I'm creating a Spring application on backend and my main goal is to manage properties (add/update/delete) in *.properties file. I want to convert this file to JSON and then manipulate it from UI application.
Is there any possibility to convert structure like this:
a.x=1
a.y=2
b.z=3
To JSON like this:
{
"a": {
"x": 1,
"y": 2
},
"b": {
"z": 3
}
}
I found solution to use GSON library, but it creates for me flat structure, not hierarchical, code I used:
Properties props = new Properties();
try (FileInputStream in = new FileInputStream(classPathResource.getFile())) {
props.load(in);
}
String json = new GsonBuilder().enableComplexMapKeySerialization().create().toJson(props);
Is here someone who was facing same problem and maybe found a working project for this? Maybe GSON library can do that?
This solution does involve loads of work, but you will get what you want to achieve using the below code, basically, the idea is to split the key based on the single dot and then create a JsonObject if the same first key is found.
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.Properties;
import org.json.JSONObject;
import com.fasterxml.jackson.annotation.JsonIgnore;
public class SOTest {
public static void main(String[] args) throws IOException {
JSONObject jsonObject = new JSONObject();
FileReader fileReader = new FileReader(new File("C:\\Usrc\\main\\java\\Sample.properties"));
Properties properties = new Properties();
properties.load(fileReader);
Iterator<Entry<Object, Object>> iterator = properties.entrySet().iterator();
while (iterator.hasNext()) {
Entry<Object, Object> entry = iterator.next();
String value = (String) entry.getKey();
String[] values = value.split("\\.");
JSONObject opt = jsonObject.optJSONObject(values[0]);
if(opt!=null) {
opt.put(values[1],entry.getValue());
}else {
JSONObject object = new JSONObject();
object.put(values[1], entry.getValue());
jsonObject.put(values[0], object);
}
}
System.out.println(jsonObject.toString());
}
}
Output
{"a":{"x":"1","y":"3"},"b":{"z":"10"}}
Related
I am struggling with this issue and I can't find an answer anywhere. Ihave a .jsonlist file formatted like this :
example.jsonlist
{"op_author":1, "op_name":2}
{"op_author":3, "op_name":4}
{"op_author":5, "op_name":6}
I would like to parse it into a Java object, but I can't find how to do it with Gson or json-simple libraries since it is not formated like a json object.
Here is what I tried so far :
Modele.java
public class Modele {
private String op_author, op_name;
}
JsonListToJava.java
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
public class JsonListToJava {
public static void main(String[] args) throws IOException {
try(Reader reader = new InputStreamReader(JsonListToJava.class.getResourceAsStream("example.jsonlist"), "UTF-8")){
Gson gson = new GsonBuilder().create();
Modele p = gson.fromJson(reader, Modele.class);
System.out.println(p);
}
}
}
But I get this error :
Exception in thread "main" com.google.gson.JsonSyntaxException:
com.google.gson.stream.MalformedJsonException: Use
JsonReader.setLenient(true) to accept malformed JSON at line 2 column ...
JSON libraries are usually designed to work with valid JSONs.
In your case you can read the file line by line, then parse:
try(BufferedReader reader = new BufferedReader(new InputStreamReader(JsonListToJava.class.getResourceAsStream("example.jsonlist"), "UTF-8"))){
Gson gson = new GsonBuilder().create();
Stream<String> lines = reader.lines();
lines.forEach((line) -> {
Model p = gson.fromJson(line, Model.class);
System.out.println(p);
});
}
Hi I am try to parse some JSON by GSON which used number as the key.
I reference the post but it give some error and I don't know why.
How to convert json objects with number as field key in Java?
I also see the post but still cannot solve my problem.
"Expected BEGIN_OBJECT but was STRING at line 1 column 1"
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Map;
public class Main {
public static void main(String[] args) {
Gson gson = new Gson();
Type type = new TypeToken<HashMap<String, HashMap<String, String>>>() {}.getType();
Map<String, Map<String, String>> map = gson.fromJson("./src/main/resources/input.json", type);
}
}
The json file is
{
"1":{"id":"1"}
}
The fromJson method doesn't receive a filename, it receives an actual JSON: look at the docs here
But there is an overload that receives a Reader instead:
try (FileReader reader = new FileReader("./src/main/resources/input.json"))
{
map = gson.fromJson(reader, type)
}
catch (...) { ... }
I'm new to JSON and GSON and as well as Java.
Currently I'm having difficulties on removing items in my Json files. Below are my code
public void removeUser() throws IOException{
File accounts = new File("accounts.json");
delete(accounts);
}
void delete(File acc) throws IOException {
if (acc.exists()) {
List userlist = new ArrayList();
Iterator<Users> iterator = userlist.iterator();
while (iterator.hasNext()) {
if (iterator.next().getUsername().equals(deleteTxt.getText())) {
iterator.remove();
notifications();
deleteTxt.setText(null);
notificationLbl.setText("Wish granted!");
break;
}
}
}
}
and for my json's file structure
{
"username": "admin",
"password": "21232f297a57a5a743894a0e4a801fc3",
"roles": "admin"
},
{
"username": "client",
"password": "21232f297a57a5a743894a0e4a801fc3",
"roles": "client"
}
Thing I wanted it to happen:
When I pressed deleteBtn, removeUser() will be executed and the users and the details will be removed.
Thing that's happen:
Nothing happen
Can anyone guide me on how to do remove?
sample code to read a jsonarray from a file , modify into a new array and store it back using apache-commons-io.jar
import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import org.apache.commons.io.FileUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public static void delete(String username) throws JSONException, IOException {
File file = new File("E:\\accounts.json");
String encoding = Charset.defaultCharset().toString();
JSONArray oldDataArray = new JSONArray(FileUtils.readFileToString(file, encoding));
System.out.println(oldDataArray);
JSONArray newDataArray = new JSONArray();
for(int n=0;n<oldDataArray.length();n++) {
JSONObject nthObject = oldDataArray.getJSONObject(n);
if(!username.equals(oldDataArray.getJSONObject(n).get("username"))) {
newDataArray.put(nthObject);
}
}
System.out.println(newDataArray);
FileUtils.writeStringToFile(file, newDataArray.toString(), encoding);
}
I have read the posts that appeared to be the same as my question but I must be missing something. My environment is Eclipse Mars. My JAVA is 1.7 and I have imported json-simple. I simply wish to parse the json that is returned from my web service. I control the web service if I need to modify its output. I see the json in arg[0] as noted below however the Object obj is null as of course is the JSONArray array. I know that I am missing something basic but I am stumped and a bit tired.
Here is the returned json:
[{"$id":"1","NumberID":121183,"PortfolioID":718,"PropertyID":14489,"Adsource":17287,"PlanTypeID":1,"GreetingFile":"HolidayGreeting.wav","PromptFile1":"senior.leasing.first.wav","Accepts1":2,"PromptAction_ID1":1,"PromptFile2":"Default.wav","Accepts2":2,"PromptAction_ID2":1,"PromptFile3":"Default.wav","Accepts3":2,"PromptAction_ID3":1,"PromptFile4":"Default.wav","Accepts4":2,"PromptAction_ID4":1,"PromptFile5":"Default.wav","Accepts5":2,"PromptAction_ID5":1,"HoldMsgFile1":"SpectrumHold.wav","HoldMsgFile2":"Default.wav","Destination1":15197,"Destination2":15024,"Destination3":0,"UIType_ID":16,"RingCount":0,"Enabled":true,"Spanish":false,"HoldMusicFile":"Hold_Music.wav","Template_ID":41,"FrontLineForward":true,"DisclaimerFIle":"1Silence.wav"}]
Here is the parse code employing json-simple:
package parser;
import org.json.simple.*;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
import java.io.*;
public class JsonParser
{
private static JSONObject _jsonInput;
public static void main(String[] args)
{
//TODO
try{
JSONParser parser = new JSONParser();
Object obj = JSONValue.parse(args[0]);
JSONArray array=(JSONArray)obj;
String name = array.get(3).toString();
System.out.println(obj);
}
catch(Exception e){
e.printStackTrace();
}
}
}
The size of the array different than the index used
JSONParser parser = new JSONParser();
Object obj = parser.parse(new FileReader(args[1]));
JSONArray array=(JSONArray)obj;
if (array.size() > 3)
String name = array.get(3).toString();
I have this code and I tried to getting items from this JSON string but it failed.
I'm parsing the Json string from remote host.
package selectDB;
import java.io.*;
import java.net.URL;
import java.net.URLConnection;
import java.sql.*;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
import org.json.simple.*;
public class selectDB
{
public static void main(String[] args) throws IOException, ParseException
{
String s = "";
URL u = new URL("http://192.168.3.1/android/select.php");
URLConnection c = u.openConnection();
InputStream r = c.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(r));
for(String line; (line = reader.readLine()) != null;)
{
s+=line;
}
System.out.println(s);
}
}
the result is
{"result" : "true" , "messages" : [{"id":"866343023633578","latitute":"27","longitude":"31","number_phone":"01113171374"},{"id":"352168066354050","latitute":"27","longitude":"31","number_phone":"202222"},{"id":"50","latitute":"50","longitude":"100","number_phone":"50"},{"id":"110","latitute":"50","longitude":"50","number_phone":"110"},{"id":"120","latitute":"27","longitude":"31","number_phone":"120"},{"id":"130","latitute":"28","longitude":"29","number_phone":"120"},{"id":"140","latitute":"30","longitude":"40","number_phone":"140"},{"id":"800","latitute":"60","longitude":"30","number_phone":"800"},{"id":"353629054230064","latitute":"70","longitude":"80","number_phone":"120"}]}
Please help!
U can use the JsonReader class.
try (JsonReader in = Json.createReader(r)) {
JsonObject jsonObject= in.readObject();
YourObject obj = new YourObject();
obj.setSomething(jsonObject.getString("something", null));
// "something" is the key in the json file, null is the default
// when "something" was not found
} catch (JsonException | ClassCastException ex) {
throw new BadRequestException("Invalid Json Input");
}
you can use the Google Library GSON as well, it is easy to use and self explaining.
https://code.google.com/p/google-gson/
Gson Goals
Provide simple toJson() and fromJson() methods to convert Java objects to JSON and vice-versa
Allow pre-existing unmodifiable objects to be converted to and from JSON
Extensive support of Java Generics
Allow custom representations for objects
Support arbitrarily complex objects (with deep inheritance hierarchies and extensive use of generic types)