Java tutorial
/* * Copyright 2017-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.android; import com.facebook.buck.core.build.buildable.context.BuildableContext; import com.facebook.buck.core.build.context.BuildContext; import com.facebook.buck.core.build.execution.context.ExecutionContext; import com.facebook.buck.core.model.BuildTarget; import com.facebook.buck.core.model.impl.BuildTargetPaths; import com.facebook.buck.core.rulekey.AddToRuleKey; import com.facebook.buck.core.rules.BuildRule; import com.facebook.buck.core.rules.SourcePathRuleFinder; import com.facebook.buck.core.rules.common.BuildableSupport; import com.facebook.buck.core.rules.impl.AbstractBuildRule; import com.facebook.buck.core.sourcepath.ExplicitBuildTargetSourcePath; import com.facebook.buck.core.sourcepath.SourcePath; import com.facebook.buck.io.BuildCellRelativePath; import com.facebook.buck.io.filesystem.ProjectFilesystem; import com.facebook.buck.step.AbstractExecutionStep; import com.facebook.buck.step.Step; import com.facebook.buck.step.StepExecutionResult; import com.facebook.buck.step.StepExecutionResults; import com.facebook.buck.step.fs.MakeCleanDirectoryStep; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableSortedSet; import com.google.common.collect.Ordering; import java.io.IOException; import java.nio.file.Path; import java.util.SortedSet; import javax.annotation.Nullable; /** * Copy filtered string resources (values/strings.xml) files to output directory. These will be used * by i18n to map resource_id to fbt_hash with resource_name as the intermediary */ public class GenerateStringResources extends AbstractBuildRule { @AddToRuleKey private final ImmutableList<SourcePath> filteredResources; private final ImmutableList<FilteredResourcesProvider> filteredResourcesProviders; private final SourcePathRuleFinder ruleFinder; private static final String VALUES = "values"; private static final String STRINGS_XML = "strings.xml"; private static final String NEW_RES_DIR_FORMAT = "%04x"; // "4 digit hex" => 65536 files // we currently have around 1000 "values/strings.xml" files in fb4a protected GenerateStringResources(BuildTarget buildTarget, ProjectFilesystem projectFilesystem, SourcePathRuleFinder ruleFinder, ImmutableList<FilteredResourcesProvider> filteredResourcesProviders) { super(buildTarget, projectFilesystem); this.ruleFinder = ruleFinder; this.filteredResourcesProviders = filteredResourcesProviders; this.filteredResources = filteredResourcesProviders.stream() .flatMap(provider -> provider.getResDirectories().stream()) .collect(ImmutableList.toImmutableList()); } @Override public SortedSet<BuildRule> getBuildDeps() { return BuildableSupport.deriveDeps(this, ruleFinder) .collect(ImmutableSortedSet.toImmutableSortedSet(Ordering.natural())); } @Override public ImmutableList<? extends Step> getBuildSteps(BuildContext buildContext, BuildableContext buildableContext) { ImmutableList.Builder<Step> steps = ImmutableList.builder(); // Make sure we have a clean output directory Path outputDirPath = getPathForStringResourcesDirectory(); steps.addAll(MakeCleanDirectoryStep.of(BuildCellRelativePath .fromCellRelativePath(buildContext.getBuildCellRootPath(), getProjectFilesystem(), outputDirPath))); // Copy `values/strings.xml` files from resource directories to hex-enumerated resource // directories under output directory, retaining the input order steps.add(new AbstractExecutionStep("copy_string_resources") { @Override public StepExecutionResult execute(ExecutionContext context) throws IOException { ProjectFilesystem fileSystem = getProjectFilesystem(); int i = 0; for (Path resDir : filteredResourcesProviders.stream() .flatMap(provider -> provider .getRelativeResDirectories(fileSystem, buildContext.getSourcePathResolver()) .stream()) .collect(ImmutableList.toImmutableList())) { Path stringsFilePath = resDir.resolve(VALUES).resolve(STRINGS_XML); if (fileSystem.exists(stringsFilePath)) { // create <output_dir>/<new_res_dir>/values Path newStringsFileDir = outputDirPath.resolve(String.format(NEW_RES_DIR_FORMAT, i++)) .resolve(VALUES); fileSystem.mkdirs(newStringsFileDir); // copy <res_dir>/values/strings.xml -> // <output_dir>/<new_res_dir>/values/strings.xml fileSystem.copyFile(stringsFilePath, newStringsFileDir.resolve(STRINGS_XML)); } } return StepExecutionResults.SUCCESS; } }); // Cache the outputDirPath with all the required string resources buildableContext.recordArtifact(outputDirPath); return steps.build(); } private Path getPathForStringResourcesDirectory() { return BuildTargetPaths.getScratchPath(getProjectFilesystem(), getBuildTarget(), "__%s__"); } @Nullable @Override public SourcePath getSourcePathToOutput() { return ExplicitBuildTargetSourcePath.of(getBuildTarget(), getPathForStringResourcesDirectory()); } }