Java tutorial
/* * Copyright 2013-present Facebook, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. You may obtain * a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package com.facebook.buck.rules; import com.google.common.collect.ImmutableSetMultimap; import java.util.Set; public class Classpaths { private Classpaths() { // Utility class } /** * Include the classpath entries from all JavaLibraryRules that have a direct line of lineage * to this rule through other JavaLibraryRules. For example, in the following dependency graph: * * A * / \ * B C * / \ / \ * D E F G * * If all of the nodes correspond to BuildRules that implement JavaLibraryRule except for * B (suppose B is a Genrule), then A's classpath will include C, F, and G, but not D and E. * This is because D and E are used to generate B, but do not contribute .class files to things * that depend on B. However, if C depended on E as well as F and G, then E would be included in * A's classpath. */ public static ImmutableSetMultimap<BuildRule, String> getClasspathEntries(Set<BuildRule> deps) { final ImmutableSetMultimap.Builder<BuildRule, String> classpathEntries = ImmutableSetMultimap.builder(); for (BuildRule dep : deps) { if (dep instanceof JavaLibraryRule) { JavaLibraryRule libraryRule = (JavaLibraryRule) dep; classpathEntries.putAll(libraryRule.getTransitiveClasspathEntries()); } } return classpathEntries.build(); } }