    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.lang3;
    018
    019import java.util.Objects;
    020
    021/**
    022 * Operations regarding the classpath.
    023 *
    024 * <p>
    025 * The methods of this class do not allow {@code null} inputs.
    026 * </p>
    027 *
    028 * @since 3.3
    029 */
    030//@Immutable
    031public class ClassPathUtils {
    032
    033    /**
    034     * Converts a package name to a Java path ('/').
    035     *
    036     * @param path the source path.
    037     * @return a package name.
    038     * @throws NullPointerException if {@code path} is null.
    039     * @since 3.13.0
    040     */
    041    public static String packageToPath(final String path) {
    042        return Objects.requireNonNull(path, "path").replace('.', '/');
    043    }
    044
    045    /**
    046     * Converts a Java path ('/') to a package name.
    047     *
    048     * @param path the source path.
    049     * @return a package name.
    050     * @throws NullPointerException if {@code path} is null.
    051     * @since 3.13.0
    052     */
    053    public static String pathToPackage(final String path) {
    054        return Objects.requireNonNull(path, "path").replace('/', '.');
    055    }
    056
    057    /**
    058     * Returns the fully qualified name for the resource with name {@code resourceName} relative to the given context.
    059     *
    060     * <p>
    061     * Note that this method does not check whether the resource actually exists. It only constructs the name. Null inputs are not allowed.
    062     * </p>
    063     *
    064     * <pre>
    065     * ClassPathUtils.toFullyQualifiedName(StringUtils.class, "StringUtils.properties") = "org.apache.commons.lang3.StringUtils.properties"
    066     * </pre>
    067     *
    068     * @param context      The context for constructing the name.
    069     * @param resourceName the resource name to construct the fully qualified name for.
    070     * @return the fully qualified name of the resource with name {@code resourceName}.
    071     * @throws NullPointerException if either {@code context} or {@code resourceName} is null.
    072     */
    073    public static String toFullyQualifiedName(final Class<?> context, final String resourceName) {
    074        Objects.requireNonNull(context, "context");
    075        Objects.requireNonNull(resourceName, "resourceName");
    076        return toFullyQualifiedName(context.getPackage(), resourceName);
    077    }
    078
    079    /**
    080     * Returns the fully qualified name for the resource with name {@code resourceName} relative to the given context.
    081     *
    082     * <p>
    083     * Note that this method does not check whether the resource actually exists. It only constructs the name. Null inputs are not allowed.
    084     * </p>
    085     *
    086     * <pre>
    087     * ClassPathUtils.toFullyQualifiedName(StringUtils.class.getPackage(), "StringUtils.properties") = "org.apache.commons.lang3.StringUtils.properties"
    088     * </pre>
    089     *
    090     * @param context      The context for constructing the name.
    091     * @param resourceName the resource name to construct the fully qualified name for.
    092     * @return the fully qualified name of the resource with name {@code resourceName}.
    093     * @throws NullPointerException if either {@code context} or {@code resourceName} is null.
    094     */
    095    public static String toFullyQualifiedName(final Package context, final String resourceName) {
    096        Objects.requireNonNull(context, "context");
    097        Objects.requireNonNull(resourceName, "resourceName");
    098        return context.getName() + "." + resourceName;
    099    }
    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    public ClassPathUtils() {
    154    }
    155
    156}