Unable to read JSON file in android

Question

The following is the code I am using to read a JSON file stored in assets folder.

public class ReadJson extends Activity {
public String loadJSONFromAsset() {
    String json1 = null;
    try {

        InputStream is = getAssets().open("jsonfile1.json");
        int size = is.available();
        byte[] buffer = new byte[size];
        is.read(buffer);
        is.close();
        json1 = new String(buffer, "UTF-8");
    } catch (IOException ex) {
        ex.printStackTrace();
        return null;
    }
    return json1;
} 
}

The app crashes and shows

"Attempt to invoke virtual method 'android.content.res.AssetManager android.content.Context.getAssets()' on a null object reference" exception.

How to resolve this?

Make sure you are calling loadJSON after Activity is created. Or getApplicationContext.getAssets() — X3Btel, Aug 11 '16 at 09:44
see this: http://stackoverflow.com/questions/9544737/read-file-from-assets — DysaniazzZ, Aug 11 '16 at 09:45

score 0 · Answer 1 · answered Aug 11 '16 at 09:43

try this code:

BufferedReader reader = null;
try {
reader = new BufferedReader(
    new InputStreamReader(getAssets().open("jsonfile1.json")));

// do reading, usually loop until end of file reading  
String mLine;
while ((mLine = reader.readLine()) != null) {
   //process line
   ...
}
} catch (IOException e) {
//log the exception
} finally {
if (reader != null) {
     try {
         reader.close();
     } catch (IOException e) {
         //log the exception
     }
 }
 }

make sure your file path is exist or not

Md Sufi Khan · Answer 2 · 2016-08-11T09:52:28.763

0

You may try something like below.

try{
    StringBuilder buf=new StringBuilder();
    InputStream json = getAssets().open("jsonfile1.json");
    BufferedReader in = new BufferedReader(new InputStreamReader(json, "UTF-8"));
    String str;

    while ((str=in.readLine()) != null) {
      buf.append(str);
    }

    in.close();
} catch(Exception e){

}

Make sure your jsonfile1.json is a file of assets folder.

edited Aug 11 '16 at 09:52

answered Aug 11 '16 at 09:46

Md Sufi Khan

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score 0 · Answer 3 · answered Aug 11 '16 at 09:58

When are you calling loadJSONFromAsset()? It seems like you are calling it before the Activity is created. Try the following:

public class ReadJson extends Activity {

    @Override
    protected void onCreate(Bundle savedInstaceState) {
        super.onCreate(savedInstaceState);
        loadJSONFromAsset(); // call after super.onCreate()!!!!
        /// ...
    }

}

Unable to read JSON file in android

3 Answers3