I have the following SP (SQL server) that return a Json output.
BEGIN
SET #jsonOutput = (
SELECT
Program.Name AS ProgramName,
ProgramOwner.FirstName AS OwnerFirstName,
FROM ProgramOwner, Program
WHERE Program.Id = ProgramOwner.ProgramOwner2Program
FOR JSON PATH,WITHOUT_ARRAY_WRAPPER)
I would like to map the return Json output to a List of ProgramDto via modelMapper. Not sure hot to do that since the return values from call.execute is an Object.
Something like this:
SimpleJdbcCall call = new
SimpleJdbcCall(jdbcTemplate).withProcedureName(programProc).declareParameters(
new SqlOutParameter("jsonOutput", Types.VARCHAR));
Map<String,Object>out = call.execute(new MapSqlParameterSource());
if(out.size()>0) {
// Only to show what I am trying to do
Type rootType = new TypeToken<List<ProgramDto>>() {}.getType();
modelMapper.map(out.get("jsonOutput"),rootType );
}
Thank you
As I understood you are trying to get a list of object from
You can use Jackson api
Like this
say for example your json is in variable named jsonData, then you can get the object you need like below.
ObjectMapper mapper = new ObjectMapper();
List<Type> myList = Arrays.asList(mapper.readValue(jsonData, Type[].class));
You can also find more examples here
Related
My servlet recieves/loads multiple parameters from/for an article (price, id, count, name).
While they are saved in the session for other purposes I want to display them in a Shopping cart.
So my idea was to get all values into a json like this
{"id":1, "prductName":"article1"}
but my json always ends up empty.
I had two approaches:
String prname = request.getParameter("name");
String anz = String.valueOf(session.getAttribute("Anzahl"));
String prid = request.getParameter("id");
String price = request.getParameter("price");
These are my parameters:
First try:
class ToJson{
String prname1 = String.valueOf(session.getAttribute("prname"));
String anz1 = String.valueOf(session.getAttribute("Anzahl"));
String prid1 = String.valueOf(session.getAttribute("id"));
String price1 = String.valueOf(session.getAttribute("price"));
}
ToJson obj = new ToJson();
Jsonb jsonb = JsonbBuilder.create();
String jsn1 = jsonb.toJson(obj);
Ends up with: {}
Second try:
ArrayList<String> ar = new ArrayList<String>();
ar.add(prname);
ar.add(price);
ar.add(prid);
ar.add(anz);
ToJson obj = new ToJson();
Jsonb jsonb = JsonbBuilder.create();
String jsn = jsonb.toJson(ar);
Ends up with: ["P1neu","25","1","145"]
It isn't in a format I wanted and I also don't know how to access the seperate values here, I tried jsn[1] but it didnt work.
Could you help me, please?
To your first question, why JSON object is printing empty:
You are missing getters & setters in the ToJSON class for JSON Builder/Parser to access the properties/fields, and that's why its printing as empty object.
To your second question, how do I access JSON properties:
JSON representation is a natively a string representation, and you can't read part of string as jsn[1].
For reading JSON object properties, you convert it into POJO using available any of preferred open source parser libraries like Jacksons, Gson etc. And then access POJO properties using standard java getter/setters.
In my Android app, I used Gson in order to save/load the object's Arraylist in SharedPreferences. Follows are my code using Gson.
public static ArrayList<RequestModal> getModalList(Context ctx) {
Gson gson = new Gson();
String json = getSharedPreferences(ctx).getString("ModalList", new Gson().toJson(new ArrayList<>()));
Type type = new TypeToken<ArrayList<RequestModal>>() {}.getType();
return gson.fromJson(json, type);
}
In here "RequestModal" is the simple object include a bit of strings and integers.
It works well in case "online". But if internet is offline, forever works on below code.
Type type = new TypeToken<ArrayList<RequestModal>>() {}.getType();
How can I solve it? What is the way implement the feature like this with/without using Gson? Please help me anyone having a good idea.
Thank you in advance.
You can implement this without Gson:
public static EpisodeDetails parseEpisodeDetails(String content) {
EpisodeDetails episodeDetails = new EpisodeDetails();
try {
JSONObject jsonObject = new JSONObject(content);
episodeDetails.title = jsonObject.getString("title");
episodeDetails.subTitle = jsonObject.getString("subtitle");
episodeDetails.synopsis = jsonObject.getString("synopsis");
episodeDetails.ends_on = jsonObject.getString("ends_on");
JSONArray images = jsonObject.getJSONArray("image_urls");
if (images.length() > 0) {
episodeDetails.image_url = images.getString(0);
}
} catch (JSONException e) {
e.printStackTrace();
return null;
}
return episodeDetails;
}
What I'm doing is just taking the String, in your case the one saved on the shared prefs called ModalList and inserting the values on my structure, on my code the structure is called EpisodeDetails, on your code the correspondent is RequestModal. If you don't want to do it via code and want to try another library I recommend Jackson.
Another thing, on this line:
String json = getSharedPreferences(ctx).getString("ModalList", new Gson().toJson(new ArrayList<>()));
Your second parameter is not necessary. getString takes the key to load as first parameter and a default value as second paramter (in the case of empty result). You could change this to "" or null.
Well, another solution to your problem could be TinyDB. It makes use of Gson to save ArrayLists of objects in sharedPrefs, its usage is so simple as:
Person person = new Person("john", 24);
tinydb.putObject("user1", person);
ArrayList<Person> usersWhoWon = new ArrayList<Person>();
tinydb.putListObject("allWinners", usersWhoWon);
and that's it, check out my link given above to see the usage details.
I'm building an Nativesctipt app for Android that uses Firebase as backend and I'm using the native Firebase Android library v2.4.0
I can insert objects in Firebase just fine using the following {N} Javascript syntax
var user = new java.util.HashMap();
user.put("name", viewModel.get("name"));
user.put("lastName", viewModel.get("lastName");
var address = new java.util.HashMap();
address.put("address", viewModel.get("address");
address.put("number", viewModel.get("number");
address.put("city", viewModel.get("city");
user.put("address", address);
ref = new Firebase("https://my-firebase-app-url/users");
refUser = ref.child(viewModel.get("username"));
refUser.setValue(user);
The problem with this is that I have to manually convert every javascript object into a java hashSet (and back) and I wanted to do it using a JSON to HashMap library so I have imported the java Jackson library into my {N} app.
According to this site here's the way to convert a JSON to a HashMap in Java using Jackson:
ObjectMapper mapper = new ObjectMapper();
String json = "{\"name\":\"mkyong\", \"age\":29}";
Map<String, Object> map = new HashMap<String, Object>();
// convert JSON string to Map
map = mapper.readValue(json, new TypeReference<Map<String, String>>(){});
I'm looking for a way to translate that into a {N} Javascript code that will do it for me but I'm unable to use generics notation in {N} Javascript. Does anybody know how I could do it? I have tried some ways but all of them crashed the application. Here's an {N} Javascript snippet does not work:
var ObjectMapper = com.fasterxml.jackson.databind.ObjectMapper;
var TypeReference = com.fasterxml.jackson.core.type.TypeReference;
var mapper = new ObjectMapper();
var map = mapper.readValue(JSON.stringify(user), new TypeReference());
refUser.setValue(map);
Any help is greatly appreciated.
HttpGet getRequest=new HttpGet("/rest/auth/1/session/");
getRequest.setHeaders(headers);
httpResponse = httpclient.execute(target,getRequest);
entity = httpResponse.getEntity();
System.out.println(EntityUtils.toString(entity));
Output as follows in json format
----------------------------------------
{"session":{"name":"JSESSIONID","value":"5F736EF0A08ACFD7020E482B89910589"},"loginInfo":{"loginCount":50,"previousLoginTime":"2014-11-29T14:54:10.424+0530"}}
----------------------------------------
What I want to know is how to you can manipulate this data using Java without writing it to a file?
I want to print name, value in my code
Jackson library is preferred but any would do.
thanks in advance
You may use this JSON library to parse your json string into JSONObject and read value from that object as show below :
JSONObject json = new JSONObject(EntityUtils.toString(entity));
JSONObject sessionObj = json.getJSONObject("session");
System.out.println(sessionObj.getString("name"));
You need to read upto that object from where you want to read value. Here you want the value of name parameter which is inside that session object, so you first get the value of session as JSONObject using getJSONObject(KeyString) and read name value from that object using function getString(KeyString) as show above.
May this will help you.
Here's two ways to do it without a library.
NEW (better) Answer:
findInLine might work even better. (scannerName.findInLine(pattern);)
Maybe something like:
s.findInLine("{"session":{"name":"(\\w+)","value":"(\\w+)"},"loginInfo":{"loginCount":(\\d+),"previousLoginTime":"(\\w+)"}}");
w matches word characters (letters, digits, and underscore), d matches digits, and the + makes it match more than once (so it doesnt stop after just one character).
Read about patterns here https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html
OLD Answer:
I'm pretty sure you could use a scanner with a custom delimiter here.
Scanner s = new Scanner(input).useDelimiter("\"");
Should return something like:
{
session
:{
name
:
JSESSIONID
,
value
:
5F736EF0A08ACFD7020E482B89910589
And so on. Then just sort through that list/use a smarter delimiter/remove the unnecessary bits.
Getting rid of every other item is a pretty decent start.
https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html has info on this.
I higly recomend http-request built on apache http api.
private static final HttpRequest<Map<String, Map<String, String>>> HTTP_REQUEST = HttpRequestBuilder.createGet(yourUri, new TypeReference<Map<String, Map<String, String>>>{})
.addDefaultHeaders(headers)
.build();
public void send(){
ResponseHandler<Map<String, Map<String, String>>> responseHandler = HTTP_REQUEST.execute();
Map<String, Map<String, String>> data = responseHandler.get();
}
If you want use jackson you can:
entity = httpResponse.getEntity();
ObjectMapper mapper = new ObjectMapper();
Map<String, Map<String, String>> data = mapper.readValue(entity.getContent(), new TypeReference<Map<String, Map<String, String>>>{});
I have some model classes like Customer, Product, etc. in my project which have several fields and their setter-getter methods, I need to exchange objects of these classes as a JSONObject via Sockets to and from client and server.
Is there any way I can create JSONObject directly from the object of model class such that fields of the object become keys and values of that model class object become values for this JSONObject.
Example:
Customer c = new Customer();
c.setName("Foo Bar");
c.setCity("Atlantis");
.....
/* More such setters and corresponding getters when I need the values */
.....
And I create JSON Object as:
JSONObject jsonc = new JSONObject(c); //I'll use this only once I'm done setting all values.
Which gets me something like:
{"name":"Foo Bar","city":"Atlantis"...}
Please note that, in some of my model classes, certain properties are itself an object of other model class. Such as:
Product p = new Product();
p.setName("FooBar Cookies");
p.setProductType("Food");
c.setBoughtProduct(p);
In a case like above, as I'd expect, the yielded JSON object would be:
{"name":"Foo Bar","city":"Atlantis","bought":{"productname":"FooBar Cookies","producttype":"food"}}
I know I could create something like toJSONString() in each model class and have the JSON-friendly string created and manipulate it then, but in my previous experiences of creating RESTful service in Java (which is totally out of context for this question), I could return JSON string from the service method by using #Produces(MediaType.APPLICATION_JSON) and have the method returning object of model class. So it produced JSON string, which I could consume at the client end.
I was wondering if it's possible to get similar behavior in current scenario.
Google GSON does this; I've used it on several projects and it's simple and works well. It can do the translation for simple objects with no intervention, but there's a mechanism for customizing the translation (in both directions,) as well.
Gson g = ...;
String jsonString = g.toJson(new Customer());
You can use Gson for that:
Maven dependency:
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.8.0</version>
</dependency>
Java code:
Customer customer = new Customer();
Product product = new Product();
// Set your values ...
Gson gson = new Gson();
String json = gson.toJson(customer);
Customer deserialized = gson.fromJson(json, Customer.class);
User = new User();
Gson gson = new Gson();
String jsonString = gson.toJson(user);
try {
JSONObject request = new JSONObject(jsonString);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Use gson to achieve this. You can use following code to get the json then
Gson gson = new Gson();
String json = gson.toJson(yourObject);
I have used XStream Parser to
Product p = new Product();
p.setName("FooBar Cookies");
p.setProductType("Food");
c.setBoughtProduct(p);
XStream xstream = new XStream(new JettisonMappedXmlDriver());
xstream.setMode(XStream.NO_REFERENCES);
xstream.alias("p", Product.class);
String jSONMsg=xstream.toXML(product);
System.out.println(xstream.toXML(product));
Which will give you JSON string array.