Develop Reference

How to Save "Data.Json" file from assets to internal Storage and then use it for read/write

Currently i am fetching a package details(Onnet Minutes, Offnet Minutes, etc) from a Json file "Data.json" from assets but i know we cannot change values from assets. So my Question is how to copy Data.json to internal storage and then Load it for read/Write.
I am using this to load Data.Json from Assets
public String loadJSONFromAsset() {
String json = null;
try {
InputStream is = getAssets().open("Data.json");
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
is.close();
json = new String(buffer, "UTF-8");
Toast.makeText(jazz_sim_lagao_offer_details.this, "JSON Loaded", Toast.LENGTH_SHORT).show();
} catch (IOException ex) {
ex.printStackTrace();
return null;
}
return json;
}
and using this code to update data
private void UpdateData() {
JSONObject JSONobj = null;
try {
loadJSONFromAsset();
//get JSONObject from JSON file
JSONobj = new JSONObject(loadJSONFromAsset());
//fetch JSONObject named
JSONObject Jazz_SimLagaoOffer = JSONobj.getJSONObject("packages").getJSONObject("jazz_packages").getJSONObject("call_packages").getJSONObject("sim_lagao_offer");
String Jazz_SimLagaoOffer_ONNET = Jazz_SimLagaoOffer.getString("onnet");
Jazz_SimLagaoOffer_OnNet_TextView.setText(Jazz_SimLagaoOffer_ONNET);
String Jazz_SimLagaoOffer_OFFNET = Jazz_SimLagaoOffer.getString("offnet");
Jazz_SimLagaoOffer_OffNet_TextView.setText(Jazz_SimLagaoOffer_OFFNET);
String Jazz_SimLagaoOffer_MBs = Jazz_SimLagaoOffer.getString("mbs");
Jazz_SimLagaoOffer_Mb_TextView.setText(Jazz_SimLagaoOffer_MBs);
String Jazz_SimLagaoOffer_SMS = Jazz_SimLagaoOffer.getString("sms");
Jazz_SimLagaoOffer_Sms_TextView.setText(Jazz_SimLagaoOffer_SMS);
String Jazz_SimLagaoOffer_SUBCODE = Jazz_SimLagaoOffer.getString("sub_code");
Jazz_SimLagaoOffer_Sub_Code_TextView.setText(Jazz_SimLagaoOffer_SUBCODE);
String Jazz_SimLagaoOffer_CHECKCODE = Jazz_SimLagaoOffer.getString("check_code");
Jazz_SimLagaoOffer_Check_Code_TextView.setText(Jazz_SimLagaoOffer_CHECKCODE);
String Jazz_SimLagaoOffer_UNSUBCODE = Jazz_SimLagaoOffer.getString("unsub_code");
Jazz_SimLagaoOffer_Unsub_Code_TextView.setText(Jazz_SimLagaoOffer_UNSUBCODE);
Jazz_SimLagaoOffer_Charges = Jazz_SimLagaoOffer.getString("charges");
} catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getBaseContext(), JSONobj + "", Toast.LENGTH_SHORT).show();
}
}
How to Get Json Object?
Here is My Data.Json
{
"packages" : {
"jazz_packages" : {
"call_packages" : {
"sim_lagao_offer" : {
"charges" : "0.01",
"check_code" : "*551*2#",
"mbs" : "1500",
"offnet" : "5000",
"onnet" : "3000",
"sms" : "3000",
"sub_code" : "*551#",
"unsub_code" : "*551*3#"
}
}
}
}
}

Try this
private void CopyAssets() {
AssetManager assetManager = getAssets();
String[] files = null;
System.out.println("File name => "+filename);
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open(YOUR_ASSETS_FILE); // if files resides inside the "Files" directory itself
out = new FileOutputStream(STORAGE_PATH).toString() +"/" + filename);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch(Exception e) {
e.printStackTrace();
}
}
private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
}
}
Use below code to read from storage
String jsongString = readFromFile();
JSONObject mainJsonObject = new JSONObject(jsongString);
JSONObject Jazz_SimLagaoOffer = mainJsonObject.getJSONObject("packages").getJSONObject("jazz_packages").getJSONObject("call_packages").getJSONObject("sim_lagao_offer");
Use below method to read data from internal storage file and return as String.
private String readFromFile() {
String ret = "";
InputStream inputStream = null;
try {
inputStream = openFileInput("names.json");
if ( inputStream != null ) {
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
String receiveString = "";
StringBuilder stringBuilder = new StringBuilder();
while ( (receiveString = bufferedReader.readLine()) != null ) {
stringBuilder.append(receiveString);
}
ret = stringBuilder.toString();
}
}
catch (FileNotFoundException e) {
Log.e("login activity", "File not found: " + e.toString());
} catch (IOException e) {
Log.e("login activity", "Can not read file: " + e.toString());
}
finally {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return ret;
}
Hope this work :)

I Got Answer my own Question after 1 Day Research and Thanks to #pratik vekariya
helped me a lot.
CopyAssets() works perfect as defined #pratik vekariya in his answer and to readfromfile see my Question loadJSONFromAssets()
and i Just replaced line
InputStream is = getAssets().open("Data.json");
with this
InputStream is = new FileInputStream(getFilesDir().toString() +"/" + "Data.json");
to to load .json file from files and get json object from inputStrem

Why can't i see my JSON question in my text view?

For a feedback app, I need to display a different question with multiple posibility-answers a day, from a Json File that has an array of questions, the questions have to be randomly displayed on the screen, one a day. I loaded the file from Assets, everything works fine butt the question won't appear. Below is my Java Code, could someone help me?
try {
readJson();
} catch (JSONException e) {
e.printStackTrace();
}
}
private void readJson() throws JSONException {
String qaJSONString = loadFileFromAssets("QA.json");
System.out.print(qaJSONString);
JSONObject jsonObject = new JSONObject(qaJSONString);
JSONArray jsonArray = jsonObject.getJSONArray("KalenderTag");
JSONObject montag = jsonArray.getJSONObject(0);
TextView textView = (TextView) findViewById(R.id.text_View_result);
// Umfrage umfrage1 = new Umfrage(montagJSON.getString("Frage"));
// textView.setText(umfrage1.getFrage());
}
private String loadFileFromAssets(String filename) {
String tContents = "";
try {
InputStream stream = getAssets().open(filename);
int size = stream.available();
byte[] buffer = new byte[size];
stream.read(buffer);
stream.close();
tContents = new String(buffer);
} catch (IOException e) {
System.out.print("Json could not be parsed to string!");
}
return tContents;
}

How to convert a string to JSON?

I'm using volley to get a file from the internet, the file is an array. I'm saving the file in cache to do this I have to convert the file into a string. I have a function that reads the cache and pass the response to another file to display
the information, but when i'm trying to convert the resoionse back to an array i get an error
Value AuthStatus of type java.lang.String cannot be converted to JSONObject
I'm really new on android, hoping someone can point me on the right direction
private void cacheFile(JSONObject response) {
JSONObject res = response;
String filename = "jsonfile";
FileOutputStream outputStream;
try {
outputStream = openFileOutput(filename, Context.MODE_PRIVATE);
outputStream.write(res.toString().getBytes("utf-8"));
outputStream.close();
Log.e(TAG, "Bien");
} catch (Exception e) {
e.printStackTrace();
}
}
private void readCache(String filename) {
FileInputStream inputStream;
try {
inputStream = openFileInput(filename);
inputStream.read();
String body = IOUtils.toString(inputStream, StandardCharsets.UTF_8.name());
inputStream.close();
fromCache(body);
} catch (Exception e) {
e.printStackTrace();
}
}
public void fromCache(String json) {
JSONObject jsonObject = null;
try {
jsonObject = new JSONObject(json);
JSONArray jsonArray = jsonObject.getJSONArray("cars");
Log.e(TAG, "Array Size: " + jsonArray.length());
} catch (JSONException e) {
e.printStackTrace();
}
}

You have to use JSONValue.parse method as shown below:
public void fromCache(String json) {
JSONObject jsonObject = null;
try {
jsonObject = (JSONObject)JSONValue.parse(json);
JSONArray jsonArray = jsonObject.getJSONArray("cars");
Log.e(TAG, "Array Size: " + jsonArray.length());
} catch (JSONException e) {
e.printStackTrace();
}
}

Extract value from Json using Gson

I am trying to extract values from JSON from the URL provided below using GSON java library:
http://api.wunderground.com/api/b28d047ca410515a/forecast/q/-33.912,151.013.json
I have successfully used the code provided below to extract data from URL below:
http://api.wunderground.com/api/b28d047ca410515a/conditions/q/-33.912,151.013.json
Code:
String url = "http://api.wunderground.com/api/b28d047ca410515a/conditions/q/-33.912,151.013.json";
String url2 = "http://api.wunderground.com/api/b28d047ca410515a/forecast/q/-33.912,151.013.json";
InputStream is = null;
try {
is = new URL(url).openStream();
BufferedReader rd = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
String jsonText = readAll(rd);
JsonElement je = new JsonParser().parse(jsonText);
System.out.println("Current Temperature:" + getAtPath(je, "current_observation/temp_c").getAsString() );
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (is != null)
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
However I am getting exception trying to extract from url2 as per code below , it seems to be a more complicated json to get values from, any help please?
// below code not working
weather_icon_url = getAtPath(je, "current_observation/icon_url").getAsString();
is = new URL(url2).openStream();
BufferedReader rd2 = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
String jsonText2 = readAll(rd2);
JsonElement je2 = new JsonParser().parse(jsonText2);
System.out.println("max Temperature:" + getAtPath(je2, "forecast/simpleforecast/forecastday/high/celsius").getAsString() );
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (is != null)
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
getAtPath code:
private static JsonElement getAtPath(JsonElement e, String path) {
JsonElement current = e;
String ss[] = path.split("/");
for (int i = 0; i < ss.length; i++) {
current = current.getAsJsonObject().get(ss[i]);
}
return current;
}

The problem you are facing is because there is an issue with the getAtPath implementation.
[{"date":{"epoch":"1459152000"... represents a JSONArray which the method is trying to access as JSONObject. Hence the IllegalStateException.
JsonObject com.google.gson.JsonElement.getAsJsonObject()
convenience method to get this element as a JsonObject. If the element
is of some other type, a IllegalStateException will result. Hence it
is best to use this method after ensuring that this element is of the
desired type by calling isJsonObject() first.
You can update and use something like below, as of now it returns only the first element.
private static JsonElement getAtPath(JsonElement e, String path) {
JsonElement current = e;
String ss[] = path.split("/");
for (int i = 0; i < ss.length; i++) {
if(current instanceof JsonObject){
current = current.getAsJsonObject().get(ss[i]);
} else if(current instanceof JsonArray){
JsonElement jsonElement = current.getAsJsonArray().get(0);
current = jsonElement.getAsJsonObject().get(ss[i]);
}
}
return current;
}

This should work:
System.out.println("max Temperature:" + getAtPath(je2, "forecast/simpleforecast/forecastday/high/celsius").getAsString() );

How to pass string in android without error- A resource was acquired at attached stack trace but never released-

I try to fetch stringBuilder object to the my main activity. I check my json file or parsing codes they works well. However when I try to fetch stringbuilder it gave an error:
A resource was acquired at attached stack trace but never released. See java.io.Closeable for information on avoiding resource leaks.
java.lang.Throwable: Explicit termination method 'close' not called
code for Server.java is as below
`
public class Server extends Activity {
static StringBuilder stringBuilder = new StringBuilder();
public Server(){
try {
JSONObject obj = new JSONObject(loadJSONFromAsset());
JSONArray project = obj.getJSONArray("project");
for (int i = 0; i < project.length(); i++) {
JSONObject ss = project.getJSONObject(i);
stringBuilder.append(ss.getString("title") + "\n");
JSONArray post = ss.getJSONArray("posts");
for(int j = 0; j < post.length();j++){
JSONObject posts = post.getJSONObject(j);
stringBuilder.append(posts.getString("id") +"\n");
JSONArray tag = posts.getJSONArray("tags");
for(int k = 0; k < tag.length();k++){
stringBuilder.append(tag.getString(k) +"\n");
}
}
}
}
catch (JSONException e) {
stringBuilder.append("error");
e.printStackTrace();
}
}
public String getString(){
return stringBuilder.toString();
}
public String loadJSONFromAsset() {
String json = null;
try {
InputStream is = getAssets().open("cat.json");
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
is.close();
json = new String(buffer, "UTF-8");
} catch (IOException ex) {
ex.printStackTrace();
return null;
}
return json;
}}
and here is my MainActivity.java
public class MainActivity extends Activity {
TextView jsonDataTextView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
jsonDataTextView = (TextView) findViewById(R.id.textView);
Server s = new Server();
jsonDataTextView.setText(s.stringBuilder.toString());} }
Is there any solution?

The InputStream may not be closed in the try block of your loadJSONFromAsset method, and it should.
public String loadJSONFromAsset() {
String json = null;
InputStream is = null;
try {
is = getAssets().open("cat.json");
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
json = new String(buffer, "UTF-8");
}
catch (IOException ex) {
ex.printStackTrace();
}
finally {
if (is != null) {
try {
is.close();
}
catch (IOException ex) {
// Do you want to handle this exception?
}
}
}
return json;
}
Note: Something bothers me in your Server constructor, in the catch block you try to append "error" to your StringBuilder. Do you know that here, the StringBuilder may not be empty. Indeed in the try block, one (or more) attempt(s) to append some string to it may work before something goes wrong at some point.
Note 2: Server as a non Activity
public class Server {
private Context mContext;
public Server(Context context) {
mContext = context;
...
}
...
public String loadJSONFromAsset() {
...
mContext.getAssets().open("cat.json");
}
}
then in your MainActivity
Server s = new Server(this);