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1   /*
2    * Portions of this software was developed by employees of the National Institute
3    * of Standards and Technology (NIST), an agency of the Federal Government and is
4    * being made available as a public service. Pursuant to title 17 United States
5    * Code Section 105, works of NIST employees are not subject to copyright
6    * protection in the United States. This software may be subject to foreign
7    * copyright. Permission in the United States and in foreign countries, to the
8    * extent that NIST may hold copyright, to use, copy, modify, create derivative
9    * works, and distribute this software and its documentation without fee is hereby
10   * granted on a non-exclusive basis, provided that this notice and disclaimer
11   * of warranty appears in all copies.
12   *
13   * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
14   * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
15   * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
16   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
17   * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
18   * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
19   * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
20   * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
21   * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
22   * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
23   * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
24   * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
25   */
26  
27  package gov.nist.secauto.metaschema.databind.io.yaml;
28  
29  import org.json.JSONException;
30  import org.json.JSONObject;
31  import org.yaml.snakeyaml.DumperOptions;
32  import org.yaml.snakeyaml.LoaderOptions;
33  import org.yaml.snakeyaml.Yaml;
34  import org.yaml.snakeyaml.constructor.Constructor;
35  import org.yaml.snakeyaml.nodes.Tag;
36  import org.yaml.snakeyaml.representer.Representer;
37  import org.yaml.snakeyaml.resolver.Resolver;
38  
39  import java.io.BufferedReader;
40  import java.io.IOException;
41  import java.nio.charset.StandardCharsets;
42  import java.nio.file.Files;
43  import java.nio.file.Path;
44  import java.util.Map;
45  
46  import edu.umd.cs.findbugs.annotations.NonNull;
47  
48  public final class YamlOperations {
49    private static final Yaml YAML_PARSER;
50  
51    static {
52      LoaderOptions loaderOptions = new LoaderOptions();
53      loaderOptions.setCodePointLimit(Integer.MAX_VALUE - 1); // 2GB
54      Constructor constructor = new Constructor(loaderOptions);
55      DumperOptions dumperOptions = new DumperOptions();
56      Representer representer = new Representer(dumperOptions);
57      YAML_PARSER = new Yaml(constructor, representer, dumperOptions, loaderOptions, new Resolver() {
58        @Override
59        protected void addImplicitResolvers() {
60          addImplicitResolver(Tag.BOOL, BOOL, "yYnNtTfFoO");
61          addImplicitResolver(Tag.INT, INT, "-+0123456789");
62          addImplicitResolver(Tag.FLOAT, FLOAT, "-+0123456789.");
63          addImplicitResolver(Tag.MERGE, MERGE, "<");
64          addImplicitResolver(Tag.NULL, NULL, "~nN\0");
65          addImplicitResolver(Tag.NULL, EMPTY, null);
66          // addImplicitResolver(Tag.TIMESTAMP, TIMESTAMP, "0123456789");
67        }
68      });
69    }
70  
71    private YamlOperations() {
72      // disable construction
73    }
74  
75    /**
76     * Parse the data represented in YAML in the provided {@code target}, producing
77     * an mapping of field names to Java object values.
78     *
79     * @param target
80     *          the YAML file to parse
81     * @return the mapping of field names to Java object values
82     * @throws IOException
83     *           if an error occurred while parsing the YAML content
84     */
85    @SuppressWarnings({ "unchecked", "null" })
86    @NonNull
87    public static Map<String, Object> parseYaml(Path target) throws IOException {
88      try (BufferedReader reader = Files.newBufferedReader(target.toAbsolutePath(), StandardCharsets.UTF_8)) {
89        return (Map<String, Object>) YAML_PARSER.load(reader);
90      }
91    }
92  
93    /**
94     * Converts the provided YAML {@code map} into JSON.
95     *
96     * @param map
97     *          the YAML map
98     * @return the JSON object
99     * @throws JSONException
100    *           if an error occurred while building the JSON tree
101    */
102   public static JSONObject yamlToJson(@NonNull Map<String, Object> map) {
103     return new JSONObject(map);
104   }
105 }