How to iterate a JSON Array in Android?

AndroidApps/ApplicationsMobile Development

This example demonstrates how do I iterate JSON Array in android.

Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:padding="8dp"
   tools:context=".MainActivity">
   <TextView
      android:id="@+id/textView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:textSize="16sp"
      android:textStyle="bold" />
</RelativeLayout>

Step 3 − Add the following code to src/MainActivity.java

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class MainActivity extends AppCompatActivity {
   TextView textView;
   String strJson = "{ \"Employee\" :[{\"ID\":\"01\",\"Name\":\"Sam\",\"Salary\":\"50000\"},"
      + "{\"ID\":\"02\",\"Name\":\"Shankar\",\"Salary\":\"60000\"}] }";
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      textView = findViewById(R.id.textView);
      StringBuilder data = new StringBuilder();
      try {
         JSONObject jsonRootObject = new JSONObject(strJson);
         JSONArray jsonArray = jsonRootObject.optJSONArray("Employee");
         for (int i = 0; i < jsonArray.length(); i++) {
            JSONObject jsonObject = jsonArray.getJSONObject(i);
            int id = Integer.parseInt(jsonObject.optString("ID"));
            String name = jsonObject.optString("Name");
            float salary = Float.parseFloat(jsonObject.optString("Salary"));
            data.append("Employee ").append(i).append(" : \n ID= ")
               .append(id).append(" \n " + "Name= ")
               .append(name).append(" \n Salary= ")
               .append(salary).append(" \n\n ");
         }
         textView.setText(data.toString());
      }
      catch (JSONException e) {
         e.printStackTrace();
      }
   }
}

Step 4 − Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample">
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from the android studio, open one of your project's activity files and click Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −

Click here to download the project code.

raja
Published on 21-Nov-2019 10:32:47
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