Simple file reader for Android. Just add this file to your project!

SimpleFileReader.java

// PUT YOUR PACKAGE HERE
// package com.mycompany.myproduct;

import android.content.Context;
import org.json.JSONArray;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

/**
 * Created by Guido Lodetti on 17/05/2017.
 *
 * This static class allows you to read from a text file in the following formats: String, JSONObject, JSONArray.
 * If an error occurs, null is returned.
 *
 * Here are the available methods:
 *
 * String ->
 *   SimpleFileReader.stringFromFile(Context context, String path)
 *   SimpleFileReader.stringFromAsset(Context context, String name)
 *
 * JSONObject ->
 *   SimpleFileReader.jsonObjectFromFile(Context context, String path)
 *   SimpleFileReader.jsonObjectFromAsset(Context context, String name)
 *
 * JSONArray ->
 *   SimpleFileReader.jsonArrayFromFile(Context context, String path)
 *   SimpleFileReader.jsonArrayFromAsset(Context context, String name)
 *
 */

public class SimpleFileReader {
    private static String stringFromInputStream(InputStream is) {
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
            String contents = "";
            String line;
            while ((line = reader.readLine()) != null) {
                contents += line;
            }
            return contents;
        } catch (Exception ex) {}
        return null;
    }

    public static String stringFromAsset(Context context, String name) {
        try {
            return stringFromInputStream(context.getAssets().open(name));
        } catch (Exception ex) {}
        return null;
    }

    public static String stringFromFile(Context context, String path) {
        try {
            return stringFromInputStream(context.openFileInput(path));
        } catch (Exception ex) {}
        return null;
    }

    private static JSONObject jsonObjectFromString(String string) {
        if (string == null || string.length() == 0) return null;
        try {
            return new JSONObject(string);
        } catch (Exception ex) {}
        return null;
    }

    public static JSONObject jsonObjectFromFile(Context context, String path) {
        return jsonObjectFromString(stringFromFile(context, path));
    }

    public static JSONObject jsonObjectFromAsset(Context context, String name) {
        return jsonObjectFromString(stringFromAsset(context, name));
    }

    private static JSONArray jsonArrayFromString(String string) {
        if (string == null || string.length() == 0) return null;
        try {
            return new JSONArray(string);
        } catch (Exception ex) {}
        return null;
    }

    public static JSONArray jsonArrayFromFile(Context context, String path) {
        return jsonArrayFromString(stringFromFile(context, path));
    }

    public static JSONArray jsonArrayFromAsset(Context context, String name) {
        return jsonArrayFromString(stringFromAsset(context, name));
    }
}