通过 URL 从 JSON 数据中获取数据并使用列表视图或回收器视图将其显示在 android 应用程序中

Posted 2023-04-19

【中文标题】通过 URL 从 JSON 数据中获取数据并使用列表视图或回收器视图将其显示在 android 应用程序中

【英文标题】：fetch the data from JSON data through URL and displaying it in android app using list view or recycler view

【发布时间】：2020-05-19 03:37:02

【问题描述】：

我想在没有任何第三方库（如 Volley、Retrofit 等）的情况下显示 JSON URL 中存在的总数据。但我无法获取完整数据并将其显示在应用程序中，我只能显示对象。我的要求是调用我无法做到的每个数组及其内部对象。请帮助我，任何人。

-------XML 代码---

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_
    android:layout_
    tools:context=".MainActivity">

    <Button
        android:layout_
        android:layout_
        android:text="Click Me"
        android:layout_marginBottom="10dp"
        android:id="@+id/button"/>


    <ScrollView
        android:layout_
        android:layout_
        android:layout_below="@+id/button">
        <TextView
            android:layout_
            android:layout_
            android:padding="5dp"
            android:textSize="24sp"
            android:id="@+id/fetcheddata"
            android:hint="Feteched Text Here"/>
    </ScrollView>


</RelativeLayout>

-------JSON数据-----

"Table":[

"Error_code":"0","Error_Message":"Success","EncryptionFlag":"N"

],

"Table1":[

"Fund_Id":"128","FN_FundDescription":"ABCD FUND","Fund_Id":"178","FN_FundDescription":"XYZ FUND","Fund_Id":"116","FN_FundDescription":"Pritham FUND","Fund_Id":"118","FN_FundDescription":"Ram FUND","Fund_Id":"130","FN_FundDescription":"Mannu FUND"]

-------FETCHED.JAVA------

public class fetchData extends AsyncTask<Void,Void,Void>

    String data="";
    String dataParsed="";
    String singleParsed="";
    @Override
    protected Void doInBackground(Void... voids)
    
        try
        
            URL url=new URL("https://api.myjson.com/bins/baobi");
            HttpURLConnection httpURLConnection= (HttpURLConnection) url.openConnection();
            InputStream inputStream = httpURLConnection.getInputStream();
            BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(inputStream));
            String line="";
            while (line!=null)
            
                line=bufferedReader.readLine();
                data =data + line;
            
            JSONArray JA = new JSONArray(data);
            for (int i=0; i<JA.length();i++)
            
                JSONObject JO= (JSONObject) JA.get(i);
                singleParsed="Fund Id:" + JO.get("Fund_Id") +"\n" +
                             "Fund Description:" + JO.get("FN_FundDescription") +"\n";
                dataParsed = dataParsed + singleParsed + "\n";
            
        
        catch (MalformedURLException e)
        
            e.printStackTrace();
        
        catch (IOException e)
        
            e.printStackTrace();
        
        catch (JSONException e)
        
            e.printStackTrace();
        
        return null;
    
    @Override
    protected void onPostExecute(Void aVoid)
    
        super.onPostExecute(aVoid);
        MainActivity.data.setText(this.dataParsed);
    

-----主要活动.JAVA-----

public class MainActivity extends AppCompatActivity

    Button click;
    public static TextView data;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        click=findViewById(R.id.button);
        data=(TextView)findViewById(R.id.fetcheddata);
        click.setOnClickListener(new View.OnClickListener()
        
            @Override
            public void onClick(View v)
            
                fetchData process=new fetchData();
                process.execute();
            
        );
    

【问题讨论】：

使用这个 runOnUiThread(new Runnable() @Override public void run() );

执行后

您遇到任何错误？

就像@Varun Raj 建议的那样，加上使用 Recyclerview 列出来自 array 的数据会更好。这些是 youtube 和博客中的大量教程。

我没有收到任何错误，问题是我想通过调用它的数组名称和它有很多数组来显示 json 对象，我没有得到

【参考方案1】：

试试这个，它适用于当前响应

     public class fetchData extends AsyncTask<Void,Void,String>

    String data="";
    String dataParsed="";
    String singleParsed="";
    @Override
    protected String doInBackground(Void... voids)
    
        try
        
            URL url=new URL("https://api.myjson.com/bins/baobi");
            HttpURLConnection httpURLConnection= (HttpURLConnection) url.openConnection();
            InputStream inputStream = httpURLConnection.getInputStream();
            BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(inputStream));
            String line="";
            while (line!=null)
            
                line=bufferedReader.readLine();
                data =data + line;
            
            JSONObject object = new JSONObject(data);
            JSONArray JA=object.optJSONArray("Table1");
            JSONArray Error=object.optJSONArray("Table");

            for (int i=0; i<JA.length();i++)
            
                JSONObject JO= (JSONObject) JA.get(i);
                singleParsed="Fund Id:" + JO.get("Fund_Id") +"\n" +
                        "Fund Description:" + JO.get("FN_FundDescription") +"\n";
                dataParsed = dataParsed + singleParsed + "\n";

            
            for (int j=0; j<Error.length();j++)
            
                JSONObject JO= (JSONObject) Error.get(j);
                singleParsed="Error_code:" + JO.get("Error_code") +"\n" +
                        "Error_Message:" + JO.get("Error_Message") +"\n"+
                        "EncryptionFlag:" + JO.get("EncryptionFlag") +"\n";
                dataParsed = dataParsed + singleParsed + "\n";

            
            return dataParsed;
        
        catch (MalformedURLException e)
        
            e.printStackTrace();
         catch (IOException e)
        
            e.printStackTrace();
        
        catch (JSONException e)
        
            e.printStackTrace();
        
        return null;
    
    @Override
    protected void onPostExecute(String aVoid)
    
        super.onPostExecute(aVoid);
        Log.e("data asyc",dataParsed+"");
    

onPostExecute 我有打印日志，在我的情况下输出是

数据异步：

Fund Id:128
Fund Description:ABCD FUND

Fund Id:178
Fund Description:XYZ FUND

Fund Id:116
Fund Description:Pritham FUND

Fund Id:118
Fund Description:Ram FUND

Fund Id:130
Fund Description:Mannu FUND

Error_code:0
Error_Message:Success
EncryptionFlag:N

【讨论】：

但在你的情况下，我得到相同的旧输出，我希望“表”数组对象也与表 2 一起显示

是的兄弟其实也是数据之一

请推荐我的答案以供审核