JSON对象/数组Java类

Question

我目前正在安卓 studio中为一个构造函数开发一个java类，其中的getter和setter试图使用JSON数组和对象。上面的代码示例是我的JSON数据格式，下面的代码是我的。JAVA类的方法，但我不确定数组哪里出了问题。我如何制作方法来添加成分（对象）、添加所有成分（数组）、获取一种成分（对象）和获取所有成分？（数组）

{"cocktails":[


{
    "cocktail_name": "Apple Martini",
    "cocktail_glass": "Martini",
    "cocktail_ingredients": [
      {
        "amount": 37.5,
        "measurement": "ml",
        "ingredient": "Ketel One Vodka"
      },
      {
        "amount": 12.5,
        "measurement": "ml",
        "ingredient": "Berentzen Apfel Korn"
      },
      {
        "amount": 25,
        "measurement": "ml",
        "ingredient": "Apple Juice"
      }
    ],
    "cocktail_recipe": [
      "first step",
      "second step",
      "third step"
    ],
    "cocktail_description": "Nam ultrices, libero non mattis pulvinar, nulla pede ullamcorper augue, a suscipit nulla elit ac nulla. Sed vel enim sit amet nunc viverra dapibus. Nulla suscipit ligula in lacus.",
    "cocktail_garnish": [
      {
        "amount": 1,
        "measurement": "wedge",
        "ingredient": "Apple"
      }
    ],
    "cocktail_alcoholic": true,
    "cocktail_barware": ["bostin tin","bar spoon","strainer","match/lighter"],
    "cocktail_tags": ["Green","Vodka","Martini","Medium","Ketel One", "Berentzen Apfel Korn", "Liquer", "Apple"],
    "cocktail_img_id": "pic.jpeg",
    "cocktail_video_id": "https://youtu.be/z4yL2xrI0RY"
  }]}




public final class cocktail {
       private String name;
       private String glass;
       private JSONArray ingredients; //this is now a json array
       private String[] recipe;
       private String description;
       private JSONArray garnish; //this is a json array aswell
       private Boolean alcoholic;
       //private Float Abv;
      private String[] barware;
      private String[] tags;
      private String image;
      private String video;

      // constructor
      public cocktail(String name, String glass, JSONArray ingredients,       String[] recipe, String description, JSONArray garnish, Boolean alcoholic, String[] barware, String[] tags, String image, String video) {
      this.name = name;
      this.glass = glass;
      this.ingredients = ingredients;
      this.recipe = recipe;
      this.description = description;
      this.garnish = garnish;
      this.alcoholic = alcoholic;
      //this.Abv = Abv;
      this.barware = barware;
      this.tags = tags;
      this.image = image;
      this.video = video;
      }

      //Get method for grabbing an ingredient from the ingredients list of "this" cocktail //change
     public JSONObject getIngredient(String ingred) {
     JSONArray ingred = this.ingredients;

    ingredientObj = getJSONObject()

    }

//Method for setting an ingredient of index i of "this" cocktail
public void setIngredient(Integer amount, String measurement, String ing) {
    JSONObject ingredientObject = new JSONObject();

    ingredientObject.put("amount",amount);
    ingredientObject.put("measurement",measurement);
    ingredientObject.put("ingredient",ing);

    this.ingredients.add(ingredientObject);
}}

Answer 1

下面是一个测试类和相应的代码。添加您正在考虑的其他字段应该相当简单。看起来大部分问题都是在JSON对象和常规Java类型之间的转换

对于这样的事情，您可能需要考虑使用一个像^ {A1}这样的库来从POJOs自动转换到JSON对象。

鸡尾酒测试。爪哇

import org.json.JSONArray;
import org.json.JSONObject;
import org.junit.Test;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;


public class CocktailTest {

    @Test
    public void addOneIngredient() {
        Cocktail cocktail = new Cocktail();
        cocktail.addIngredient("whiskey", 5);

        assertThat(cocktail.root.toString(), is("{\"ingredients\":[{\"amount\":5,\"name\":\"whiskey\"}]}"));

    }
    @Test
    public void addTwoIngredients() {
        Cocktail cocktail = new Cocktail();
        cocktail.addIngredient("whiskey", 5);
        cocktail.addIngredient("olive", 2);

        assertThat(cocktail.root.toString(), is("{\"ingredients\":[{\"amount\":5,\"name\":\"whiskey\"},{\"amount\":2,\"name\":\"olive\"}]}"));
    }

    @Test
    public void getOneIngredient() {
        Cocktail cocktail = new Cocktail();
        cocktail.addIngredient("whiskey", 5);
        JSONObject ingredient = cocktail.getIngredient("whiskey");

        assertThat(ingredient.get("name"), is("whiskey"));
        assertThat(ingredient.get("amount"), is(5));
    }

    @Test
    public void getAllIngredients() {
        Cocktail cocktail = new Cocktail();
        cocktail.addIngredient("whiskey", 5);
        cocktail.addIngredient("olive", 2);
        JSONArray ingredients = cocktail.getIngredients();

        JSONObject whiskey = ingredients.getJSONObject(0);
        assertThat(whiskey.get("name"), is("whiskey"));
        assertThat(whiskey.get("amount"), is(5));

        JSONObject olive = ingredients.getJSONObject(1);
        assertThat(olive.get("name"), is("olive"));
        assertThat(olive.get("amount"), is(2));
    }
}

鸡尾酒。爪哇

import org.json.JSONArray;
import org.json.JSONObject;

public class Cocktail {
    public final JSONObject root = new JSONObject();

    public Cocktail() {
       root.put("ingredients", new JSONArray()) ;
    }

    public void addIngredient(String ingredientName, int amount) {

        JSONObject ingredient = new JSONObject();
        ingredient.put("name", ingredientName);
        ingredient.put("amount", amount);
        JSONArray ingredients = (JSONArray) root.get("ingredients");
        ingredients.put(ingredient);
    }

    public JSONObject getIngredient(String ingredientName) {
        JSONArray ingredients = (JSONArray) root.get("ingredients");
        for (Object ingredientObj: ingredients ) {
            JSONObject ingredient = (JSONObject)ingredientObj;
            if (ingredient.get("name").equals(ingredientName)) {
                return ingredient;
            }
        }

        throw new IllegalArgumentException("Couldn't find " + ingredientName);
    }

    public JSONArray getIngredients() {
        return root.getJSONArray("ingredients");
    }
}