java - 使用 snakeyaml(导入 junit 库)将 .yml 文件加载到 HashMap 中

Question

我正在尝试将 opencv 的 .yml 文件加载到 arrayLists 均值、投影和标签中。我已经创建了这三个数组列表，并且我正在尝试将 .yml 文件中的元素解析到它们中。我找到了 snakeYAML documentation 。但是我没有找到正确的方法。我正在尝试使用

  final String fileName = "train.yml";
  opencvmatrix mat = new opencvmatrix(); 
  Yaml yaml = new Yaml();

  try {
     InputStream ios = new FileInputStream(new File(fileName));

     // Parse the YAML file and return the output as a series of Maps and Lists
     Map<String,Object> result = (Map<String,Object>)yaml.load(ios);
     System.out.println(result.toString());
     Collection<Object> file = result.values();



  } catch (Exception e) {
     e.printStackTrace();
  }

我收到以下错误信息:

Exception in thread "main" while scanning a directive
in 'reader', line 1, column 1:
%YAML:1.0
^
expected alphabetic or numeric character, but found :(58)
in 'reader', line 1, column 6:
%YAML:1.0
     ^

at org.yaml.snakeyaml.scanner.ScannerImpl.scanDirectiveName(ScannerImpl.java:1269)
at org.yaml.snakeyaml.scanner.ScannerImpl.scanDirective(ScannerImpl.java:1221)
at org.yaml.snakeyaml.scanner.ScannerImpl.fetchDirective(ScannerImpl.java:614)
at org.yaml.snakeyaml.scanner.ScannerImpl.fetchMoreTokens(ScannerImpl.java:306)
at org.yaml.snakeyaml.scanner.ScannerImpl.checkToken(ScannerImpl.java:226)
at org.yaml.snakeyaml.parser.ParserImpl$ParseImplicitDocumentStart.produce(ParserImpl.java:195)
at org.yaml.snakeyaml.parser.ParserImpl.peekEvent(ParserImpl.java:158)
at org.yaml.snakeyaml.parser.ParserImpl.checkEvent(ParserImpl.java:143)
at org.yaml.snakeyaml.composer.Composer.getSingleNode(Composer.java:104)
at org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:120)
at org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:481)
at org.yaml.snakeyaml.Yaml.load(Yaml.java:412)
at projectCV.main(projectCV.java:33)
Java Result: 1

编辑 1:我注意到我的问题代表 assertEquals，它是 junit 库的类断言部分的函数。我无法找到一种方法将库正确导入到我的类路径中。我正在尝试两件事，下载 .jar 文件和 ADD/Jar 文件夹，并从项目属性->库->编译测试-> 添加库-> Junit 4.10。但我仍然遇到问题。

EDIT2:我将 YAML 1.0 更改为 YAML 1.1，但没有任何变化。我仍在尝试找到一种合适的方式来读取 yml 文件。

       final String fileName = "train.yml";
  opencvmatrix mat = new opencvmatrix(); 
  Yaml yaml = new Yaml();

  try {
     InputStream ios = new FileInputStream(new File(fileName));

     // Parse the YAML file and return the output as a series of Maps and Lists
     Map<String,Object> result = (Map<String,Object>)yaml.load(ios);
     System.out.println(result.toString());
     Collection<Object> file = result.values();



  } catch (Exception e) {
     e.printStackTrace();
  }

当我尝试运行我收到的代码时:

Exception in thread "main" Can't construct a java object for tag:yaml.org,2002:opencv- 
matrix; exception=Class not found: opencv-matrix
in 'reader', line 3, column 7:
mean: !!opencv-matrix
      ^

EDIT3:我已经创建了一个类 opencvmatrix(如 .yml 属性的名称)，具有属性行、列、dt、ArrayList 数据。 .yml 文件如下:

num_components: 19
num_components: 19
mean: !!opencvmatrix
rows: 1
cols: 3600
dt: d
data: [ 9.6842105263157890e+01, 1.0257894736842104e+02,
   1.0557894736842104e+02, 1.0794736842105263e+02,
   1.1752631578947367e+02, 1.1631578947368421e+02,
   1.1084210526315789e+02, 1.0373684210526315e+02,
   1.0052631578947368e+02, 9.5263157894736835e+01,
   9.0421052631578945e+01, 8.5631578947368411e+01,
   7.8684210526315780e+01, 7.2105263157894740e+01,
   6.9315789473684205e+01, 6.9105263157894740e+01,
   7.1052631578947370e+01, 7.9631578947368411e+01,
   9.0894736842105260e+01, 1.0121052631578947e+02,
   ....]
   projections:
   - !!opencvmatrix
   rows: 1
   cols: 19
   dt: d
   data: [ 1.6852352677811423e+03, -1.0112905042030820e+03,
      -1.3152188243875064e+03, 4.8298990155435700e+02,
      9.1980535900698968e+01, 6.5624763621018792e+02,
      -1.2380244625181117e+03, -1.8800931631152707e+02,
      -4.1473232893431384e+02, 5.7197035514178856e+02,
      4.9990276749703435e+02, 4.9062987890888604e+02,
      6.1928710580829818e+02, -1.2842392693864540e+03,
      2.4907719466932619e+01, 8.0299588479341844e+02,
      1.1621501008120421e+02, 1.0410492864645674e+02,
      8.5302163830384785e+01 ]
   - !!opencvmatrix
   rows: 1
   cols: 19
   dt: d
   data: [ -1.0313663745467784e+03, 1.9900404646205566e+03,
      -1.2844533156050284e+02, -4.3700867528097513e+02,
      6.6145551346834259e+02, -2.0562483671734990e+03,
      -1.9643774942432364e+02, 4.9329679854416281e+02,
      -2.0003326324501427e+02, 1.0737995038485865e+03,
      5.4161214984553695e+01, 4.7932826490658994e+02,
      8.6307152262273064e+02, 6.7413046532276610e+02,
      6.3835284527337114e+02, 4.1663169960066972e+02,
      3.5883912817427905e+01, -1.2935687563770381e+02,
      -1.6471877227400194e+03 ]
     ...
    labels: !!opencvmatrix
    rows: 1
    cols: 19
    dt: i
    data: [ 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3 ]

现在不更改主要代码，我收到以下错误:

   Can't construct a java object for tag:yaml.org,2002:opencvmatrix; exception=No single
   argument constructor found for class opencvmatrix
   in 'reader', line 1, column 7:
   mean: !!opencvmatrix
      ^

Answer 1

我终于尝试了上面的代码:

public static void main(String[] args) {
    // The path of your YAML file.
    final String fileName = "test.yml";
    ArrayList<String> key = new ArrayList<String>();
    ArrayList<String> value = new ArrayList<String>();
    Yaml yaml = new Yaml();

    try {
        InputStream ios = new FileInputStream(new File(fileName));

        // Parse the YAML file and return the output as a series of Maps and Lists
        Map< String, Object> result = (Map< String, Object>) yaml.load(ios);
        for (Object name : result.keySet()) {   

            key.add(name.toString());
            value.add(result.get(name).toString());    
        }

    } catch (Exception e) {
        e.printStackTrace();
    } 

     System.out.println(key + " " + value); }

它实际上读取 .yml 文件并返回文件的键和相应的值。我的问题是 value 包含其他对象，由于 yaml 文件的顺序，这些对象又包含其他 Maps。 Println 在终端中显示以上内容:

[mean, eigenvalues, eigenvectors, projections, labels] [opencvmatrix@16e70aa, opencvmatrix@1a6e106, opencvmatrix@ff8927, [opencvmatrix@859445, opencvmatrix@1c94782, opencvmatrix@175e958, opencvmatrix@2acdad, opencvmatrix@254927, opencvmatrix@1e5c67f, opencvmatrix@4ace42, opencvmatrix@12b710e, opencvmatrix@10b6d81, opencvmatrix@142691b, opencvmatrix@102985e, opencvmatrix@16168c4, opencvmatrix@25417f, opencvmatrix@1ef0642, opencvmatrix@183d912, opencvmatrix@1204e58, opencvmatrix@1f78fae, opencvmatrix@1f9fe08, opencvmatrix@194ddfb], opencvmatrix@7996db]

我怎样才能访问返回的嵌套对象？？？

Edit2:实际上我必须将返回的对象从 .yaml 文件转换为我必须定义的新类。所以我读取 .yml 元素(人脸识别器训练元素)的代码:

ArrayList<String> key = new ArrayList<String>();
    ArrayList<String> value = new ArrayList<String>();

    ArrayList<Object> obj = new ArrayList<Object>();
    ArrayList<Object> objected = new ArrayList<Object>();
    opencvmatrix mean = new opencvmatrix();
    opencvmatrix eigenValues = new opencvmatrix();
    opencvmatrix eigenVectors = new opencvmatrix();
    ArrayList<Object> opencvmatrix4 = new ArrayList<Object>();
    opencvmatrix labels = new opencvmatrix();
     opencvmatrix opencvmatrix6 = new opencvmatrix();
    ArrayList<ArrayList<Double>> projections = new ArrayList<ArrayList<Double>>();
    Yaml yaml = new Yaml();

    try {
        InputStream ios = new FileInputStream(new File(fileName));
        // Parse the YAML file and return the output as a series of Maps and Lists
        Map< String, Object> result = (Map< String, Object>) yaml.load(ios);
        for (Object name : result.keySet()) {
            key.add(name.toString());
            obj.add(result.get(name));
        }
    } catch (Exception e) {
        e.printStackTrace();
    }

    File file = new File("eigenvalues.txt");
    // creates the file
    file.createNewFile();
    // creates a FileWriter Object
    FileWriter writer = new FileWriter(file);
        // Writes the content to the file


    mean = (opencvmatrix) (obj.get(0));
    eigenValues = (opencvmatrix) (obj.get(1));
    eigenVectors = (opencvmatrix) (obj.get(2));

    opencvmatrix4 = (ArrayList<Object>) obj.get(3);

    for(int i=0; i<opencvmatrix4.size(); i++){

        opencvmatrix6 = (opencvmatrix)opencvmatrix4.get(i);
        projections.add(opencvmatrix6.data);
    }

    //System.out.println(projections.get(0).size());

    labels = (opencvmatrix) (obj.get(4));
    //System.out.println(obj3.data.size());

    writer.write(eigenVectors.data.get(0) + "      ");
    temp.add(eigenVectors.data.get(0));
    eigenMatrix.add(temp);

    for (int i = 1; i < eigenVectors.data.size(); i++) {

        if (i % 3600 == 0) {
            writer.write("\n");
            eigenMatrix.add(temp);
            temp.clear();

        }

         writer.write(eigenVectors.data.get(i) + "      ");
        temp.add(eigenVectors.data.get(i));

    }
    writer.flush();
    writer.close();