Source code

001/*
002 * JDrupes Builder
003 * Copyright (C) 2025 Michael N. Lipp
004 * 
005 * This program is free software: you can redistribute it and/or modify
006 * it under the terms of the GNU Affero General Public License as
007 * published by the Free Software Foundation, either version 3 of the
008 * License, or (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
013 * GNU Affero General Public License for more details.
014 *
015 * You should have received a copy of the GNU Affero General Public License
016 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
017 */
018
019package org.jdrupes.builder.uberjar;
020
021import com.google.common.flogger.FluentLogger;
022import io.github.azagniotov.matcher.AntPathMatcher;
023import java.io.IOException;
024import java.nio.file.Path;
025import java.util.ArrayList;
026import java.util.Arrays;
027import java.util.List;
028import java.util.Map;
029import java.util.Objects;
030import java.util.concurrent.ConcurrentHashMap;
031import java.util.function.Predicate;
032import java.util.jar.JarEntry;
033import java.util.stream.Stream;
034import org.jdrupes.builder.api.BuildException;
035import org.jdrupes.builder.api.ConfigurationException;
036import org.jdrupes.builder.api.FileTree;
037import org.jdrupes.builder.api.Generator;
038import org.jdrupes.builder.api.IOResource;
039import org.jdrupes.builder.api.Intent;
040import static org.jdrupes.builder.api.Intent.*;
041import org.jdrupes.builder.api.Project;
042import org.jdrupes.builder.api.Resource;
043import org.jdrupes.builder.api.ResourceRequest;
044import org.jdrupes.builder.api.ResourceType;
045import static org.jdrupes.builder.api.ResourceType.*;
046import org.jdrupes.builder.api.Resources;
047import org.jdrupes.builder.java.AppJarFile;
048import org.jdrupes.builder.java.ClassTree;
049import org.jdrupes.builder.java.ClasspathElement;
050import org.jdrupes.builder.java.JarFile;
051import org.jdrupes.builder.java.JarFileEntry;
052import org.jdrupes.builder.java.JavaResourceTree;
053import static org.jdrupes.builder.java.JavaTypes.*;
054import org.jdrupes.builder.java.LibraryBuilder;
055import org.jdrupes.builder.java.LibraryJarFile;
056import org.jdrupes.builder.java.ServicesEntryResource;
057import org.jdrupes.builder.mvnrepo.MvnRepoJarFile;
058import org.jdrupes.builder.mvnrepo.MvnRepoLookup;
059import org.jdrupes.builder.mvnrepo.MvnRepoResource;
060import static org.jdrupes.builder.mvnrepo.MvnRepoTypes.*;
061
062/// A [Generator] for uber jars.
063///
064/// Depending on the request, the generator provides two types of resources.
065/// 
066/// 1. A [JarFile]. This type of resource is also returned if a more
067///    general [ResourceType] such as [ClasspathElement] is requested.
068///
069/// 2. An [AppJarFile]. When requesting this special jar type, the
070///    generator checks if a main class is specified.
071///
072/// The generator takes the following approach:
073/// 
074///   * Request `Resources<ClasspathElement>` from the providers. Add the
075///     resource trees and the jar files to the sources to be processed.
076///     Ignore jar files from maven repositories (instances of
077///     [MvnRepoJarFile]).
078///   * Request all [MvnRepoResource]s from the providers and use them for
079///     a dependency resolution. Add the jar files from the dependency
080///     resolution to the resources to be processed.
081///   * Add resources from the sources to the uber jar. Merge the files in
082///     `META-INF/services/` that have the same name by concatenating them.
083///   * Filter out any other duplicate direct child files of `META-INF`.
084///     These files often contain information related to the origin jar
085///     that is not applicable to the uber jar.
086///   * Filter out any module-info.class entries.
087///
088/// Note that the [UberJarBuilder] does deliberately not request the
089/// [ClasspathElement]s as `RuntimeResources` because this may return
090/// resources twice if a project uses another project as runtime
091/// dependency (i.e. with [Intent#Consume]. If this rule causes entries
092/// to be missing, simply add them explicitly.  
093/// 
094/// The resource type of the uber jar generator's output is one
095/// of the resource types of its inputs, because uber jars can also be used
096/// as [ClasspathElement]. Therefore, if you want to create an uber jar
097/// from all resources provided by a project, you must not add the
098/// generator to the project like this:
099/// ```java
100///     generator(UberJarGenerator::new).add(this); // Circular dependency
101/// ```
102///
103/// This would add the project as provider and thus make the uber jar
104/// generator as supplier to the project its own provider (via
105/// [Project.resources][Project#resources]). Rather, you have to use this
106/// slightly more complicated approach to adding providers to the uber
107/// jar generator:
108/// ```java
109///     generator(UberJarGenerator::new)
110///         .addAll(providers().select(Forward, Expose, Supply));
111/// ```
112/// This requests the same providers from the project as 
113/// [Project.resources][Project#resources] does, but allows the uber jar
114/// generator's [addFrom] method to filter out the uber jar
115/// generator itself from the providers. The given intents can
116/// vary depending on the requirements.
117///
118/// If you don't want the generated uber jar to be available to other
119/// generators of your project, you can also add it to a project like this:
120/// ```java
121///     dependency(new UberJarGenerator(this)
122///         .from(providers(EnumSet.of(Forward, Expose, Supply))), Intent.Forward)
123/// ```
124///
125/// Of course, the easiest thing to do is separate the generation of
126/// class trees or library jars from the generation of the uber jar by
127/// generating the uber jar in a project of its own. Often the root
128/// project can be used for this purpose.  
129///
130public class UberJarBuilder extends LibraryBuilder {
131
132    private static final FluentLogger logger = FluentLogger.forEnclosingClass();
133    @SuppressWarnings("PMD.FieldNamingConventions")
134    private static final AntPathMatcher pathMatcher
135        = new AntPathMatcher.Builder().build();
136    private Map<Path, java.util.jar.JarFile> openJars = Map.of();
137    private Predicate<Resource> resourceFilter = _ -> true;
138    private final List<String> ignoredDuplicates = new ArrayList<>();
139
140    /// Instantiates a new uber jar generator.
141    ///
142    /// @param project the project
143    ///
144    public UberJarBuilder(Project project) {
145        super(Objects.requireNonNull(project));
146    }
147
148    @Override
149    public UberJarBuilder name(String name) {
150        rename(Objects.requireNonNull(name));
151        return this;
152    }
153
154    /// Ignore duplicates matching the given glob patterns when merging.
155    ///
156    /// @param patterns the patterns
157    /// @return the uber jar builder
158    ///
159    public UberJarBuilder ignoreDuplicates(String... patterns) {
160        ignoredDuplicates.addAll(Arrays.asList(patterns));
161        return this;
162    }
163
164    @Override
165    protected void collectFromProviders(
166            Map<Path, Resources<IOResource>> contents) {
167        openJars = new ConcurrentHashMap<>();
168        contentProviders().stream().filter(p -> !p.equals(this))
169            .map(p -> p.resources(
170                of(ClasspathElementType).using(Supply, Expose)))
171            .flatMap(s -> s).parallel()
172            .filter(resourceFilter::test).forEach(cpe -> {
173                if (cpe instanceof FileTree<?> fileTree) {
174                    collect(contents, fileTree);
175                } else if (cpe instanceof JarFile jarFile
176                    // Ignore jar files from maven repositories, see below
177                    && !(jarFile instanceof MvnRepoJarFile)) {
178                    addJarFile(contents, jarFile, openJars);
179                }
180            });
181
182        // Jar files from maven repositories must be resolved before
183        // they can be added to the uber jar, i.e. they must be added
184        // with their transitive dependencies.
185        var lookup = new MvnRepoLookup();
186        lookup.resolve(contentProviders().stream().map(
187            p -> p.resources(of(MvnRepoDependencyType).usingAll()))
188            .flatMap(s -> s));
189        project().context().resources(lookup, of(ClasspathElementType)
190            .using(Consume, Reveal, Supply, Expose, Forward))
191            .parallel().filter(resourceFilter::test).forEach(cpe -> {
192                if (cpe instanceof MvnRepoJarFile jarFile) {
193                    addJarFile(contents, jarFile, openJars);
194                }
195            });
196    }
197
198    /// Apply the given filter to the resources obtained from the provider.
199    /// The resources can be [ClasspathElement]s or [MvnRepoResource]s.
200    /// This may be required to avoid warnings about duplicates if e.g.
201    /// a sub-project provides generated resources both as
202    /// [ClassTree]/[JavaResourceTree] and as [LibraryJarFile].
203    ///
204    /// @param filter the filter. Returns `true` for resources to be
205    /// included.
206    /// @return the uber jar generator
207    ///
208    public UberJarBuilder resourceFilter(Predicate<Resource> filter) {
209        resourceFilter = Objects.requireNonNull(filter);
210        return this;
211    }
212
213    private void addJarFile(Map<Path, Resources<IOResource>> entries,
214            JarFile jarFile, Map<Path, java.util.jar.JarFile> openJars) {
215        @SuppressWarnings({ "PMD.CloseResource" })
216        java.util.jar.JarFile jar
217            = openJars.computeIfAbsent(jarFile.path(), _ -> {
218                try {
219                    return new java.util.jar.JarFile(jarFile.path().toFile());
220                } catch (IOException e) {
221                    throw new BuildException().from(this).cause(e);
222                }
223            });
224        jar.stream().filter(Predicate.not(JarEntry::isDirectory))
225            .filter(e -> !Path.of(e.getName())
226                .endsWith(Path.of("module-info.class")))
227            .filter(e -> {
228                // Filter top-level entries in META-INF/
229                var segs = Path.of(e.getRealName()).iterator();
230                if (segs.next().equals(Path.of("META-INF"))) {
231                    segs.next();
232                    return segs.hasNext();
233                }
234                return true;
235            }).forEach(e -> {
236                var relPath = Path.of(e.getRealName());
237                entries.computeIfAbsent(relPath,
238                    _ -> Resources.with(IOResource.class))
239                    .add(new JarFileEntry(jar, e));
240            });
241    }
242
243    @SuppressWarnings({ "PMD.UselessPureMethodCall",
244        "PMD.AvoidLiteralsInIfCondition" })
245    @Override
246    protected void resolveDuplicates(Map<Path, Resources<IOResource>> entries) {
247        entries.entrySet().parallelStream().forEach(item -> {
248            var entryName = item.getKey();
249            var candidates = item.getValue();
250            if (candidates.stream().count() == 1) {
251                return;
252            }
253            if (entryName.startsWith("META-INF/services")) {
254                var combined = new ServicesEntryResource();
255                candidates.stream().forEach(service -> {
256                    try {
257                        combined.add(service);
258                    } catch (IOException e) {
259                        throw new BuildException().from(this).cause(e);
260                    }
261                });
262                candidates.clear();
263                candidates.add(combined);
264                return;
265            }
266            if (entryName.startsWith("META-INF")) {
267                candidates.clear();
268            }
269            if (ignoredDuplicates.stream()
270                .map(p -> pathMatcher.isMatch(p, entryName.toString()))
271                .filter(Boolean::booleanValue).findFirst().isPresent()) {
272                return;
273            }
274            candidates.stream().reduce((a, b) -> {
275                logger.atWarning().log("Entry %s from %s duplicates"
276                    + " entry from %s and is skipped.", entryName, a, b);
277                return a;
278            });
279        });
280    }
281
282    @Override
283    @SuppressWarnings({ "PMD.CollapsibleIfStatements", "unchecked",
284        "PMD.CloseResource", "PMD.UseTryWithResources",
285        "PMD.CognitiveComplexity", "PMD.CyclomaticComplexity" })
286    protected <T extends Resource> Stream<T>
287            doProvide(ResourceRequest<T> request) {
288        if (!request.accepts(AppJarFileType)
289            && !request.accepts(CleanlinessType)) {
290            return Stream.empty();
291        }
292
293        // Maybe only delete
294        if (request.accepts(CleanlinessType)) {
295            destination().resolve(jarName()).toFile().delete();
296            return Stream.empty();
297        }
298
299        // Make sure mainClass is set for app jar
300        if (request.isFor(AppJarFileType) && mainClass() == null) {
301            throw new ConfigurationException().from(this)
302                .message("Main class must be set for %s", name());
303        }
304
305        // Upgrade to most specific type to avoid duplicate generation
306        if (mainClass() != null && !request.type().equals(AppJarFileType)) {
307            return (Stream<T>) context()
308                .resources(this, project().of(AppJarFileType));
309        }
310        if (mainClass() == null && !request.type().equals(JarFileType)) {
311            return (Stream<T>) context()
312                .resources(this, project().of(JarFileType));
313        }
314
315        // Prepare jar file
316        var destDir = destination();
317        if (!destDir.toFile().exists()) {
318            if (!destDir.toFile().mkdirs()) {
319                throw new ConfigurationException().from(this)
320                    .message("Cannot create directory " + destDir);
321            }
322        }
323        var jarResource = request.isFor(AppJarFileType)
324            ? AppJarFile.of(destDir.resolve(jarName()))
325            : LibraryJarFile.of(destDir.resolve(jarName()));
326        try {
327            buildJar(jarResource);
328        } finally {
329            // buidJar indirectly calls collectFromProviders which opens
330            // resources that are used in buildJar. Close them now.
331            for (var jarFile : openJars.values()) {
332                try {
333                    jarFile.close();
334                } catch (IOException e) { // NOPMD
335                    // Ignore, just trying to be nice.
336                }
337            }
338        }
339        return Stream.of((T) jarResource);
340    }
341}