// Copyright 2010-2025 Google LLC

// 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.google.ortools;

import com.sun.jna.Platform;

import java.io.IOException;

import java.net.URI;

import java.net.URISyntaxException;

import java.net.URL;

import java.nio.file.FileSystem;

import java.nio.file.FileSystemAlreadyExistsException;

import java.nio.file.FileSystems;

import java.nio.file.FileVisitResult;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.SimpleFileVisitor;

import java.nio.file.attribute.BasicFileAttributes;

import java.util.AbstractMap;

import java.util.Arrays;

import java.util.Collections;

import java.util.List;

import java.util.Map;

import java.util.Objects;

/** Load native libraries needed for using ortools-java. */

public class Loader {

private static final String RESOURCE_PATH = "ortools-" + Platform.RESOURCE_PREFIX + "/";

/** Try to locate the native libraries directory. */

private static URI getNativeResourceURI() throws IOException {

ClassLoader loader = Loader.class.getClassLoader();

URL resourceURL = loader.getResource(RESOURCE_PATH);

Objects.requireNonNull(resourceURL,

String.format("Resource %s was not found in ClassLoader %s", RESOURCE_PATH, loader));

URI resourceURI;

try {

resourceURI = resourceURL.toURI();

} catch (URISyntaxException e) {

throw new IOException(e);

}

return resourceURI;

}

@FunctionalInterface

private interface PathConsumer<T extends IOException> {

void accept(Path path) throws T;

}

/**

* Extract native resources in a temp directory.

*

* @param resourceURI Native resource location.

* @return The directory path containing all extracted libraries.

*/

private static Path unpackNativeResources(URI resourceURI) throws IOException {

Path tempPath;

tempPath = Files.createTempDirectory("ortools-java");

tempPath.toFile().deleteOnExit();

PathConsumer<?> visitor;

visitor = (Path sourcePath) -> Files.walkFileTree(sourcePath, new SimpleFileVisitor<Path>() {

@Override

public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {

Path newPath = tempPath.resolve(sourcePath.getParent().relativize(file).toString());

Files.copy(file, newPath);

newPath.toFile().deleteOnExit();

return FileVisitResult.CONTINUE;

}

@Override

public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs)

throws IOException {

Path newPath = tempPath.resolve(sourcePath.getParent().relativize(dir).toString());

Files.copy(dir, newPath);

newPath.toFile().deleteOnExit();

return FileVisitResult.CONTINUE;

}

});

FileSystem fs;

try {

fs = FileSystems.newFileSystem(resourceURI, Collections.emptyMap());

} catch (FileSystemAlreadyExistsException e) {

fs = FileSystems.getFileSystem(resourceURI);

if (fs == null) {

throw new IllegalArgumentException();

}

}

Path p = fs.provider().getPath(resourceURI);

visitor.accept(p);

return tempPath;

}

/** Unpack and Load the native libraries needed for using ortools-java. */

private static boolean loaded = false;

public static synchronized void loadNativeLibraries() {

// prints the name of the Operating System

// System.out.println("OS: " + System.getProperty("os.name"));

if (loaded) {

return;

}

try {

// System.out.println("System.loadLibrary(\"jniortools\")");

System.loadLibrary("jniortools");

loaded = true;

return;

} catch (UnsatisfiedLinkError e) {

// Do nothing.

// System.out.println("Can't System.loadLibrary(jniortools)");

}

try {

URI resourceURI = getNativeResourceURI();

Path tempPath = unpackNativeResources(resourceURI);

// Load the native library

// System.out.println("System.load(" + System.mapLibraryName("jniortools") + ")");

System.load(tempPath.resolve(RESOURCE_PATH)

.resolve(System.mapLibraryName("jniortools"))

.toAbsolutePath()

.toString());

loaded = true;

return;

} catch (IOException | UnsatisfiedLinkError e) {

// Do nothing.

// System.out.println("Can't System.load(jniortools)");

}

// On windows, try to load each libraries one by one.

// System.out.println("Prefix: " + Platform.RESOURCE_PREFIX);

if (Platform.RESOURCE_PREFIX.equals("win32-x86-64")) {

try {

URI resourceURI = getNativeResourceURI();

Path tempPath = unpackNativeResources(resourceURI);

// libraries order does matter <LibraryName, isMandatory> !

List<Map.Entry<String, Boolean>> dlls =

Arrays.asList((new AbstractMap.SimpleEntry("zlib1", true)),

(new AbstractMap.SimpleEntry("bz2", true)),

(new AbstractMap.SimpleEntry("abseil_dll", true)),

(new AbstractMap.SimpleEntry("re2", true)),

(new AbstractMap.SimpleEntry("libutf8_validity", true)),

(new AbstractMap.SimpleEntry("libprotobuf", true)),

(new AbstractMap.SimpleEntry("highs", false)),

(new AbstractMap.SimpleEntry("libscip", false)),

(new AbstractMap.SimpleEntry("ortools", true)),

(new AbstractMap.SimpleEntry("jniortools", true)));

for (Map.Entry<String, Boolean> dll : dlls) {

try {

// System.out.println("System.load(" + dll.getKey() + ")");

System.load(tempPath.resolve(RESOURCE_PATH)

.resolve(System.mapLibraryName(dll.getKey()))

.toAbsolutePath()

.toString());

} catch (UnsatisfiedLinkError e) {

System.out.println("System.load(" + dll.getKey() + ") failed!");

if (dll.getValue()) {

throw new RuntimeException(e);

}

}

}

loaded = true;

return;

} catch (IOException e) {

// Do nothing.

// System.out.println("unpack failed");

}

}

}

}