {
112 this.proxyId = proxyId;
113 this.matchers = matchers;
114 }
115
116 /**
117 * Get the reference ID that this proxy is using.
118 *
119 * @return the reference id that points to the actual matcher.
120 */
121 public String getRefId() {
122 return proxyId;
123 }
124
125 private void checkProxy() {
126 if (wrapped == null) {
127 wrapped = matchers.get(proxyId);
128 if (wrapped == null) {
129 throw new IllegalStateException(String.format("%s is not a valid matcher id", proxyId));
130 }
131 matchers = null;
132 }
133 }
134
135 @Override
136 public String getId() {
137 checkProxy();
138 return wrapped.getId();
139 }
140
141 @Override
142 public void reset() {
143 checkProxy();
144 wrapped.reset();
145 }
146
147 @Override
148 public boolean matches(IHeaders header) {
149 checkProxy();
150 return wrapped.matches(header);
151 }
152 }
153
154 }