如何在 macOS 上为 IntelliJ 项目安装 Google OR-Tools

Posted

技术标签:

【中文标题】如何在 macOS 上为 IntelliJ 项目安装 Google OR-Tools【英文标题】：How to install Google OR-Tools for an IntelliJ project on macOS 【发布时间】：2019-05-25 08:28:27 【问题描述】：

我正在尝试为 Google OR-Tools 运行 VRP Java 示例，但不断收到 UnsatisfiedLinkError: no jniortools in java.library.path 错误。

我所做的是：

    下载binary distribution for Java/macOS 新建一个基于 Gradle 的 IntelliJ 项目 在项目的根目录中创建一个名为lib 的新文件夹 复制并粘贴名为的 Goole OR-Tools 文件 com.google.ortools.jar 和 protobuf.jar（在 lib 在步骤 1) 中下载的二进制分发的文件夹到lib 在第 3 步中创建的文件夹。 转到项目结构 > 模块 > 主 > 依赖项 > + > JAR 或目录 > 从 project_root/lib 中选择 com.google.ortools.jar 和 protobuf.jar 运行 google or-tools 网站上的 java example

这是java示例的完整代码：

// Copyright 2010-2018 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.

// [START program]
// [START import]
import com.google.ortools.constraintsolver.Assignment;
import com.google.ortools.constraintsolver.FirstSolutionStrategy;
import com.google.ortools.constraintsolver.RoutingDimension;
import com.google.ortools.constraintsolver.RoutingIndexManager;
import com.google.ortools.constraintsolver.RoutingModel;
import com.google.ortools.constraintsolver.RoutingSearchParameters;
import com.google.ortools.constraintsolver.main;
import java.util.logging.Logger;
// [END import]

/** Minimal VRP.*/
public class VrpGlobalSpan 
  static 
    System.loadLibrary("jniortools");
  

  private static final Logger logger = Logger.getLogger(VrpGlobalSpan.class.getName());

  // [START data_model]
  static class DataModel 
    public final long[][] distanceMatrix = 
        0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354, 468, 776, 662,
        548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674, 1016, 868, 1210,
        776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164, 1130, 788, 1552, 754,
        696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822, 1164, 560, 1358,
        582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708, 1050, 674, 1244,
        274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628, 514, 1050, 708,
        502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856, 514, 1278, 480,
        194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320, 662, 742, 856,
        308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662, 320, 1084, 514,
        194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388, 274, 810, 468,
        536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764, 730, 388, 1152, 354,
        502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114, 308, 650, 274, 844,
        388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194, 536, 388, 730,
        354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0, 342, 422, 536,
        468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536, 342, 0, 764, 194,
        776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274, 388, 422, 764, 0, 798,
        662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730, 536, 194, 798, 0,
    ;
    public final int vehicleNumber = 4;
    public final int depot = 0;
  
  // [END data_model]

  // [START solution_printer]
  /// @brief Print the solution.
  static void printSolution(
      DataModel data, RoutingModel routing, RoutingIndexManager manager, Assignment solution) 
    // Inspect solution.
    long maxRouteDistance = 0;
    for (int i = 0; i < data.vehicleNumber; ++i) 
      long index = routing.start(i);
      logger.info("Route for Vehicle " + i + ":");
      long routeDistance = 0;
      String route = "";
      while (!routing.isEnd(index)) 
        route += manager.indexToNode(index) + " -> ";
        long previousIndex = index;
        index = solution.value(routing.nextVar(index));
        routeDistance += routing.getArcCostForVehicle(previousIndex, index, i);
      
      logger.info(route + manager.indexToNode(index));
      logger.info("Distance of the route: " + routeDistance + "m");
      maxRouteDistance = Math.max(routeDistance, maxRouteDistance);
    
    logger.info("Maximum of the route distances: " + maxRouteDistance + "m");
  
  // [END solution_printer]

  public static void main(String[] args) throws Exception 
    // Instantiate the data problem.
    // [START data]
    final DataModel data = new DataModel();
    // [END data]

    // Create Routing Index Manager
    // [START index_manager]
    RoutingIndexManager manager =
        new RoutingIndexManager(data.distanceMatrix.length, data.vehicleNumber, data.depot);
    // [END index_manager]

    // Create Routing Model.
    // [START routing_model]
    RoutingModel routing = new RoutingModel(manager);
    // [END routing_model]

    // Create and register a transit callback.
    // [START transit_callback]
    final int transitCallbackIndex =
        routing.registerTransitCallback((long fromIndex, long toIndex) -> 
          // Convert from routing variable Index to user NodeIndex.
          int fromNode = manager.indexToNode(fromIndex);
          int toNode = manager.indexToNode(toIndex);
          return data.distanceMatrix[fromNode][toNode];
        );
    // [END transit_callback]

    // Define cost of each arc.
    // [START arc_cost]
    routing.setArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
    // [END arc_cost]

    // Add Distance constraint.
    // [START distance_constraint]
    routing.addDimension(transitCallbackIndex, 0, 3000,
        true, // start cumul to zero
        "Distance");
    RoutingDimension distanceDimension = routing.getMutableDimension("Distance");
    distanceDimension.setGlobalSpanCostCoefficient(100);
    // [END distance_constraint]

    // Setting first solution heuristic.
    // [START parameters]
    RoutingSearchParameters searchParameters =
        main.defaultRoutingSearchParameters()
            .toBuilder()
            .setFirstSolutionStrategy(FirstSolutionStrategy.Value.PATH_CHEAPEST_ARC)
            .build();
    // [END parameters]

    // Solve the problem.
    // [START solve]
    Assignment solution = routing.solveWithParameters(searchParameters);
    // [END solve]

    // Print solution on console.
    // [START print_solution]
    printSolution(data, routing, manager, solution);
    // [END print_solution]
  

// [END program]

com.google.ortools.* 导入很好，但在运行 java 示例时出现以下错误：

Exception in thread "main" java.lang.UnsatisfiedLinkError: no jniortools in java.library.path
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1867)
    at java.lang.Runtime.loadLibrary0(Runtime.java:870)
    at java.lang.System.loadLibrary(System.java:1122)
    at VrpGlobalSpan.<clinit>(VrpGlobalSpan.java:29)

我搜索了jniortools 文件，但在任何地方都找不到。我该怎么做才能确保示例运行？

【问题讨论】：

找到解决办法了吗？你能在这里更新一下吗？我也遇到同样的问题等待解决方案。 【参考方案1】：

所有的库，包括libjniortools.dylib都在lib目录下， 你需要在intellij中添加安装lib目录的路径。

见How to set the java.library.path in intelliJ Idea

【讨论】：

【参考方案2】：

手动指出jar 依赖项的位置，如here 所述。

你应该得到这样的结果。

在Maven 上也有一些独立的发布，我相信官方是on its way

【讨论】：

以上是关于如何在 macOS 上为 IntelliJ 项目安装 Google OR-Tools的主要内容，如果未能解决你的问题，请参考以下文章

MobileFirst 6.3 本机 API 项目在 MacOS 上为空 /include 文件夹

如何在 macOS 上为 Qt 窗口使用 Objective-C 变量和方法？

如何在 MacOS 12 上为 php 7.1 安装 mcrypt 扩展以进行 Laravel 开发？

如何在同一设备上为不同的项目使用两个版本的颤振？

如何在 macos 上为 ffmpeg 启用 libx264

如何在 Windows 上为 WebStorm 或 IntelliJ IDEA 使用 Mac OSX 键盘映射？