JarMerger.java

package com.github.rz7d.jarmerger;

import java.io.IOException;
import java.net.URI;
import java.nio.file.*;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.stream.Collectors;

public final class JarMerger {

    private JarMerger() {
    }

    public static void main(String[] args) throws Exception {
        System.out.println("JarMerger version 1.0.0");
        var origin = Paths.get(args.length > 0 ? args[0] : "F:\\Java\\JetBrains\\Products");

        var dest = origin.getParent().resolve(".merge");
        if (Files.notExists(dest)) {
            try {
                Files.createDirectories(dest);
            } catch (FileAlreadyExistsException ignored) {
            }
        }

        var map = new HashMap<Path, Collection<Path>>();

        for (var productPath : Files.list(origin).map(p -> p.resolve("lib")).toArray(Path[]::new)) {
            Files.list(productPath)
                .filter(Files::isRegularFile)
                .collect(Collectors.toMap(Path::getFileName, Path::toAbsolutePath)).forEach((k, v) -> {
                map.computeIfAbsent(k, __ -> new ArrayList<>()).add(v);
            });
        }

        map.forEach((k, v) -> {
            try {
                merge(dest, k, v);
            } catch (IOException exception) {
                exception.printStackTrace();
            }
        });
    }

    private static void merge(Path dest, Path name, Collection<Path> entities) throws IOException {
        var merged = dest.resolve(name);
        if (Files.exists(merged)) {
            System.out.printf("Merged data store %s is already exists!%n", merged);
            return;
        }
        System.out.printf("%s:%n", name);
        try (var fs = FileSystems.newFileSystem(URI.create("jar:" + merged.toUri()), Map.of("create", "true"))) {
            for (var entity : entities) {
                System.out.printf("   - %s%n", entity);
                try (var inFS = FileSystems.newFileSystem(URI.create("jar:" + entity.toUri()), Map.of())) {
                    for (var root : inFS.getRootDirectories()) {
                        for (var file : Files.walk(root).toArray(Path[]::new)) {
                            var d = fs.getPath(file.toString());
                            if (Files.exists(d))
                                continue;
                            if (Files.isDirectory(file)) {
                                try {
                                    Files.createDirectories(d);
                                } catch (FileAlreadyExistsException exception) {
                                    System.err.println("Warning: Directory " + d + " is already exists! (Make-Dirs)");
                                }
                            } else {
                                try {
                                    Files.copy(file, d);
                                } catch (FileAlreadyExistsException exception) {
                                    System.err.println("Warning: File " + d + " is already exists! (Copying-File)");
                                }
                            }
                        }
                    }
                }
            }
        }
    }

}