How to Convert a JSON Array to a Java List for Android ListView?

Converting JSON Array to Java List for Android ListView

Android ListView, a commonly used component for displaying data, requires Java objects as its data source. However, API responses or data returned from servers are often in the form of JSON (JavaScript Object Notation), which contains arrays or lists of data. To render this data in a ListView, it's necessary to convert the JSON array into a Java list.

Here's how to achieve this conversion in Java for Android:

<code class="java">import org.json.JSONArray;
import org.json.JSONObject;

import java.util.ArrayList;

...

// Instantiate an ArrayList to store the converted data
ArrayList<String> list = new ArrayList<>();

// Get the JSON array from the JSON object
JSONArray jsonArray = (JSONArray) jsonObject;

// Check if the JSON array is not null
if (jsonArray != null) {
    // Get the length of the JSON array
    int len = jsonArray.length();

    // Iterate over the JSON array and add each element to the ArrayList
    for (int i = 0; i < len; i++) {
        list.add(jsonArray.get(i).toString());
    }
}</code>

In this code snippet:

• The JSON response is stored in a JSONObject variable.
• We extract the JSON array from the JSONObject using the (JSONArray) cast.
• We ensure that the JSON array is not null before iterating over it.
• We loop through the JSON array, converting each element to a String using jsonArray.get(i).toString() and adding it to the ArrayList.

Once the loop completes, the ArrayList contains the data from the JSON array, which can be used as the data source for the ListView.

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