如何从JSON数据文件创建JSON数组? [英] How to create JSON array from JSON data file?

问题描述

是Android的新手.我正在创建一个解析JSON数据并将其显示在ListView中的android项目.我正在使用Eclipse创建项目.我在原始文件夹中创建了一个名为userinput.json的文件，该文件是res的子文件夹.我已经在文件中提供了这些JSON数据.

Am new to android. Am creating an android project which parses the JSON data and displays it in a ListView. Am using Eclipse to create the project. I have created a file called userinput.json in the raw folder which is subfolder of res. I have given these JSON data inside the file.

 [
  {"name":"Company A", "hometown":"NJ"},
  {"name":"Company B", "hometown":"PA"},
  {"name":"Company C", "hometown":"CT"},
  {"name":"Company D", "hometown":"NY"},
  {"name":"Company E", "hometown":"NJ"}
  ]

我的要求是将原始资源中声明的JSON数据转换为JSON数组. 由于我已经在文件中声明了json数据，因此我必须从资源中访问它，因此我使用BufferedReader来读取文件. 但是，当尝试将StringBuilder对象转换为JSON数组时，返回的值为null. 这是我编写的代码:

My requirement is to convert this JSON data declared in the Raw resources into JSON array. Since I have declared the json data in a file, I have to access it from the resources and hence I use BufferedReader to read the file. But while trying to convert the StringBuilder object to JSON array, I am returned with null. This is the code I have written:

BufferedReader jsonReader = new BufferedReader(new InputStreamReader(
                this.getResources().openRawResource(R.raw.userinput)));
StringBuilder jsonBuilder = new StringBuilder();
try {
        for (String line = null; (line = jsonReader.readLine()) != null;)
        {
                jsonBuilder.append(line).append("\n");
        }
        jTokener = new JSONTokener(jsonBuilder.toString());
        jsonArray = new JSONArray(jTokener.toString());
    } 
    catch (Exception e) 
    {
        throw new RuntimeException(e);
    }
ArrayList<User> newArrayOfUsers = User.JsonData(jsonArray);

在单独的Java文件中，我有以下两种方法将JSON数组转换为Java对象:

In a seperate Java file I have the below two methods to convert my JSON Array into Java Objects:

public User(JSONObject object)
    {
        try
        {
            this.name = object.getString(name);
            this.hometown = object.getString(hometown);
        }
        catch(JSONException e)
        {
            e.printStackTrace();
        }
    }

public static ArrayList<User> JsonData(JSONArray jsonArray)
    {
        ArrayList<User> users = new ArrayList<User>();
        for(int i = 0; i < jsonArray.length(); i++)
        {
            try
            {
                users.add(new User(jsonArray.getJSONObject(i)));
            }
            catch(JSONException e)
            {
                e.printStackTrace();
            }
        }
        return users;
    }

我不确定是否以正确的方式执行此操作，有人可以指导我如何从StringBuilder获取JSON数组吗?

I am not sure, whether am doing this in correct way, Can anyone please guide me how to get JSON array from the StringBuilder?

推荐答案

这有效...

BufferedReader jsonReader = new BufferedReader(new InputStreamReader(
            this.getResources().openRawResource(R.raw.userinput)));
    StringBuilder jsonBuilder = new StringBuilder();
    try {
        for (String line = null; (line = jsonReader.readLine()) != null;) {
            jsonBuilder.append(line).append("\n");
        }
        Toast.makeText(this, jsonBuilder.toString(), 1).show();
        //JSONTokener jTokener = new JSONTokener(jsonBuilder.toString());
        JSONArray jsonArray = new JSONArray(jsonBuilder.toString());

        for(int i=0;i<jsonArray.length();i++)
        {
            JSONObject tmpjsonobject=jsonArray.getJSONObject(i);
            Toast.makeText(this, tmpjsonobject.getString("name")+"\n"+tmpjsonobject.getString("hometown"), 1).show();
        }
    } catch (Exception e) {
        throw new RuntimeException(e);
    }

@Salvin是正确的...不需要JsonTokener .....

and @Salvin is right ...there is no need for JsonTokener .....

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