I have written java code for generating json of my searched data from file.But its not generating exact JsonArray. Its like
[{"item":"1617"},{"item":"1617"}]
instead of
[{"item":"747"},{"item":"1617"}].
Here 1617 is last item which is fetched from file.
JSONArray ja = new JSONArray();
JSONObject jo = new JSONObject();
while (products.readRecord())
{
String productID = products.get("user");
int j = Integer.parseInt(productID);
if(j == userId) {
itemid = products.get("item");
jo.put("item",itemid);
ja.add(jo);
}
}
out.println(ja);
products.close();
you are actually creating one jSONobject object to handle two objects, shouldn't you need to create JSONObjects in the while loop? something like this, so every iteration in while loop will create a new JSONObject and add it to JSONArray
JSONArray ja = new JSONArray();
while (products.readRecord())
{
String productID = products.get("user");
int j = Integer.parseInt(productID, 10);
if(j == userId)
{
JSONObject jo = new JSONObject();
itemid = products.get("item");
jo.put("item", itemid);
ja.add(jo);
}
}
out.println(ja);
products.close();
Extra:
i am not sure how java does conversion for string to integer, but i think you should always specify radix when using parseInt so the strings like '09' will not be treated as octal value and converted to wrong value (atleast this is true in javascript :))
Integer.parseInt(productID, 10);
You must re-instantiate your JSonObject inside the loop because when you modify it you modify the underlying object which is referenced several times by your array. Move your JSONObject jo = new JSONObject(); inside the loop and it should work fine.
Place JSONObject jo = new JSONObject(); inside the loop:
while (products.readRecord())
{
JSONObject jo = new JSONObject();
String productID = products.get("user");
int j = Integer.parseInt(productID);
// etc
}
Related
My JSON data look like this.
{"Users":[
{"Username":"Admin1", "Password":"123"},
{"Username":"Admin2", "Password":"456"},
{"Username":"Admin3", "Password":"789"}
]}
I am trying to extract out all the list of Username and Password.
JSONParser parser=new JSONParser();
Object obj = parser.parse(new FileReader("./Database/Users.json"));
JSONObject jsonObject = (JSONObject) obj;
JSONArray userArray = (JSONArray) jsonObject.get("Users");
How do I then iterate through this JSONArray to achieve what I wanted?
Sorry if I wasn't clear. I was using org.json.simple, not org.json. And the JSONArray does not have the int length() method.
What I did was
Iterator<JSONObject> iterator = userArray.iterator();
while (iterator.hasNext()) {
JSONObject factObj = (JSONObject) iterator.next();
String userName = (String) factObj.get("Username");
String passWord = (String) factObj.get("Password");
}
Read the javadoc ;)
If you are using org.json.JSONArray, you can loop using int length() to know the array's length and Object get(index) or JSONObject getJSONObject(index) to get an item of the array.
You can iterate with for loop
for (int i = 0; i < userArray.length(); ++i) {
JSONObject user = recs.getJSONObject(i);
...
}
you can probably do something like the following
for(int i = 0; i < userArray.length; i++) {
JSONObject user = userArray.getJSONObject(i);
String username = user.getString("Username");
String password = user.getString("Password");
//etc
}
I need to transform my data in a ArrayList to a JSON file, and I use JSON.simple. Everything is fine except one little thing that I want to get a result like ...... {source:0, target:1},{source:0, target:1},{source:0, target:2},{source:0, target:3} ...... but it returns ......{source:0, target:16},{source:0, target:16},{source:0, target:16}...... . My solution.size() is 17.
Here is my code:
JSONObject jsonObject = new JSONObject();
JSONObject jsonNodesObject = new JSONObject();
JSONObject jsonEdgesObject = new JSONObject();
JSONArray jsonNodesArray = new JSONArray();
JSONArray jsonEdgesArray = new JSONArray();
String instString = solutions.get(0).get("institution");
jsonNodesObject.put("name", instString);
// extract name and institution from ArrayList
for (int i = 0; i < solutions.size(); i++)
{
HashMap<String, String> eleHashMap= solutions.get(i);
String nameString = eleHashMap.get("name");
jsonNodesObject.put("name", nameString);
jsonNodesArray.add(jsonNodesObject);
jsonEdgesObject.put("source", 0);
jsonEdgesObject.put("target", i);
jsonEdgesArray.add(jsonEdgesObject);
}
jsonObject.put("nodes", jsonNodesArray);
jsonObject.put("edges", jsonEdgesArray);
System.out.println(jsonObject);
It seems that in every for loop, it refreshes the value of target: i of all my jsonEdgesArray.
Dose anyone know how to fix this? Thanks in advance!
As your iterating jsonNodesObject in for loop, same value will be put for jsonNodesObject.put("name", nameString); u have to initialize JSONObject jsonNodesObject = new JSONObject(); inside for loop
I have a JSON Object which converted into String and saved into database .But when i am trying to get it back it is throwing exception.My object is something like that...
{"COLUMN":["Type","Sub Type","F.P.","P.P.","Process","Due To Start"]}
How can we get the data back in Normal form?
My Java Code is.....
JSONObject obj = new JSONObject();
JSONArray the_json_array = obj.getJSONArray(userReorderOption);
int size = the_json_array.size();
ArrayList<JSONObject> arrays = new ArrayList<JSONObject>();
for (int i = 0; i < size; i++) {
JSONObject another_json_object = the_json_array.getJSONObject(i);
arrays.add(another_json_object);
}
And Exception i am getting....
net.sf.json.JSONException: JSONObject["{\"TASKLIST_COLUMN_REORDER\":[\"Type\",\"Sub Type\",\"F.P.\",\"P.P.\",\"Process\",\"Due To Start\"]}"] is not a JSONArray.
And this is java Code how i am creating JSON Object and saving into database...
String userReorderSelection;
Set set = new LinkedHashSet(userReorderSelection);
JSONObject json = new JSONObject();
json.accumulate("COLUMN", set);
saveJSONObj("PrimaryKeyColumn", json.toString());
Thanks Tichodroma,
But as i told i am using net.sf.json.JSONObject class and above things we can achieve from this class too..What i did to solve the above issue?...Please have a look on the Java code...
JSONObject jsonObj = new JSONObject();
JSONObject obj = jsonObj.fromObject(userReorderOption);
JSONArray columnName = (JSONArray) obj.get("COLUMN");
for (int i = 0; i < columnName.size(); i++) {
System.out.println(columnName.getString(i));
}
This code work fine for me with my Json Jar**(net.sf.json)**
Your JSON is not a JSONArray.
A JSONArray is an ordered sequence of values.
You have a JSONObject.
A JSONObject is an unordered collection of name/value pairs.
Edit:
Using the JSON implementation from org.codehaus.jettison.json, you can do this:
String json = "{\"COLUMN\":[\"Type\",\"Sub Type\",\"F.P.\",\"P.P.\",\"Process\",\"Due To Start\"]}";
JSONObject obj = new JSONObject(json);
JSONArray column = (JSONArray) obj.get("COLUMN");
for (int i = 0; i < column.length(); i++) {
final String field = column.getString(i);
System.out.println(field);
}
Result:
Type
Sub Type
F.P.
P.P.
Process
Due To Start
I have the following array returned to my JAVA Android application from PHP:
Array ( [0] => Array ( [referral_fullname] => Name 1 [referral_balance] => 500 ) [1] => Array ( [referral_fullname] => Name 2 [referral_balance] => 500 ) );
In Java they above array looks like this:
{"0":{"referral_fullname":"Name 1","referral_balance":"500"},"1":{"referral_fullname":"Name 2","referral_balance":"500"}};
For a simple JSONObject I'm using:
JSONTokener tokener = new JSONTokener(result.toString());
JSONObject finalResult = new JSONObject(tokener);
referral_fullname = finalResult.getString("referral_fullname");
but for an array of objects I don't know!
String str = your Json-> apply to.String();
JSONObject jObject = new JSONObject(str);
Map<String,String> map = new HashMap<String,String>();
Iterator iter = jObject.keys();
while(iter.hasNext()){
String key = (String)iter.next();
String value = jObject .getString(key);
map.put(key,value);
}
Your Json Syntax is wrong , JSONArray should be like this :
["0":{"referral_fullname":"Name 1","referral_balance":"500"},"1":{"referral_fullname":"Name 2","referral_balance":"500"}];
and to parse a JsonArray that contains some JSONObject , try this :
//parse the result
JSONObject jsonResult = null;
JSONArray arrayResult = null;
ArrayList<YourObject> listObjects = null;
try {
arrayResult = new JSONArray(result);
if(arrayResult != null) {
listObjects = new ArrayList<YourObject>();
int lenght = arrayResult.length();
for(int i=0; i< lenght; i++) {
JSONObject obj = arrayResult.getJSONObject(i);
YourObject object = new YourObject(obj);
listObjects.add(object);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
And add a constructor in your Class YourObject to convert your Json to an instance :
public YourObject(JSONObject json) {
if (!json.isNull("referral_fullname"))
this.referral_fullname = json.optString("referral_fullname", null);
if (!json.isNull("referral_balance"))
this.referral_balance = json.optString("referral_balance", null);
}
You should use
JSONArray finalResult = new JSONArray(tokener);
if you can. You structure is now an object with two fields, 0 and 1, which contains another object. You have to get an array of object in place of this composite object if you want to iterate easily like
JSONObject jso;
for(int i = finalResult.lenght-1; i >=0; i--){
jso = finalResult.get(i);
// jso == {"referral_fullname":"Name 1","referral_balance":"500"}
[whatever]
}
Try this.............
final JSONArray result_array = json.getJSONArray("result");
for (int i = 0; i < result.length(); i++) {
JSONObject joObject = result_array.getJSONObject(i);
String jName = joObject.get("referral_fullname").toString();
String jbalance = joObject.get("referral_balance").toString();
}
First make an JSON object and see then in inner level what you have if you have array then fetch array.
You need to make JSON object first. For example, if resp is a String (for example coming as http response)
JSONObject jsonObject = new JSONObject(resp);
jsonObject may contains other JSON Objects or JSON array. How to convert the JSON depends on the response.
If arraykey is a array inside the JSON objects then we can get list of array by the following way.
JSONArray arr = jsonObject.getJSONArray("arraykey");
Check the length of arr, if it is greater than 0 then it contains JSON objects or JSON array depending the data.
There is a complete example with some explanation about JSON String to JSON array can be found at
http://www.hemelix.com/JSONHandling
I am using the package org.json package: I need help with getting the corect data from the json in java. this is the string I have in json:
{"GetLocationsResult":[{"ID":82,"Name":"Malmo","isCity":true,"isCounty":false,"isDisctrict":false,"ID_Parent":null,"ID_Map":35,"ZipCode":"7000"},{"ID":82,"Name":"Trelleborg","isCity":true,"isCounty":false,"isDisctrict":false,"ID_Parent":null,"ID_Map":35,"ZipCode":"7000"}]}
This is a listing and this is just a test, it will contain more than 2 items, so my questions is, I want to get the name of all locations, I want to populate a spinner with names in my android app.
How can I get the "Name":"Malmo" and so on....
???
The answer is simple....The JSON element starts with a { which is a JSON Object, and GetLocationsResults is a JSON Array of JSON Objects. In essence, I translated the JSON String to the following code...
JSONObject rootJson = new JSONObject(jsonString);
JSONArray jsonArray = rootJson.getJSONArray("GetLocationsResult");
//Let's assume we need names....
String[] names = null;
if (jsonArray != null) {
names = new String[jsonArray.length()];
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject json = jsonArray.getJSONObject(i);
names[i] = json.getString("Name");
}
}
//Test
for (String name: names) {
System.out.println(name);
}