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My Constructor for the filepath ist not working, JAVA

If I use the filepath directly in the class CtoJ it works.
If i pass it through the constructor it gives me a Nullpointer.
Well I do not know what I could add to make my problem any more clear.
Well if I use String path =""; it throws no such file or directory.
It seems like the constructor is not able to write the filepath into the path variable?
public class CSVReader {
public static void main(String[] args) {
CtoJ test = new CtoJ("/Users/peterg/Desktop/test.csv");
}
}
import org.json.CDL;
import org.json.JSONArray;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class CtoJ {
private String path;
private StringBuilder content = new StringBuilder();
private String line;
private String stringtoJSON;
public CtoJ(String path) {
this.path = path;
}
{
try {
BufferedReader reader = new BufferedReader(new FileReader(path));
while ((line = reader.readLine()) != null) {
content.append(removeUnnecessaryQuotes(line));
content.append(System.lineSeparator());
}
stringtoJSON = content.toString();
JSONArray jsonArray = CDL.toJSONArray(stringtoJSON);
System.out.println(jsonArray);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static String removeUnnecessaryQuotes(String s) {
String withoutQuotes;
withoutQuotes = s.substring(0).replaceAll("\"", "");
withoutQuotes.substring(0).replaceAll("\"\"", "\"");
return withoutQuotes;
}
}
Here is some of the data I use, if u want to test it:
FID,OBJECTID,SHAPE,LAGE,GRILLPLATZ_ID,RESERVIERUNG,WEBLINK1,SE_ANNO_CAD_DAT
"GRILLPLATZOGD.6748,6748,POINT (16.465255884594104 48.19018769574157),""22., Donauinsel, ca. 350 Meter stromab der Steinspornbrücke (Inselmitte, Erdwall)"",15,ja,http://www.wien.gv.at/amtshelfer/umwelt/wasserbau/donauinsel/grillplatzreservierung.html,"
"GRILLPLATZOGD.6749,6749,POINT (16.48177464603615 48.183356069714286),""22., Neue Donau, linkes Ufer, zwischen Steinspornbrücke und Waluliso Brücke (bei km 5,1) (Dammbereich) "",16,ja,http://www.wien.gv.at/amtshelfer/umwelt/wasserbau/donauinsel/grillplatzreservierung.html,"
"GRILLPLATZOGD.6750,6750,POINT (16.460158556964053 48.177745677669925),""11., Donaukanal, Alberner Hafenzufahrtsstraße, Nähe Margetinstraße"",0,nein,http://www.wien.gv.at/umwelt/wald/freizeit/grillen/,"

you get the error because you accidentally used an instance initializer block in your Code. That is
class Foo {
//constructor
public Foo() {
System.out.println("Constructor");
}
//instance initializer Block
{
System.out.println("Instance Initializer");
}
}
Generally, this is okay, however, the initializer block is executed before the constructor is.
In your particular example
BufferedReader reader = new BufferedReader(new FileReader(path));
in the initializer block is dependent on the instantiation of path in the constructor. So as a quick fix just move the code from the initializer to the constructor and you shouldn't get any NullPointerException.

read JSON from url on JavaFX controller does not update when JSON updated

I try to create java program that read JSON from this url, the url contain JSON array that updated every 20 seconds here is my java program that listen to the url and print the last JSON object from the JSON file:
ListenTojson.java
package com.company;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.*;
import java.net.URL;
import java.nio.charset.Charset;
class ListenToJson implements Runnable {
public void run() {
long tenSeconds = 10*1000L;
while(true) {
try {
JSONArray json = readJsonFromUrl("http://frozen-brook-16337.herokuapp.com/history.json");
JSONObject jo=json.getJSONObject(json.length()-1);
System.out.println(jo.get("data"));
Thread.sleep(tenSeconds);
} catch (InterruptedException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private static String readAll(Reader rd) throws IOException {
StringBuilder sb = new StringBuilder();
int cp;
while ((cp = rd.read()) != -1) {
sb.append((char) cp);
}
return sb.toString();
}
public static JSONArray readJsonFromUrl(String url) throws IOException, JSONException {
InputStream is = new URL(url).openStream();
try {
BufferedReader rd = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
String jsonText = readAll(rd);
JSONArray jsonArray = new JSONArray(jsonText);
return jsonArray;
} finally {
is.close();
}
}
}
Main.java
package com.company;
public class Main {
public static void main(String[] args){
(new Thread(new ListenToJson())).start();
}
}
The code run as I expected. The JSON file contains coordinate that keep updated every 10 seconds. I need to create map application that read the coordinate from the JSON and then show it on the map as marker, I use JavaFx library to create the map application, when I add the code above (ListenToJson.java) the program behave differently when I use JavaFX library it does not read the latest JSON file.
here is the code
public class Controller{
//some code
(new Thread(new ListenToJson())).start();
//some code
}
Controller.java
The full class that I try to update the UI using the ListenToJson() function is here https://github.com/kikirizki/mapapp/blob/master/src/main/java/com/delameta/vesselmap/Controller.java the line 526, thanks
whats wrong with my code, why the ListenToJson() function read the outdated JSON file ?

I found the solution myself, the problem is the mapjfx library (I use in the code) use cache to cache the map tile and then it cause to cache the JSON file too. The solution is simply disable the cache mechanism, just diable it at line 350, change
offlineCache.setActive(true);
to be
offlineCache.setActive(false);

java.lang.String cannot be cast to org.json.simple.JSONObject simple-json

I am getting strange problem while trying to parse a simple json using simple-json by google.
Here is my code which is not working:
String s = args[0].toString();
JSONObject json = (JSONObject)new JSONParser().parse(s);
When I execute, it will give me the exception java.lang.String cannot be cast to org.json.simple.JSONObject
But when I hard code json directly like below its working fine. Wat could be the reason?
JSONObject json = (JSONObject)new JSONParser().parse("{\"application\":\"admin\",\"keytype\":\"PRODUCTION\",\"callbackUrl\":\"qwerewqr;ewqrwerq;qwerqwerq\",\"authorizedDomains\":\"ALL\",\"validityTime\":\"3600000\",\"retryAfterFailure\":true}");
UPDATE
When I print s, it will give me the output below:
"{\"application\":\"admin\",\"keytype\":\"PRODUCTION\",\"callbackUrl\":\"qwerewqr;ewqrwerq;qwerqwerq\",\"authorizedDomains\":\"ALL\",\"validityTime\":\"3600000\",\"retryAfterFailure\":true}"

I ran this through eclipse by providing arguments in run configuration.
public static void main(String[] args) {
String s = args[0].toString();
System.out.println("=>" + s);
try {
JSONObject json = (JSONObject) new JSONParser().parse(s);
System.out.println(json);
} catch (ParseException e) {
e.printStackTrace();
}
}
Output
=>{"application":"admin","keytype":"PRODUCTION","callbackUrl":"qwerewqr;ewqrwerq;qwerqwerq","authorizedDomains":"ALL","validityTime":"3600000","retryAfterFailure":true}
{"validityTime":"3600000","callbackUrl":"qwerewqr;ewqrwerq;qwerqwerq","application":"admin","retryAfterFailure":true,"authorizedDomains":"ALL","keytype":"PRODUCTION"}

Make sure that the string is a valid JSON. You can user JSONObject parameterized constructor with the given string to convert the JSON string to a valid JSON object.
For example,
try {
String jsonString = " {'application':'admin','keytype':'PRODUCTION','callbackUrl':'qwerewqr;ewqrwerq;qwerqwerq','authorizedDomains':'ALL','validityTime':3600000,'retryAfterFailure':true}";
JSONObject data = new JSONObject(jsonString);
String application = data.getString("application"); //gives admin
String keytype = data.getString("keytype"); //gives PRODUCTION
} catch (JSONException e) {
e.printStackTrace();
}

I had the same issue
package com.test;
import org.json.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
public class JSONTest {
public static void main(String[] args) {
String s = args[0];
try {
JSONObject json = new JSONObject((String) new JSONParser().parse(s));
System.out.println(json);
} catch (ParseException e) {
e.printStackTrace();
}
}
}
This worked for me

Try this
package com.test;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
public class JSONTest {
public static void main(String[] args) {
String s = args[0];
try {
JSONObject json = (JSONObject) new JSONParser().parse(s);
System.out.println(json);
} catch (ParseException e) {
e.printStackTrace();
}
}
Then on command line
java -classpath ".;json-simple-1.1.1.jar" com.test.JSONTest {\"application\":\"admin\",\"keytype\":\"PRODUCTION\",\"callbackUrl\":\"qwerewqr;ewqrwerq;qwerqwerq\",\"authorizedDomains\":\"ALL\",\"validityTime\":\"3600000\",\"retryAfterFailure\":true}
The out put is
{"validityTime":"3600000","callbackUrl":"qwerewqr;ewqrwerq;qwerqwerq","application":"admin","retryAfterFailure":true,"authorizedDomains":"ALL","keytype":"PRODUCTION"}

Calling a Jsonreader class for twitch streams

Ive encountered a little problem.
I made a json url checker that checks if a twitch.tv stream is either online or offline.
That one thing is handled in a seperate class TwitchLiveChecker.java.
Now i want to call that class with a timer all X minutes but somehow i dont understand how to call the class.
This is how i call it;
public void LiveChecker() {
TTtwl.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
try {
TwitchLiveChecker.startup(); *<- THIS Doesnt work :(*
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(TwitchLiveChecker.json);
System.out.println(TwitchLiveChecker.json);
}
}, 1000*10, 1000*10);
}
and this is my TwitchLiveChecker class File;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.nio.charset.Charset;
import org.json.JSONException;
import org.json.JSONObject;
public class TwitchLiveChecker {
public static JSONObject json;
private static String readAll(Reader rd) throws IOException {
StringBuilder sb = new StringBuilder();
int cp;
while ((cp = rd.read()) != -1) {
sb.append((char) cp);
}
return sb.toString();
}
public static JSONObject readJsonFromUrl(String url) throws IOException, JSONException {
InputStream is = new URL(url).openStream();
try {
BufferedReader rd = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
String jsonText = readAll(rd);
JSONObject json = new JSONObject(jsonText);
return json;
} finally {
is.close();
}
}
public static void startup(String[] args) throws IOException, JSONException {
json = readJsonFromUrl("http://api.justin.tv/api/stream/list.json?channel="+MyBot.ownerchannel+"");
System.out.println(json.toString());
System.out.println(json.get("id"));
}
}
Im thankful for any hints or examples on what im doing wrong :D

You are not passing parameters to a method that requires them. Since TwitchLiveChecker.startup() doesn't use the args parameter, you should remove it. Your method signature should be public static void startup(), not public static void startup(String[] args)
Also, threads and static data (specifically your public static JSONObject json; don't mix well. Depending on what your thread pool is doing, you could have multiple threads writing to your static json object at the same time, corrupting the data in it.

Correct syntax for inputing a String file into a 2D Array?

What is the correct syntax for creating a 2D array from a text file? This array must be string not char or int. None of the information I've found on this is for string, and I haven't been able to figure the exact syntax out myself.

You can use ArrayList object .Its internal implemetation is Resizable or growable array.
So you can achieve your requirement by ArrayList<String>.You can get even arry by using its utility methods.
For more details ArrayList docs
For sample click here

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class Read2DimensionFileToList {
public static void main(String[] args) {
String [][] sList=new String[100][2];
BufferedReader br = null;
try {
String s;
br = new BufferedReader(new FileReader("C:\\testing.txt"));
int i=0;
while ((s = br.readLine()) != null) {
String []sArray=s.split(",");
sList[i++][0]=sArray[0];
sList[i][1]=sArray[1];
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (br != null)br.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}