If I read the JSONArray constructors correctly, you can build them from any Collection (arrayList is a subclass of Collection) like so:
ArrayList<String> list = new ArrayList<String>();
list.add("foo");
list.add("baar");
JSONArray jsArray = new JSONArray(list);
References:
- jsonarray constructor: http://developer.android.com/reference/org/json/JSONArray.html#JSONArray%28java.util.Collection%29
- collection: http://developer.android.com/reference/java/util/Collection.html
If I read the JSONArray constructors correctly, you can build them from any Collection (arrayList is a subclass of Collection) like so:
ArrayList<String> list = new ArrayList<String>();
list.add("foo");
list.add("baar");
JSONArray jsArray = new JSONArray(list);
References:
- jsonarray constructor: http://developer.android.com/reference/org/json/JSONArray.html#JSONArray%28java.util.Collection%29
- collection: http://developer.android.com/reference/java/util/Collection.html
Use Gson library to convert ArrayList to JsonArray.
Gson gson = new GsonBuilder().create();
JsonArray myCustomArray = gson.toJsonTree(myCustomList).getAsJsonArray();
Videos
If you want or need to work with a Java array then you can always use the java.util.Arrays utility classes' static asList() method to convert your array to a List.
Something along those lines should work.
String mStringArray[] = { "String1", "String2" };
JSONArray mJSONArray = new JSONArray(Arrays.asList(mStringArray));
Beware that code is written offhand so consider it pseudo-code.
ArrayList<String> list = new ArrayList<String>();
list.add("blah");
list.add("bleh");
JSONArray jsArray = new JSONArray(list);
This is only an example using a string arraylist
put adds the list as an element to the JSONArray. Thats not what you want. You want your JSONArray to represent the list.
JSONArray offers a constructor for that:
val jsonArray = JSONArray(listOf(1, 2, 3))
But there is a much easier way. You don't need to worry about single properties. Just pass the whole POJO.
Let's say you have this:
class QuoteData(val id: Int, val quoteId: Int, travellerId: Int?)
class TravelerData(val userQuoteTravellers: List<QuoteData>)
val travelerData = TravelerData(listOf(QuoteData(1354, 546, null)))
You just have to pass travelerData to the JSONArray constructor:
val travelerDataJson = JSONArray(travelerData)
and it will be represented like this:
"userQuoteTravellers": [ { "id": 1354, "quoteId": 526, "travellerId": null } ]
With Dependencies
Add to your gradle:
implementation 'com.squareup.retrofit2:converter-gson:2.3.0'
Convert ArrayList to JsonArray
val jsonElements = (JsonArray) new Gson().toJsonTree(itemsArrayList)
Without Dependencies
val jsonElements = JSONArray(itemsArrayList)
If you want to work with json go this library, this library has a nice support https://code.google.com/p/google-gson/.
This is an example:
Gson gson = new Gson();
Collection<Integer> ints = Lists.immutableList(1,2,3,4,5);
(Serialization)
String json = gson.toJson(ints); ==> json is [1,2,3,4,5]
Thanks
org.json and org.json.simple JSON parser use raw types of collections underneath. If you're looking for good Generics support try Google Gson. Here's how you would go about serializing your generic ArrayList with Gson:
Gson gson = new Gson();
ArrayList<String> arrayList= (ArrayList<String>) ClassName.getArrayList();
// Serializing to a JSON element node
JsonElement jsonElement = gson.toJsonTree(arrayList);
System.out.println(jsonElement.isJsonArray()); // true
// Or, directly to JSON string
String json = gson.toJson(arrayList);
System.out.println(json);
Here's how you would deserialize the same JSON string with its Generics intact:
Type type = new TypeToken<ArrayList<String>>(){}.getType();
ArrayList<String> arrayList = gson.fromJson(json, type);
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 https://stackoverflow.com/a/44409111 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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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\": \"[email protected]\",\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.
This is overly complicated, Jackson handles lists via its writer methods just as well as it handles regular objects. This should work just fine for you, assuming I have not misunderstood your question:
public void writeListToJsonArray() throws IOException {
final List<Event> list = new ArrayList<Event>(2);
list.add(new Event("a1","a2"));
list.add(new Event("b1","b2"));
final ByteArrayOutputStream out = new ByteArrayOutputStream();
final ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(out, list);
final byte[] data = out.toByteArray();
System.out.println(new String(data));
}
I can't find toByteArray() as @atrioom said, so I use StringWriter, please try:
public void writeListToJsonArray() throws IOException {
//your list
final List<Event> list = new ArrayList<Event>(2);
list.add(new Event("a1","a2"));
list.add(new Event("b1","b2"));
final StringWriter sw =new StringWriter();
final ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(sw, list);
System.out.println(sw.toString());//use toString() to convert to JSON
sw.close();
}
Or just use ObjectMapper#writeValueAsString:
final ObjectMapper mapper = new ObjectMapper();
System.out.println(mapper.writeValueAsString(list));
Your description doesn't match your post title. What is your actual question?
Both Powershell and JSON don't particularly care about the structure of your data. In PS you can have an array of various objects (it sees everything as object anyway) and JSON allows for optional fields so the missing fields in the first value won't impact the structure.
# Using a hash object here for convenience
$item1 = @{ basePrice = 100; category = "some category"; packageWeightUnit = "g"; productType = "Some type" }
$item2 = @{ basePrice = 100; category = "some category"; packageWeightUnit = "g"; productType = "Some type"; attributes = @{ colour = @("blue", "red"); hight = @(100) } }
# Assuming you have more items than this...
$list = New-Object System.Collections.ArrayList
$list += $item1
$list += $item2
ConvertTo-Json $list -depth 4
To go the other way, given the previous JSON
$readItems = ConvertFrom-Json $json
$list.add(@{"name"=$red.name;
"description"=$desc;
"coverImage"=$red.coverImage;
"ean"=$red.ean;
"packageWeightValue"=$red.packageWeightValue;
"packageWeightUnit"=$red.packageWeightUnit;
"basePrice"=$red.basePrice;
"vat"=$red.vat;
"stockLevel"=$red.stockLevel;
"sku"=$red.sku;
"gallery"=$galerija;
"brand"=$red.brand;
"productType"=$red.productType;
"category"=$red.category;
attributes = @{ "key features" = @($features.naziv)}
})
and i am getting no error but output looks like
"attributes": {
"key features": "PARIS Hidratacija Balzam"
},
but it should be
"attributes": {
"key features": ["PARIS", "Hidratacija", "Balzam""
},
You can convert your JsonArray or json string to ArrayList<OBJECT> using Gson library as below
ArrayList<OBJECT> yourArray = new Gson().fromJson(jsonString, new TypeToken<List<OBJECT>>(){}.getType());
//or
ArrayList<OBJECT> yourArray = new Gson().fromJson(myjsonarray.toString(), new TypeToken<List<OBJECT>>(){}.getType());
Also while converting your ArrayList<OBJECT> to JsonArray, no need to convert it to string and back to JsonArray
JsonArray myjsonarray = new Gson().toJsonTree(MyArrayList<OBJECT>).getAsJsonArray();
Refer Gson API documentation for more details. Hope this will be helpful.
JSONArray is just a subclass of object, so if you want to get the JSONObjects out of a JSONArray into some other form, JSONArray doesn't have any convenient way to do it, so you have to get each JSONObject and populate your ArrayList yourself.
Here is a simple way to do it:
ArrayList<JSONObject> arrayList = new ArrayList(myJSONArray.length());
for(int i=0;i < myJSONArray.length();i++){
arrayList.add(myJSONArray.getJSONObject(i));
}
EDIT:
OK, you edited your code to show that you are using GSON. That is a horse of a different color. If you use com.google.gson.JsonArray instead of JSONArray, you can use the Gson.fromJson() method to get an ArrayList.
Here is a link: Gson - convert from Json to a typed ArrayList