我是Android新手，并且在如何处理从API here检索到的数据方面遇到了困难。这是一个食谱。以下是一个例子。我正在努力的是创建一个jsonArray的所有项目，我可以用它来显示配方的详细视图中的成分和步骤。我可以获得id和名称，单个项目很好，特别是较大的配方数组中的成分和步骤数组是我不太正确的。
[{"id":2,
"name":"Brownies",
"ingredients":[{"quantity":350,"measure":"G","ingredient":"Bittersweet chocolate (60-70% cacao)"},
{"quantity":226,"measure":"G","ingredient":"unsalted butter"},
{"quantity":300,"measure":"G","ingredient":"granulated sugar"},
{"quantity":100,"measure":"G","ingredient":"light brown sugar"},
{"quantity":5,"measure":"UNIT","ingredient":"large eggs"},
{"quantity":1,"measure":"TBLSP","ingredient":"vanilla extract"},
{"quantity":140,"measure":"G","ingredient":"all purpose flour"},
{"quantity":40,"measure":"G","ingredient":"cocoa powder"},
{"quantity":1.5,"measure":"TSP","ingredient":"salt"},
{"quantity":350,"measure":"G","ingredient":"semisweet chocolate chips"}],
"steps":[{"id":0,"shortDescription":"Recipe Introduction","description":"Recipe Introduction","videoURL":"https:\/\/d17h27t6h515a5.cloudfront.net\/topher\/2017\/April\/58ffdc33_-intro-brownies\/-intro-brownies.mp4","thumbnailURL":""},
{"id":1,"shortDescription":"Starting prep","description":"1. Preheat the oven to 350�F. Butter the bottom and sides of a 9\"x13\" pan.","videoURL":"","thumbnailURL":""},
{"id":2,"shortDescription":"Melt butter and bittersweet chocolate.","description":"2. Melt the butter and bittersweet chocolate together in a microwave or a double boiler. If microwaving, heat for 30 seconds at a time, removing bowl and stirring ingredients in between.","videoURL":"https:\/\/d17h27t6h515a5.cloudfront.net\/topher\/2017\/April\/58ffdc43_1-melt-choclate-chips-and-butter-brownies\/1-melt-choclate-chips-and-butter-brownies.mp4","thumbnailURL":""},
{"id":3,"shortDescription":"Add sugars to wet mixture.","description":"3. Mix both sugars into the melted chocolate in a large mixing bowl until mixture is smooth and uniform.","videoURL":"","thumbnailURL":""},
{"id":4,"shortDescription":"Mix together dry ingredients.","description":"4. Sift together the flour, cocoa, and salt in a small bowl and whisk until mixture is uniform and no clumps remain. ","videoURL":"https:\/\/d17h27t6h515a5.cloudfront.net\/topher\/2017\/April\/58ffdc9e_4-sift-flower-add-coco-powder-salt-brownies\/4-sift-flower-add-coco-powder-salt-brownies.mp4","thumbnailURL":""},{"id":5,"shortDescription":"Add eggs.","description":"5. Crack 3 eggs into the chocolate mixture and carefully fold them in. Crack the other 2 eggs in and carefully fold them in. Fold in the vanilla.","videoURL":"https:\/\/d17h27t6h515a5.cloudfront.net\/topher\/2017\/April\/58ffdc62_2-mix-egss-with-choclate-butter-brownies\/2-mix-egss-with-choclate-butter-brownies.mp4","thumbnailURL":""},{"id":6,"shortDescription":"Add dry mixture to wet mixture.","description":"6. Dump half of flour mixture into chocolate mixture and carefully fold in, just until no streaks remain. Repeat with the rest of the flour mixture. Fold in the chocolate chips.","videoURL":"https:\/\/d17h27t6h515a5.cloudfront.net\/topher\/2017\/April\/58ffdcc8_5-mix-wet-and-cry-batter-together-brownies\/5-mix-wet-and-cry-batter-together-brownies.mp4","thumbnailURL":""},{"id":7,"shortDescription":"Add batter to pan.","description":"7. Pour the batter into the prepared pan and bake for 30 minutes.","videoURL":"https:\/\/d17h27t6h515a5.cloudfront.net\/topher\/2017\/April\/58ffdcf4_8-put-brownies-in-oven-to-bake-brownies\/8-put-brownies-in-oven-to-bake-brownies.mp4","thumbnailURL":""},{"id":8,"shortDescription":"Remove pan from oven.","description":"8. Remove the pan from the oven and let cool until room temperature. If you want to speed this up, you can feel free to put the pan in a freezer for a bit.","videoURL":"","thumbnailURL":""},{"id":9,"shortDescription":"Cut and serve.","description":"9. Cut and serve.","videoURL":"https:\/\/d17h27t6h515a5.cloudfront.net\/topher\/2017\/April\/58ffdcf9_9-final-product-brownies\/9-final-product-brownies.mp4","thumbnailURL":""}],
"servings":8,
"image":""}]
我一直试图用来处理这些数据。
public static String[] getSimpleRecipeStringsFromJson(Context context, String recipeJsonStr)
throws JSONException {
String[] parsedRecipeData = null;
JSONArray recipeJSONArray = new JSONArray(recipeJsonStr);
parsedRecipeData = new String[recipeJSONArray.length()];
// Loop through the recipe array
for (int i = 0; i < recipeJSONArray.length(); i++) {
JSONObject recipeDetails = recipeJSONArray.getJSONObject(i);
String recipeID = recipeDetails.getString("id");
String recipeName = recipeDetails.getString("name");
String recipeIngredients = recipeDetails.getString("ingredients");
String servings = recipeDetails.getString("servings");
String image = recipeDetails.getString("image");
String[] parsedRecipeIngredientsData = null;
JSONArray recipeIngredientsJSONArray = new JSONArray(recipeIngredients);
parsedRecipeIngredientsData = new String[recipeIngredientsJSONArray.length()];
// Loop through ingredients array
for (int ingredient = 0; ingredient < recipeIngredientsJSONArray.length(); ingredient++) {
JSONObject ingredientDetails = recipeIngredientsJSONArray.getJSONObject(ingredient);
String ingredientQuantity = ingredientDetails.getString("quantity");
String ingredientMeasure = ingredientDetails.getString("measure");
String ingredientIngredient = ingredientDetails.getString("ingredient");
parsedRecipeIngredientsData[ingredient] = "\"" + ingredientQuantity + "\",\"" + ingredientMeasure + "\",\"" + ingredientIngredient + "\"";
Log.d(TAG, "CHECK : " + parsedRecipeIngredientsData[ingredient]);
}
parsedRecipeData[i] = "[\"" + recipeID + "\",\"" + recipeName + "\",\"" + parsedRecipeIngredientsData + "]\",\"" + servings + "\",\"" + image + "\"]";
Log.d(TAG, "TAG : " + parsedRecipeData[i]);
}
return parsedRecipeData;
}
我在这样的详细视图中使用它，现在它只显示食谱名称，这是我需要所有信息的地方。
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.recipe_detail);
// Creating variables for each of the items we need to display
mRecipeName = (TextView) findViewById(R.id.recipe_name);
mRecipeIngredients = (TextView) findViewById(R.id.recipe_ingredients);
Intent intentThatStartedThisActivity = getIntent();
if (intentThatStartedThisActivity != null) {
if (intentThatStartedThisActivity.hasExtra(Intent.EXTRA_TEXT)) {
Context context = getApplicationContext();
mRecipe = intentThatStartedThisActivity.getStringExtra(Intent.EXTRA_TEXT);
try {
JSONArray jsonArray = new JSONArray(mRecipe);
String recipeID = jsonArray.getString(0);
// Display title
mRecipeName.setText(jsonArray.getString(1));
} catch (JSONException e) {
Log.d(TAG, "CHECK : " + e);
e.printStackTrace();
}
}
}
}
我希望我可以创建成分和步骤数组，我可以在以后循环但但我一直在收到错误。此代码生成的对象如下所示。
["4","Cheesecake","[Ljava.lang.String;@e5c064e}","8",""]
因此java.lang.string就是问题所在。我虽然创建一个String []会允许我稍后循环它，因为这是发送到此方法的数据，我只是试图复制它，但我无法让它解决。我收到了错误
unterminated array character at ### (the numbers change)
所以也许我只是错误地格式化它，或者我需要一种不同的方法。如果有人可以给我一个提示，告诉我如何将上面的食谱处理成可用的jsonArray，我可以使用它来填充视图，我将不胜感激。即使只是链接到要查看的示例或方法，也会非常感激。
答案 0 :(得分：1)
您可以使用gson更轻松地解析JSON数据。 在build.gradle文件中添加此依赖项。
compile 'com.google.code.gson:gson:2.8.0'
解析这样的数据
Gson gson = new Gson();
Data data= gson.fromJson(json,Data.class);
这是Data类
public class Data {
@SerializedName("id")
@Expose
public int id;
@SerializedName("name")
@Expose
public String name;
@SerializedName("ingredients")
@Expose
public List<Ingredient> ingredients = null;
@SerializedName("steps")
@Expose
public List<Step> steps = null;
@SerializedName("servings")
@Expose
public int servings;
@SerializedName("image")
@Expose
public String image;
}
这是成分类
public class Ingredient {
@SerializedName("quantity")
@Expose
public int quantity;
@SerializedName("measure")
@Expose
public String measure;
@SerializedName("ingredient")
@Expose
public String ingredient;
}
这是Step class
public class Step {
@SerializedName("id")
@Expose
public int id;
@SerializedName("shortDescription")
@Expose
public String shortDescription;
@SerializedName("description")
@Expose
public String description;
@SerializedName("videoURL")
@Expose
public String videoURL;
@SerializedName("thumbnailURL")
@Expose
public String thumbnailURL;
}
答案 1 :(得分：1)
我知道它没有直接回答答案，但是当谈到在android中序列化和反序列化Json时我建议使用GSON，谷歌的一个有用的库
通过使用它，您可以创建3个类，如下所示
public class Recipe {
@SerializedName("id")
public Integer id;
@SerializedName("name")
public String name;
@SerializedName("ingredients")
public List<Ingredient> ingredients = null;
@SerializedName("steps")
public List<Step> steps = null;
@SerializedName("servings")
public Integer servings;
@SerializedName("image")
public String image;
}
public class Ingredient {
@SerializedName("quantity")
public Double quantity;
@SerializedName("measure")
public String measure;
@SerializedName("ingredient")
public String ingredient;
}
public class Step {
@SerializedName("id")
public Integer id;
@SerializedName("shortDescription")
public String shortDescription;
@SerializedName("description")
public String description;
@SerializedName("videoURL")
public String videoURL;
@SerializedName("thumbnailURL")
public String thumbnailURL;
}
然后像这样解析你的JSON
private List<Recipe> mRecipes;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.recipe_detail);
// Creating variables for each of the items we need to display
mRecipeName = (TextView) findViewById(R.id.recipe_name);
mRecipeIngredients = (TextView) findViewById(R.id.recipe_ingredients);
Intent intentThatStartedThisActivity = getIntent();
if (intentThatStartedThisActivity != null) {
if (intentThatStartedThisActivity.hasExtra(Intent.EXTRA_TEXT)) {
Context context = getApplicationContext();
mRecipes = new Gson().fromJson(intentThatStartedThisActivity.getStringExtra(Intent.EXTRA_TEXT), new TypeToken<List<Recipe>>(){}.getType());
}
}
}
答案 2 :(得分：0)
要阅读数组，你必须像这样选择它们：
JSONArray recipeIngredients = recipeDetails.getJSONArray("ingredients");
JSONArray steps = recipeDetails.getJSONArray("steps");
不像字符串。
这样做，您可以遍历JSONArray并从中提取每个JSONObject。并形成JSONObject，你需要的字符串。
答案 3 :(得分：0)
您需要的是像GSON或Jakson这样的图书馆 这些库将把JSON变成一个pojo。 为此，您必须声明一个定义JSON响应模型的java类。
如果你使用android studio（为什么不是你！），我建议你安装一个名为DTO Generator的插件，这个插件会为你生成java类，所以你甚至不用打字所有的类和属性。
这些链接包含您需要的所有教程。 但是，大多数网络级库（如RETROFIT / OKHTTP）都允许您声明JSON解析器，因此他们将在每次网络调用中直接使用JSON库并将响应转换为POJO。
我不知道您使用的是哪个网络库，但我只是谷歌“如何使用gson进行改造”等等，并且有很多教程可以帮助您。
答案 4 :(得分：0)
如果您想使用Normal JSON解析，可以使用以下代码 解析发布的JSON的每个标记。
try {
JSONObject mainObj = new JSONObject("Your API Response");
String id = mainObj.getString("id");
String name = mainObj.getString("name");
String servings = mainObj.getString("servings");
String image = mainObj.getString("image");
JSONArray ingredients = mainObj.getJSONArray("ingredients");
for(int i=0;i<ingredients.length();i++){
JSONObject jobj = ingredients.getJSONObject(i);
String quantity = jobj.getString("quantity");
String measure = jobj.getString("measure");
String ingredient = jobj.getString("ingredient");
String chocolate = jobj.getString("chocolate");
}
JSONArray steps = mainObj.getJSONArray("steps");
for(int i=0;i<ingredients.length();i++){
JSONObject jobj = ingredients.getJSONObject(i);
String ids = jobj.getString("id");
String shortDescription = jobj.getString("shortDescription");
String description = jobj.getString("description");
String videoURL = jobj.getString("videoURL");
String thumbnailURL = jobj.getString("thumbnailURL");
}
} catch (Exception e) {
e.printStackTrace();
}