JSONGenerator 如何在 JSON 中输出一个对象

Question

I want to output the following JSON:

result: {
    "x": 11,
    "y": 10,
    "actions": [
    ],
    "localConfigurations": {
         "local1": {},
         "local2":  {}
    }
}

I have the following code:

public class Configuration {
    private int fX;
    private int fY;
    private Actions[] fActions;
    private LinkedHashMap<String, LocalConfiguration> fLocalConfigurations = new LinkedHashMap<>();

    @JsonProperty("x")
    public int getX() { return fX; }
    public void setX(int x) { fX = x; }

    @JsonProperty("y")
    // getter and setter for y

    @JsonProperty("actions")
    // getter and setter for actions

    @JsonProperty("localConfigurations")
    // getter and setter for localConfigurations
}

Below is the code that I am trying to use to output the JSON:

    JsonFactory factory = new JsonFactory();
    JsonGenerator generator = factory.createGenerator(fOutputStream);

    generator.writeStartObject();
    generator.writeArrayFieldStart("result");

    if (configuration != null)
        mapper.writeValue(generator, configuration);

    generator.writeEndArray();
    generator.writeEndObject();
    generator.close();

However, my output turns out as:

result: [{
    "x": 11,
    "y": 10,
    "actions": [
    ],
    "localConfigurations": {
         "local1": {},
         "local2":  {}
    }
}]

I am not sure how I can achieve the desired output, without using the generator.writeArrayFieldStart. If I use only writeStartObject and dump the object Configuration, the JSON output throws some errors instead. So, how can I get the output as I want? thanks

Answer 1

You need to open object, write property, write Configuration POJO and close object.

generator.writeStartObject();
generator.writeFieldName("result");

objectMapper.writeValue(generator, configuration);

generator.writeEndObject();