Converting Jsonarray to Arraylist
I Am Downloading a Json String and Converting It to Jsonarray. Im Putting It into a Listview and Need to Be Able to Delete from That Listview Later, and Since...
I am downloading a JSON string and converting it to JSONArray. Im putting it into a listview and need to be able to delete from that listview later, and since JSONArray has no .remove method (Thanks Obama), I am trying to convert it to an arraylist.
here is my JSON (the array.toString()):
[
{
"thumb_url":"tb1370913834.jpg",
"event_id":"15","count":"44",
"event_tagline":"this is a tagline",
"event_name":"5th birthday",
"event_end":"1370919600",
"event_start":"1370876400"
}
]
I need to get it into an array and be able to call the strings by their respective keys. Appreciate any help!
23 Answers
ArrayList<String> listdata = new ArrayList<String>();
JSONArray jArray = (JSONArray)jsonObject;
if (jArray != null) {
for (int i=0;i<jArray.length();i++){
listdata.add(jArray.getString(i));
}
}
I've done it using Gson (by Google).
Add the following line to your module's build.gradle:
dependencies {
// ...
// Note that `compile` will be deprecated. Use `implementation` instead.
// See for more info
implementation 'com.google.code.gson:gson:2.8.2'
}
JSON string:
private String jsonString = "[\n" +
" {\n" +
" \"id\": \"c200\",\n" +
" \"name\": \"Ravi Tamada\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c201\",\n" +
" \"name\": \"Johnny Depp\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c202\",\n" +
" \"name\": \"Leonardo Dicaprio\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c203\",\n" +
" \"name\": \"John Wayne\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c204\",\n" +
" \"name\": \"Angelina Jolie\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"female\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c205\",\n" +
" \"name\": \"Dido\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"female\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c206\",\n" +
" \"name\": \"Adele\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"female\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c207\",\n" +
" \"name\": \"Hugh Jackman\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c208\",\n" +
" \"name\": \"Will Smith\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c209\",\n" +
" \"name\": \"Clint Eastwood\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c2010\",\n" +
" \"name\": \"Barack Obama\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c2011\",\n" +
" \"name\": \"Kate Winslet\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"female\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"id\": \"c2012\",\n" +
" \"name\": \"Eminem\",\n" +
" \"email\": \"\",\n" +
" \"address\": \"xx-xx-xxxx,x - street, x - country\",\n" +
" \"gender\" : \"male\",\n" +
" \"phone\": {\n" +
" \"mobile\": \"+91 0000000000\",\n" +
" \"home\": \"00 000000\",\n" +
" \"office\": \"00 000000\"\n" +
" }\n" +
" }\n" +
" ]";
ContactModel.java:
public class ContactModel {
public String id;
public String name;
public String email;
}
Code for converting a JSON string to ArrayList<Model>:
Note: You have to import java.lang.reflect.Type;:
// Top of file
import java.lang.reflect.Type;
// ...
private void parseJSON() {
Gson gson = new Gson();
Type type = new TypeToken<List<ContactModel>>(){}.getType();
List<ContactModel> contactList = gson.fromJson(jsonString, type);
for (ContactModel contact : contactList){
Log.i("Contact Details", contact.id + "-" + contact.name + "-" + contact.email);
}
}
Hope this will help you.
I have fast solution. Just create a file ArrayUtil.java
import java.util.ArrayList;
import java.util.Collection;
import org.json.JSONArray;
import org.json.JSONException;
public class ArrayUtil
{
public static ArrayList<Object> convert(JSONArray jArr)
{
ArrayList<Object> list = new ArrayList<Object>();
try {
for (int i=0, l=jArr.length(); i<l; i++){
list.add(jArr.get(i));
}
} catch (JSONException e) {}
return list;
}
public static JSONArray convert(Collection<Object> list)
{
return new JSONArray(list);
}
}
Usage:
ArrayList<Object> list = ArrayUtil.convert(jArray);
or
JSONArray jArr = ArrayUtil.convert(list);
try this way Simply loop through that, building your own array. This code assumes it's an array of strings, it shouldn't be hard to modify to suit your particular array structure.
JSONArray jsonArray = new JSONArray(jsonArrayString);
List<String> list = new ArrayList<String>();
for (int i=0; i<jsonArray.length(); i++) {
list.add( jsonArray.getString(i) );
Instead of converting the JSON string to an ArrayList or even a Map, you can just create a JSONObject itself. This object has the ability to get string values by key, as you want and also to remove objects.
To create a JSONObject from a properly formatted JSON string, you simply call the appropriate constructor.
JSONObject json = new JSONObject(jsonString);
In Java 8,
IntStream.range(0,jsonArray.length()).mapToObj(i->jsonArray.getString(i)).collect(Collectors.toList())
JSONArray array = new JSONArray(json);
List<JSONObject> list = new ArrayList();
for (int i = 0; i < array.length();list.add(array.getJSONObject(i++)));
To make it handy, use POJO.
try like this..
List<YourPojoObject> yourPojos = new ArrayList<YourPojoObject>();
JSONObject jsonObject = new JSONObject(jsonString);
YourPojoObject yourPojo = new YourPojoObject();
yourPojo.setId(jsonObject.getString("idName"));
...
...
yourPojos.add(yourPojo);
I have fast solution. Just create a file ArrayUtil.java
ObjectMapper mapper = new ObjectMapper();
List<Student> list = Arrays.asList(mapper.readValue(jsonString, Student[].class));
Usage:
ArrayList<Object> list = ArrayUtil.convert(jArray);
or
JSONArray jArr = ArrayUtil.convert(list);
if you want to extract data form JSON string array, here is my working code. change parameter as your data.
PoJo class
public class AllAppModel {
private String appName;
private String packageName;
private int uid;
private boolean isSelected;
private boolean isSystemApp;
private boolean isFav;
}
Marcus Vance is a cybersecurity auditor and technology writer dedicated to educating the public about online safety, data privacy regulations, enterprise security, and emerging cyber threats.
