ParseMockJson

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;


public class ParseMockJson {
    public static String readFromfile(String filename) {
        StringBuilder returnString = new StringBuilder();
        InputStream fIn = null;
        InputStreamReader isr = null;
        BufferedReader input = null;
        try {
            fIn = SessionData.getContext().getResources().getAssets().open(filename);
            isr = new InputStreamReader(fIn);
            input = new BufferedReader(isr);
            String line = "";
            while ((line = input.readLine()) != null) {
                returnString.append(line);
            }
        } catch (Exception e) {
            e.getMessage();
        } finally {
            try {
                if (isr != null)
                    isr.close();
                if (fIn != null)
                    fIn.close();
                if (input != null)
                    input.close();
            } catch (Exception e2) {
                e2.getMessage();
            }
        }
        return returnString.toString();
    }
}

parseUtil.java

String str = ReadFromfile();
        Gson gson = new Gson();
        Forms form = gson.fromJson(str, Forms.class);
        onFormSuccess(form);






public String ReadFromfile(){
        StringBuilder returnString = new StringBuilder();
        InputStream fIn = null;
        InputStreamReader isr = null;
        BufferedReader input = null;
        try {
            fIn = AppContext.getInstance().getContext().getResources().getAssets() .open("updatecreditcards.json");
            isr = new InputStreamReader(fIn);
            input = new BufferedReader(isr);
            String line = "";
            while ((line = input.readLine()) != null) {
                returnString.append(line);
            }
        } catch (Exception e) {
            e.getMessage();
        } finally {
            try {
                if (isr != null)
                    isr.close();
                if (fIn != null)
                    fIn.close();
                if (input != null)
                    input.close();
            } catch (Exception e2) {
                e2.getMessage();
            }
        }
        return returnString.toString();
    }