解析Yaml文件时出错-无法为JavaBean创建属性

Question

Yaml file contains:

test:
  subHeading: "1234"

Model.java

class Model{
  @JsonProperty("test")
  private SubHeading subHead;

  private class SubHeading{
     @JsonProperty("subHeading")
      private String text;
  }

I try to parse above Yaml content as follows:

Yaml yaml = new Yaml(new Constructor(Model.class));
System.out.println(yaml.load(new FileReader(PATH)).toString());

I immediately get an exception:

Cannot create property=test for JavaBean=Model@13a5fe33
 in 'reader', line 1, column 1:
    test:

Any idea what I am doing wrong and what I can change here?

Answer 1

Fist of all you use Jackson annotation but SnakeYaml library to read a yaml file. You have to simplify your solution by:

1. Simplifying model
2. Use Jackson
3. Removing Jackson annotation in cases where properties have the same name as values in annotation.

Model
Create each class as public class in new file.

public class Model {

    private SubHeading test;

    public SubHeading getTest() {
        return test;
    }

    public void setTest(SubHeading test) {
        this.test = test;
    }

    @Override
    public String toString() {
        return "Model{" +
                "test=" + test +
                '}';
    }
}

and

public class SubHeading {
    private String subHeading;

    public String getSubHeading() {
        return subHeading;
    }

    public void setSubHeading(String subHeading) {
        this.subHeading = subHeading;
    }

    @Override
    public String toString() {
        return "SubHeading{" +
                "subHeading='" + subHeading + '\'' +
                '}';
    }
}

Example usage:

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;

public class YamlTest {

    public static void main(String[] args) throws Exception {
        ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
        mapper.enable(SerializationFeature.INDENT_OUTPUT);

        String text = "test:\n" +
                "  subHeading: \"1234\"";

        Model model = mapper.readValue(text, Model.class);
        System.out.println(model);
    }
}

Above prints:

Model{test=SubHeading{subHeading='1234'}}