JSON: parsing with java and org.json (recursion) - java

I'm using the package org.json to parse a JSONArray (I have the json strings saved in a database). However, I don't succeed in parsing it when the same key could have associated a String or a JSONObject, depending on the context.
For example, see the following JSON code...
[ { "cssClass" : "input_text",
"required" : "undefined",
"values" : "First Name"
},
{ "cssClass" : "checkbox",
"required" : "undefined",
"title" : "What's on your pizza?",
"values" : { "2" : { "baseline" : "undefined",
"value" : "Extra Cheese"
},
"3" : { "baseline" : "undefined",
"value" : "Pepperoni"
}
}
}
]
In the code above, the key "values" has 2 possibilities...
A String with value "First Name"
A JSONObject with value {"2":{"value":"Extra Cheese","baseline":"undefined"},"3":{"value":"Pepperoni","baseline":"undefined"}}.
How am I able to process this correctly when the value could be 2 different data types?

You'll probably still need to detect whether it is a JSONObject or a String, so that you can process it further, but perhaps something here might help...
You could try something like this...
String cssClass = myJson.getString("cssClass");
if (cssClass.equals("input_text")){
// Read it as a String
String values = myJson.getString("values");
}
else if (cssClass.equals("checkbox")){
// Read it as a JSONObject
JSONObject values = myJson.JSONObject("values");
// further processing here
}
Or maybe something like this...
String cssClass = myJson.getString("cssClass");
String values = myJson.getString("values");
if (cssClass.equals("input_text")){
// do nothing - it's already a String
}
else if (cssClass.equals("checkbox")){
// Parse the String into a JSONObject
JSONObject valuesObject = new JSONObject(values);
// further processing here
}

Think it this way in js or java duplicate variable creation under same scope is invalid,so to avoid ambiguity put them in separate json object with different variable names before putting it to the json array.

Related

JSON parsing help (Native Android, java)

I am trying to do JSON parsing. The JSON data is shown below, I am trying to get the "categories". I was able to JSON parse everything else, but I am not sure what does this "categories" belong to, is it a JSONObject, JSONArray, or something else? I am a newbie and self-taught, usually I am familiar that JSONArray has form of "JSONArray": {["content"]}, and the "content" is JSONObject. But in this case, "categories":["content"]. I am trying to parse this "categories", and turn it to string. Thank you for your help.
{
"results": [
{
"type": "Restaurant",
"id": "jfhuiewjkfkdljiahueijkfnlsdiejkl1484391hjk8421k",
"score": 99.9844207764,
"dist": 15.581982823437135,
"info": "search:ta:840369014527642-US",
"poi": {
"name": "RoofTop Bar",
"categorySet": [
{
"id": 184729472943
}
],
"categories": [
"pub food",
"restaurant"
]}
}]
}
This is what I have tried:
groups = new JSONArray();
groups = response.getJSONArray("results");
if (groups.length() > 0) {
JSONObject resultObject = groups.getJSONObject(0);
if (resultObject.has("poi")) {
if (resultObject.getJSONObject("poi").has("name")) {
nameResult = resultObject.getJSONObject("poi").getString("name");
} else {
nameResult = "Information is not available.";
}
if (resultObject.getJSONObject("poi").has("categories")) {
JSONObject categoriesResult;
categoriesResult = resultObject.getJSONObject("categories").toString();
}
results is an array of objects
The first object contains a property called poi
poi contains a property called categories
So using the top to bottom approach, we can arrive at
const categoriesArray = results[0].poi.categories; // gives categories as an array of strings
const categoriesString = categoriesArray.join(",") // gives categories as string, with comma separated values
I am not sure if it is the actual raw data but the poi object where the categories are contained is malformed. It is missing a closing bracket which could be causing parsing issues.
That apart, the field categories from the poi object is a list of strings I am not sure how you want to format it to a string but you could loop through them and do want you want with them.
In order to obtain them you can access them from your object with results[0].poi.categories or loop through the results before accessing the categories with result.poi.categories where result is the variable containing the currently looped result.
EDIT:
From your code sample, assuming response is a JSONObject you can do the following.
Then to obtain categories in a string without the array format, you can loop through the categories and concatenate them to a string.
String categories = resultObject.get("categories").join(", ");

Reading the array name itself (not its content) from JSON using java

I have a JSON like this -
result = [
{ "value1": [
{
"number" : "3",
"title" : "hello_world"
},
{
"number" : "2",
"title" : "hello_world"
}
]
},
{ "value2": [
{
"number" : "4",
"title" : "hello_world"
},
{
"number" : "5",
"title" : "hello_world"
}
]
}
]
I want to get result[0] i.e "value1" and result[1] i.e "value2".
Below is my code for parsing this Json -
JsonParser jsonParser = new JsonParser();
JsonArray resultArray = jsonParser.parse(result.getAsJsonArray("result"));
Above code is working fine and I am getting 2 Json arrays. Now for getting value1 I have written this code-
String v = resultArray.get(0).getAsJsonObject().get("value1").getAsString();
But this is not giving me value1 rather than its throwing error "java.lang.IllegalStateException". What I am doing wrong here?
Please note that I want to read array name of "value1" and "value2" itself as string and not its inside content.Means print line should print value1 as output.
Value1 is not String but rather a JsonArray,
when you call getAsString() method, it will throw Exception telling you the value is not of a String object.
few Options :
1- read the value as JsonArray then convert it to String using toString method:
String v = resultArray.get(0).getAsJsonObject().getAsJsonArray("value1").toString();
2- use toString method directly on JsonElement itself (return value of get("value1")
String v = resultArray.get(0).getAsJsonObject().get("value1").toString();
I normally use option one because it enforces the check.
EDIT:
After reading comment, basically what is required is to get all the keys of each JsonObject within each Object
you need to loop through the array and get all they entrySet().(not tested but should work)
for(JsonElement element : resultArray){
JsonObject next= element.getAsJsonObject();
for(Map.Entry<String,JsonElement> entry : next.entrySet()){
System.out.println(entry.getKey()); // <-- prints out value1 and value2
}
}

Keep double quotes when getting element from JSONArray

I am using JsonPath to retrieve a value from a JSON file. The JSON file looks something like this:
[
{
"username": "John",
"password": {
"passwordValue": "passwordjohn",
"secret_key": "123"
}
},
{
"username": "Nick",
"password": {
"passwordValue": "XXX",
"secret_key": "ZZZ",
"other_key": "YYY"
}
}
]
The JsonPath I am using is to retrieve the password from a particular user. Example:
fun getPassword() {
val passwords: JSONArray = read(jsonFile, "\$.[?(#.name==\"John\")].password")
}
However, I found two obstacles. Firstly, I get back a net.minidev.json.JSONArray always, and the same path with appended [0] doesn't work.
Therefore, I try to get the only element from the JSONArray I get back, like this: credentials[0]. Unfortunately, this removes the double quotes in the field names, resulting in something like this:
{passwordValue: passwordjohn, secret_key: 123}
Which is impossible to work with.
I am looking for a way to get this back:
{"passwordValue": "passwordjohn", "secret_key": "123"}
What I ended up doing was to remove the [ and ] symbols from the beginning of the JSONArray after converting it to a String:
private fun JSONArray.toCredentialString(): String {
val credentialString = this.toString()
return credentialString.substring(1, credentialString.length - 1)
}
Any better solution is welcome.

How to update .json attribute value converted into string?

I have a JSON file which I read from a location and converted it into string as below i.e. A string variable contains exact same JSON as printed below. For some testing purpose I needed it.
So the thing is that I want to update the value of key "MainId". How do I do that?
Here is mine JSON:
{
"Entity": {
"MainId":"XFG",
"AlternateIdentifiers" : [
{
"Type":{
"Abbreviation":"ReferenceNumber"
},
"Value":"abc"
}
]
}
}
Initialize a JSONObject , you have to import the json.org library , put the json in a string and then in the constructor of JSONObject.
So you can navigate the JSON through this new object.

Parsing nested json array in java

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

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