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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;
18  
19  import java.util.Objects;
20  
21  /**
22   * Operations regarding the classpath.
23   *
24   * <p>
25   * The methods of this class do not allow {@code null} inputs.
26   * </p>
27   *
28   * @since 3.3
29   */
30  //@Immutable
31  public class ClassPathUtils {
32  
33      /**
34       * Converts a package name to a Java path ('/').
35       *
36       * @param path the source path.
37       * @return a package name.
38       * @throws NullPointerException if {@code path} is null.
39       * @since 3.13.0
40       */
41      public static String packageToPath(final String path) {
42          return Objects.requireNonNull(path, "path").replace('.', '/');
43      }
44  
45      /**
46       * Converts a Java path ('/') to a package name.
47       *
48       * @param path the source path.
49       * @return a package name.
50       * @throws NullPointerException if {@code path} is null.
51       * @since 3.13.0
52       */
53      public static String pathToPackage(final String path) {
54          return Objects.requireNonNull(path, "path").replace('/', '.');
55      }
56  
57      /**
58       * Returns the fully qualified name for the resource with name {@code resourceName} relative to the given context.
59       *
60       * <p>
61       * Note that this method does not check whether the resource actually exists. It only constructs the name. Null inputs are not allowed.
62       * </p>
63       *
64       * <pre>
65       * ClassPathUtils.toFullyQualifiedName(StringUtils.class, "StringUtils.properties") = "org.apache.commons.lang3.StringUtils.properties"
66       * </pre>
67       *
68       * @param context      The context for constructing the name.
69       * @param resourceName the resource name to construct the fully qualified name for.
70       * @return the fully qualified name of the resource with name {@code resourceName}.
71       * @throws NullPointerException if either {@code context} or {@code resourceName} is null.
72       */
73      public static String toFullyQualifiedName(final Class<?> context, final String resourceName) {
74          Objects.requireNonNull(context, "context");
75          Objects.requireNonNull(resourceName, "resourceName");
76          return toFullyQualifiedName(context.getPackage(), resourceName);
77      }
78  
79      /**
80       * Returns the fully qualified name for the resource with name {@code resourceName} relative to the given context.
81       *
82       * <p>
83       * Note that this method does not check whether the resource actually exists. It only constructs the name. Null inputs are not allowed.
84       * </p>
85       *
86       * <pre>
87       * ClassPathUtils.toFullyQualifiedName(StringUtils.class.getPackage(), "StringUtils.properties") = "org.apache.commons.lang3.StringUtils.properties"
88       * </pre>
89       *
90       * @param context      The context for constructing the name.
91       * @param resourceName the resource name to construct the fully qualified name for.
92       * @return the fully qualified name of the resource with name {@code resourceName}.
93       * @throws NullPointerException if either {@code context} or {@code resourceName} is null.
94       */
95      public static String toFullyQualifiedName(final Package context, final String resourceName) {
96          Objects.requireNonNull(context, "context");
97          Objects.requireNonNull(resourceName, "resourceName");
98          return context.getName() + "." + resourceName;
99      }
100 
101     /**
102      * Returns the fully qualified path for the resource with name {@code resourceName} relative to the given context.
103      *
104      * <p>
105      * Note that this method does not check whether the resource actually exists. It only constructs the path. Null inputs are not allowed.
106      * </p>
107      *
108      * <pre>
109      * ClassPathUtils.toFullyQualifiedPath(StringUtils.class, "StringUtils.properties") = "org/apache/commons/lang3/StringUtils.properties"
110      * </pre>
111      *
112      * @param context      The context for constructing the path.
113      * @param resourceName the resource name to construct the fully qualified path for.
114      * @return the fully qualified path of the resource with name {@code resourceName}.
115      * @throws NullPointerException if either {@code context} or {@code resourceName} is null.
116      */
117     public static String toFullyQualifiedPath(final Class<?> context, final String resourceName) {
118         Objects.requireNonNull(context, "context");
119         Objects.requireNonNull(resourceName, "resourceName");
120         return toFullyQualifiedPath(context.getPackage(), resourceName);
121     }
122 
123     /**
124      * Returns the fully qualified path for the resource with name {@code resourceName} relative to the given context.
125      *
126      * <p>
127      * Note that this method does not check whether the resource actually exists. It only constructs the path. Null inputs are not allowed.
128      * </p>
129      *
130      * <pre>
131      * ClassPathUtils.toFullyQualifiedPath(StringUtils.class.getPackage(), "StringUtils.properties") = "org/apache/commons/lang3/StringUtils.properties"
132      * </pre>
133      *
134      * @param context      The context for constructing the path.
135      * @param resourceName the resource name to construct the fully qualified path for.
136      * @return the fully qualified path of the resource with name {@code resourceName}.
137      * @throws NullPointerException if either {@code context} or {@code resourceName} is null.
138      */
139     public static String toFullyQualifiedPath(final Package context, final String resourceName) {
140         Objects.requireNonNull(context, "context");
141         Objects.requireNonNull(resourceName, "resourceName");
142         return packageToPath(context.getName()) + "/" + resourceName;
143     }
144 
145     /**
146      * {@link ClassPathUtils} instances should NOT be constructed in standard programming. Instead, the class should be used as
147      * {@code ClassPathUtils.toFullyQualifiedName(MyClass.class, "MyClass.properties");}.
148      *
149      * <p>
150      * This constructor is public to permit tools that require a JavaBean instance to operate.
151      * </p>
152      *
153      * @deprecated TODO Make private in 4.0.
154      */
155     @Deprecated
156     public ClassPathUtils() {
157         // empty
158     }
159 
160 }