java - 如何使用Java在json数组中创建嵌套数组？

Question

我试图弄清楚如何使用 Java 在数组内创建嵌套数组。见下文:

{
    "fruit": [
        "apple"
    ],
    "color": [
        [                         <------ trying this!
            "red",
            "green"
        ]                         <------ trying this?
    ],
    "edible": true
}

但我只做到了这一点:

{
    "fruit": [
        "apple"
    ],
    "color": [
        "red",
        "green"
    ],
    "edible": true
}

到目前为止...这是我的代码:

Class with logic to create the json object

import java.util.List;

import com.fasterxml.jackson.annotation.JsonProperty;

public class FruitInventory {

    public List<String> fruit;
    public List<String> color;
    private String edible;

    public FruitInventory() {
    }

    public FruitInventory(List<String> fruit, List<String> color, String edible) {
        this.fruit = fruit;
        this.color = color;
        this.edible = edible;
    }

    @JsonProperty("fruit")
    public List<String> getfruit() {
        return fruit;
    }

    @JsonProperty("fruit")
    public void setfruit(List<String> fruit) {
        this.fruit = fruit;
    }

    @JsonProperty("color")
    public List<String> getcolor() {
        return color;
    }

    @JsonProperty("color")
    public void setcolor(List<String> color) {
        this.color = color;
    }

    @JsonProperty("edible")
    public String getedible() {
        return edible;
    }

    @JsonProperty("edible")
    public void setedible(String edible) {
        this.edible = edible;
    }

}

Method to print json

public static void main(String[] args) throws JsonProcessingException {
    FruitInventory fruitInventory = new FruitInventory();
    String json;
    ObjectMapper mapper = new ObjectMapper();

    List<String> fruit = new ArrayList<>();
    fruit.add("apple")

    List<String> color = new ArrayList<>();
    color.add("red");
    color.add("green");

    fruitInventory.setColumnNames(fruit);
    fruitInventory.setValues(color);

    json = mapper.writeValueAsString(fruitInventory);
    System.out.println(json);
}

我不确定是否应该在 color 内创建一个空数组列表，或者它如何适合我的代码示例。如果有人可以建议做什么，我更愿意您适本地采用/修改我的代码，因为这对我来说会更容易/更有意义。感谢任何帮助，谢谢! :)

Answer 1

更改public List<String> color;至public List<List<String>> color;根据你的 json 结构。

填充它的逻辑:

List<String> color = new ArrayList<>();
color.add("red");
color.add("green");

fruitInventory.setValues( Arrays.asList(color));