使用傑克遜將Yaml讀取為對象

Question

我有Yaml，看起來像這樣：

data_lists:
      list1:(dynamic name)  
        - AA: true
          BB: true
          CC: "value"
        - AA: false
          BB: true
          CC: "value2"

我想要得到的是將其存儲到對象

class BLA{
private boolean AA;
private boolean BB;
private String CC;

//getters and setters

}

我正在使用傑克遜庫，但可以找到如何忽略根元素（如data_lsts和list1）並僅存儲數組對象。

我當前的代碼是：

ObjectMapper mapper = new ObjectMapper(YAML_FACTORY);
List<BLA> bla = Arrays.asList(mapper.readValue(ymlFile, BLA.class));

Answer 1

給定您的示例，您可以使用TypeReference並將文件描述為Map<String, Map<String, List<BLA>>>

private static final String yamlString =
    "data_lists:\n" +
    "      list1:  \n" +
    "        - AA: true\n" +
    "          BB: true\n" +
    "          CC: \"value\"\n" +
    "        - AA: false\n" +
    "          BB: true\n" +
    "          CC: \"value2\"";

public static void main(String[] args) throws Exception {
    ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
    Map<String, Map<String, List<BLA>>> fileMap = mapper.readValue(
        yamlString, 
        new TypeReference<Map<String, Map<String, List<BLA>>>>(){});
    Map<String, List<BLA>> dataLists = fileMap.get("data_lists");
    List<BLA> blas = dataLists.get("list1");
    System.out.println(blas);
}

class BLA {
    @JsonProperty("AA")
    private boolean aa;
    @JsonProperty("BB")
    private boolean bb;
    @JsonProperty("CC")
    private String cc;

    @Override
    public String toString() {
        return aa + "|" + bb + "|" + cc;
    }

    // Getters/Setters
}

這個輸出

[true|true|value, false|true|value2]

如果您有這樣的列表列表：

data_lists:
  list1:  
    - AA: true
      BB: true
      CC: "value"
    - AA: false
      BB: true
      CC: "value2"
  list2:  
    - AA: true
      BB: true
      CC: "value3"
    - AA: false
      BB: true
      CC: "value4"

您可以獲取"data_lists"值作為集合

Map<String, List<BLA>> dataLists = fileMap.get("data_lists");
Collection<List<BLA>> blas = dataLists.values();
System.out.println(blas);

輸出：

[[true|true|value, false|true|value2], [true|true|value3, false|true|value4]]