In java, I am trying to parse values from this json..
[
{
"2012-01-02": {
"age": 3,
"dob": "2010-01-03",
"name": "jack"
},
"2012-01-03": {
"age": 3,
"dob": "2010-01-04",
"name": "jill"
},
"2012-01-04": {
"age": 3,
"dob": "2010-01-05",
"name": "john"
},
"2012-01-05": {
"age": 3,
"dob": "2010-01-06",
"name": "miran"
}
}
]
Using JSONObject, I was trying to get the value of just "age" and then add them up to do some data manipulation.
I created a JSONObject
Created an iterator and then stored them to a map
This gets me the inner element like:
{
"age": 3,
"dob": "2010-01-06",
"name": "miran"
}
After this, not sure how to extract just age from each element. Do i create another jsonobject and pass this new string, extract age out of it or is there a better way to do this? (I am sure there is one)
UPDATE:
This is what I currently have that gives me {"age":3,"dob":"2012-01-06","name":"miran"}
JSONObject jsonobj = new JSONObject();
try {
jsonobj = new JSONObject(pastweekVol);
Iterator iter = jsonobj.keys();
Map<String, String> map = new HashMap<String, String>();
while(iter.hasNext()){
String jsonkey = (String)iter.next();
String value = jsonobj.getString(jsonkey);
logger.debug("first pass value is: {}", value);
} catch (JSONException je) {
logger.debug("exception is: {}",je);
}
I was thinking that since I am getting {"age":3,"dob":"2012-01-06","name":"miran"}, I would create another json object and pass in this string, which will give me value of "age". The problem here is that I get repetitive values. Of course, something very basic is missing here but I can't seem to figure that out.
If you have the inner element as a JSONObject instance - say person - then you can directly access the age:
int age = person.getInt("age");
and do something with it:
sum += age;
You might consider a library like Google's GSON (http://code.google.com/p/google-gson/) if you want to be able to easily parse arbitrarily complex JSON strnigs into generic objects.
Using org.json is probably not your best bet -- this API has many flaws. Using Jackson, you can easily extract age from each member value:
ObjectMapper mapper = new ObjectMapper();
JsonNode fullDocument = mapper.readTree(xxx); // xxx can be many things
// Not an object? Bail out
if (!fullDocument.isObject())
throw new IllegalArgumentException("not an object");
// This will iterate through object values
for (JsonNode value: fullDocument)
// do something with value.get("age")
// in particular, you can test for .isIntegralNumber()
Related
I have a string like below
{
"id": "abc",
"title": "123.png",
"description": "fruits",
"information": [
{
"type": "apple",
"url": "https://apple.com"
},
{
"type": "orange",
"url": "https://orange.com"
}
],
"versions": 0
}
I want to get the value of url where type: orange. The list in information may not always be in same order as appearing in the data above. I know I could do it easily in python with json.loads and json.dump.
I am trying to do it java using JsonNode and objectMapper.readTree.at("/information") but I am unable to get past this point in a clever neat way to get the list and fetch the url where type = orange.
This is pretty straightforward
Use a JSON library and parse the response using the library. Then get only the values and attributes that you need...
Example relevant to your case:
// Get your Json and transform it into a JSONObject
JSONObject mainObject = new JSONObject(yourJsonString); // Here is your JSON...
// Get your "information" array
JSONArray infoArray = mainObject.getJSONArray("information"); // Here you have the array
// Now you can go through each item of the array till you find the one you need
for(int i = 0 ; i < infoArray.length(); i++)
{
JSONObject item = participantsArray.getJSONObject(i);
final String type = item.getString("type");
final String url = item.getString("url");
if(type.equals("orange"))
{
// DO WHATEVER YOU NEED
}
}
I am building a tool using java, that accesses an API.
I'm trying to let the user decide, which parameters to use (via checkboxes for instance).
So the user would decide to take one of let's say 5 parameters:
p1
p2
p3
p4
p5
and then I would make a call to the API using those parameters and receive a Json String as a response.
So that Json String can be either
{"data":[{"p1":"value1", "p2":"value2", "p3":"value3", "p4":"value4", "p5":"value5"}]}
{"data":[{"p1":"value1", "p2":"value2", "p3":"value3", "p4":"value4"}]}
{"data":[{"p1":"value1", "p2":"value2", "p3":"value3"}]}
{"data":[{"p1":"value1", "p2":"value2"}]}
or
{"data":[{"p1":"value1"}]}
I'm trying to print everything inside "data" to the console. This is the code I got so far:
JsonParser parser = new JsonParser();
JsonObject json = (JsonObject)
parser.parse(adsInsights.toString());
System.out.println(json.get("p1").getAsString() + "\t"
+ json.get("p2").getAsString() + "\t"
+ json.get("p3").getAsString() + "\t"
+ json.get("p4").getAsString() + "\t" +
json.get("p5").getAsString()
);
My problem is: how do I determine which ones to print, without doing a ton of if/elses?
All I need is every variable within "data". is there a method to do this?
EDIT:
First of all, thanks for all the answers.
For future reference I guess, this is what I did:
//getting the keys, which the user has selected. Detailed implementation irrelevant for this matter
String selectedKeys[] = getSelectedKeys();
JsonParser parser = new JsonParser();
JsonObject json = (JsonObject)
parser.parse(adsInsights.toString());
for(int i = 0; i < selectedKeys.length; i++) {
if(json.has(selectedKeys[i])) {
System.out.print(json.get(selectedKeys[i]).getAsString() + "\t");
}
}
System.out.println();
You can iterate over the Json keys no matter which keys are in it and print their values.
JsonParser parser = new JsonParser();
JsonObject json = (JsonObject)
parser.parse(adsInsights.toString());
for (key: json.keys) {
System.out.print(json.get(key).getAsString());
}
// to check if key exists or not. if not, return empty string.
private String getValues(JSONObject jsonObj, String arg) {
return jsonObj.get(arg) != null?(String) jsonObj.get(arg):"";
}
//call getValues function for every key. fetch all keys from keySet Function.
JSONObject check=(JSONObject) obj;
JSONObject data=(JSONObject) check.get("data");
Set<String> keys=data.keySet();
for(String k:keys){
System.out.println(getValues(data,k));
}
Are you building the API as well?
I think a better data structure to return from the API would be to use an array for "data", e.g.
{
"data":[
{ "id": "p1", "value": "value1" },
{ "id": "p2", "value": "value2" },
{ "id": "p3", "value": "value3" },
{ "id": "p4", "value": "value4" },
{ "id": "p5", "value": "value5" }
]
}
That way, the receiving code doesn't have to care about which items are in data, or how many. Instead it can just loop through the array and print whatever happens to be there.
I have json file in below format.
{
"data":[
{
"prjId": 1,
"name" : "Forj1",
"issue": [
{
"id": 00001,
"status" : "Closed"
},
{
"id": 00002,
"status" : "Open"
}
]
},
{
"prjId": 2,
"name" : "Forj2",
"issue": [
{
"id": 00003,
"status" : "Closed"
},
{
"id": 00004,
"status" : "Open"
}
]
}],
"issueCounter": 7,
"success": true
}
Here "data" is array of projects, and within project attribute there is array of "issue".
So far if I remove "issue" array, I am able to traverse the json to one level down in "data" attribute, If this json has "issue" array I get an error saying missing comma.
javax.json.stream.JsonParsingException: Invalid token=NUMBER at (line no=15, column no=14, offset=242) Expected tokens are: [COMMA]
Below is the code that I have right now. I have two problems with this, one is the error while reading if I place the "issue" attribute, and secondly a way to read the "issue" array and traverse all attributes within.
InputStream fis = new FileInputStream(pathToFile+"data3.json");
JsonReader jsonReader = Json.createReader(fis);
//the error is thrown on below line while reading the above json.
JsonObject jsonObject = jsonReader.readObject();
jsonReader.close();
fis.close();
System.out.println(jsonObject.getInt("issueCounter"));
//reading arrays from json
JsonArray jsonArrayData = jsonObject.getJsonArray("data");
Project [] prj = new Project[jsonArrayData.size()];
int index = 0;
for(JsonValue value : jsonArrayData){
JSONObject jsonObj = new JSONObject(value.toString());
System.out.println(jsonObj.getString("name"));
System.out.println(jsonObj.getInt("prjId"));
//this is also the place where I am stuck, I know I need to construct an array out of it by obtaining issue attribute. Below is very very wrong.
/*
JsonArray jsonArrayIssue = jsonObj.getJsonArray("issue");
for(JsonValue issue : jsonArrayIssue){
JSONObject jsonIssueObj = new JSONObject(issue.toString());
System.out.println(jsonIssueObj.getString("status"));
System.out.println(jsonIssueObj.getInt("id"));
}
*/
}
Any help or pointers is deeply appreciated. I can tweak the json if its required ultimately I need to maintain an array of issues.
The problem as others said is the JSON.
"id": 00001 <-- this is a number, numbers cannot start with a leading zero as per JSON stadard.
If you control the JSON you should tweak it.
Alternatively ff you don't, you can use a less strict parser like org.json.simple https://mvnrepository.com/artifact/com.googlecode.json-simple/json-simple
The code will be the same as yours, just adjusted to org.json.simple
try { ...
JSONObject rootJSON = (JSONObject) new JSONParser().parse(jsonString);
JSONArray dataList = (JSONArray) rootJSON.get("data");
for(Object projectObj: dataList.toArray()){
JSONObject project = (JSONObject)projectObj;
JSONArray issueList = (JSONArray) project.get("issue");
for(Object issueObj: issueList.toArray()){
JSONObject issue = (JSONObject) issueObj;
//do something with the issue
}
}
} catch (ParseException e) {
//do smth
e.printStackTrace();
}
Your json data is invalid.You can check here.
http://jsonlint.com
...issue": [{ "id": 00001,
"status": ----------------------^
Your id must be string number,string,boolean.Send 1,2,3,.... as return values and check if it works.
Your code looks okay the problem is the JSON formatting. Specifically the following lines:
"id": 00001,
"id": 00002,
"id": 00003,
"id": 00004,
Basically if you want it in that format you will need to set them as strings by wrapping the values in quotations i.e. "id": "00001" or you can use a valid number i.e. "id": 1
I am new To JSon and i want to search the following json string and get the required output.
String:
{"status":"Success","code":"200","message":"Retrieved Successfully","reason":null,"
"projects":
[
{
"projectName": "example",
"users":
[
{
"userName": "xyz",
"executions":
[
{
"status": "check",
"runs":
[
{
"Id": "------",
"Key": "---"
}
],
"RCount": 1
}
],
"RCount": 1
}
],
"RCount": 1
},
Like that i have many projects and now , if i give projectname and username as input i wantt to get its status as output.
Is it possible?If yes how?
You may use JSONObject for this.
JSONObject json = new JSONObject(string);
JSONArray[] projectsArray = json.getJSONArray("projects");
for(int i = 0; i < projectsArray.length; ++i)
{
String projectName = projectsArray[i].getString("projectName");
...
}
Use the same method to get the users.
You can use gson library. Using gson convert your json string to Map and then you can iterate through map to get required item
Type type = new TypeToken<Map<String, Object>>(){}.getType();
Map<String, Object> myMap = gson.fromJson(jsonString, type);
You can use the Google gson to map your json data structure to a Java POJOs.
Example :
You can have Projects class containing list/array of Users.
Users class containing list/array of Executions and so on.
Gson library can easily map the json to these classes as objects and you can access your data in a more elegant manner.
Here are a few references :
http://howtodoinjava.com/2014/06/17/google-gson-tutorial-convert-java-object-to-from-json/
http://www.mkyong.com/java/how-do-convert-java-object-to-from-json-format-gson-api/
I know its an array, but I am completely new to JSON and need help comprehending how this is structured, here is my attempt at extracting data:
String JSonString = readURL("//my URL is here");
JSONArray s = JSONArray.fromObject(JSonString);
JSONObject Data =(JSONObject)(s.getJSONObject(0));
System.out.println(Data.get("name"));
My JSON data that I have goes like this :
{
"sports": [
{
"name": "basketball",
"id": 40,
"uid": "s:40",
"leagues": [
{
"name": "National Basketball Assoc.",
"abbreviation": "nba",
"id": 46,
"uid": "s:40~l:46",
"groupId": 7,
"shortName": "NBA",
"athletes": []
}
]
}
],
"resultsOffset": 10,
"resultsLimit": 10,
"resultsCount": 1,
"timestamp": "2013-11-18T03:15:43Z",
"status": "success"
}
I dont really have a strong grasp of this stuff so all the help is appreciated.
Here is the idea :
JSONObject root = new JSONObject(yourJsonString);
JSONArray sportsArray = root.getJSONArray("sports");
// now get the first element:
JSONObject firstSport = sportsArray.getJSONObject(0);
// and details of the first element
String name = firstSport.getString("name"); // basketball
int id = firstSport.getInt("id"); // 40
JSONArray leaguesArray = firstSport.getJSONArray("leagues");
// and so on, you can process leaguesArray similarly
It should work (feel free to complain about compile errors if there are any)
Your JSON data is an object (it starts with a curly brace). In the next inner layer, there is a single array (at key "sports"):
String jsonString = readURL("//my URL is here");
JSONObject result = JSONObject(jsonString);
JSONArray sports = result.getJSONArray("sports");
JSONObject sport = sport.getJSONObject(0);
System.out.println(sport.getString("name"));
I might have used another JSON library than you.
JSON means JavaScript Object Notation.
Objects in javascripts are just containers and can be represented by key-value pairs. Please find below notations to understand about json.
Represent objects in json: E.g. Student
{"name" : "Robin", "rollnumber" : "1"}
Represent array in json : E.g. Array of students
[{"name" : "Robin", "rollnumber" : "1"}, {"name" : "Mark", "rollnumber" : "2"}]
You can understand more on JSON from diagrams on this link http://www.json.org/fatfree.html
There are various ways available to to convert JSON to javaobject and javaobject to JSON : One of them is http://wiki.fasterxml.com/JacksonInFiveMinutes
Adding detailed code here along with the imports .
If this helps.
import org.json.JSONException;
import org.json.JSONObject;
public class extractingJSON {
public static void main(String[] args) throws JSONException {
// TODO Auto-generated method stub
String jsonStr = "{\"name\":\"SK\",\"arr\":{\"a\":\"1\",\"b\":\"2\"},\"arrArray\":[{\"a\":\"1\",\"b\":\"2\"}]}";
JSONObject jsonObj = new JSONObject(jsonStr);
String name = jsonObj.getString("name");
System.out.println(name);
String first = jsonObj.getJSONObject("arr").getString("a");
System.out.println(first);
first = jsonObj.getJSONArray("arrArray").getJSONObject(0).getString("a");
System.out.println(first);
}
}