I want to know if it is possible to check if some key exists in some jsonArray using java. For example: lets say that I have this json string:
{'abc':'hello','xyz':[{'name':'Moses'}]}
let's assume that this array is stored in jsnArray from Type JSONArray.
I want to check if 'abc' key exists in the jsnArray, if it exists I should get true else I should get false (in the case of 'abc' I should get true).
Thnkas
What you posted is a JSONObject, inside which there is a JSONArray. The only array you have in this example is the array 'xyz', that contains only one element.
A JSONArray example is the following one:
{
'jArray':
[
{'hello':'world'},
{'name':'Moses'},
...
{'thisIs':'theLast'}
]
}
You can test if a JSONArray called jArray, included inside a given JSONObject (a situation similar to the example above) contains the key 'hello' with the following function:
boolean containsKey(JSONObject myJsonObject, String key) {
boolean containsHelloKey = false;
try {
JSONArray arr = myJsonObject.getJSONArray("jArray");
for(int i=0; i<arr.length(); ++i) {
if(arr.getJSONObject(i).get(key) != null) {
containsHelloKey = true;
break;
}
}
} catch (JSONException e) {}
return containsHelloKey;
}
And calling that in this way:
containsKey(myJsonObject, "hello");
Using regular expressions will not work because of the opening and closing brackets.
You could use a JSON library (like google-gson) to transform your JSON Array into a java array and then handle it.
JSON arrays don't have key value pairs, JSON objects do.
If you store it as a json object you can check the keys using this method:
http://www.json.org/javadoc/org/json/JSONObject.html#has(java.lang.String)
If you use JSON Smart Library in Java to parse JSon String -
You can parse JSon Array with following code snippet -
like -
JSONObject resultsJSONObject = (JSONObject) JSONValue.parse(<<Fetched JSon String>>);
JSONArray dataJSon = (JSONArray) resultsJSONObject.get("data");
JSONObject[] updates = dataJSon.toArray(new JSONObject[dataJSon.size()]);
for (JSONObject update : updates) {
String message_id = (String) update.get("message_id");
Integer author_id = (Integer) update.get("author_id");
Integer createdTime = (Integer) update.get("created_time");
//Do your own processing...
//Here you can check null value or not..
}
You can have more information in - https://code.google.com/p/json-smart/
Hope this help you...
Related
I'm trying to loop the calls: JSON array and trying to fetch the machine details JSON object which is present under calls JSON array list as like below:
{
"<dynamicValue>":{
"type":"CORR-ID",
"tags":[
{
"name":"9VB6454145983212H",
"flags":[
"FLAG_DYNAMIC_VALUE",
"FLAG_ID_LOOKUP_SUPPORTED"
]
}
],
"callSummary":[
{
"colo":"lvs",
"pool":"amazon_paymentsplatformserv",
"machine":"stage2utb29958"
},
{
"colo":"lvs",
"pool":"amazon_elmoserv",
"machine":"msmamoserv_0"
},
{
"colo":"lvs",
"pool":"amazon_xopaymentgatewayserv",
"machine":"msmastmentgatewayserv_1"
},
{
"colo":"lvs",
"pool":"amazon_paymentapiplatserv",
"machine":"msmaentapiplatserv_2"
},
{
"colo":"lvs",
"pool":"amazon_userlifecycleserv_ca",
"machine":"stage2utb91581"
},
{
"colo":"lvs",
"pool":"amazon_dafproxyserv",
"machine":"msmasfproxyserv_1"
},
{
"colo":"lvs",
"pool":"paymentserv",
"machine":"te-alm-15757_paymentexecutionserv_0",
"calls":[
{
"colo":"lvs",
"pool":"fimanagementserv_ca",
"machine":"msmgementserv_ca_20"
},
{
"colo":"lvs",
"pool":"fimanagementserv_ca",
"machine":"msmasgementserv_ca_4"
}
]
}
]
}
}
The above JSON file which I stored in String variable and trying to fetch the machine details which is under calls: JSON ARRAY by using below code.
Code:
public static void getHttpUrlformachineList(String response, String CalId, String componentName)
throws Exception
{
//System.out.println(response);
Map<String, String> data = new HashMap<String, String>();
JSONParser parser = new JSONParser();
JSONObject object = (JSONObject) parser.parse(response);
JSONObject getValue = (JSONObject) object.get(CalId.trim()); //CalId is the dynamic value that mentioned in the JSON input file
JSONObject getCalSummary = (JSONObject) object.get("callSummary");
JSONArray arrays=(JSONArray) getCalSummary.get("calls");
System.out.println(arrays.size()); // return null pointer
}
Error:
java.lang.NullPointerException: null
at com.online.amazon.hadoop.cal.swagger.utils.Utils.getHttpUrlformachineList(Utils.java:112) ~[classes/:na]
If you notice that calls Array List will not be available in all the callSummary JSON Array, and It will be dynamic and can be available under any component that listed above.
So I just want to dynamically get the calls: JSON array and iterate and fetch machine details.
Can someone help me to achieve this?
Note: I'm using JSON-Simple library to parse and iterate the JSON. It would be great if I get solution on the same.
Updated:
I also tried to create callSummary as JSON array and loop that array to get each JSON object and tried to find the calls but this is also leads to Null pointer.
Also the calls json array is not index specific. It can be anywhere in the payload. It may or may not be there in the payload. I just need to handle if it's exist in any of the component then I need to fetch that machine details
change
JSONArray arrays=(JSONArray) getCalSummary.get("calls");
to
JSONArray arrays= getCalSummary.getJSONArray("calls")
and all other functions where you get objects instead of "get" you should use "getJSONObject", "getString" etc.. then you dont have to cast,
also im pretty sure its not arrays.size() its arrays.length() if you are using package org.json.JSONArray but since key "calls" doesnt exist in every "callSummary" you should check if its null or not before.
You should match the types as specified in your JSON string:
public static void getHttpUrlformachineList(String response, String CalId, String componentName)
throws Exception
{
//System.out.println(response);
Map<String, String> data = new HashMap<String, String>();
JSONParser parser = new JSONParser();
JSONObject object = (JSONObject) parser.parse(response);
JSONObject getValue = (JSONObject) object.get(CalId.trim()); //CalId is the dynamic value that mentioned in the JSON input file
JSONArray getCalSummary = (JSONArray) object.get("callSummary"); // callSummary is a JSONArray, not JSONObject
for (int i = 0; i < getCalSummary.length(); i++) {
JSONObject obj = getCalSummary.getJSONObject(i);
if (obj.has("calls")) {
// grab calls array:
JSONArray callsArray = obj.getJSONArray("calls");
}
}
}
Here, you should also check your JSON values with .has(...) method to avoid getting JSONException if a field doesn't exists in your JSONObject.
I have a very complex json structure. It contains many array elements and those array elements contains other array elements and so on..
Please see below json tree structure.
Json Tree Structure-1 :
Json Tree Structure-2 :
As highlighted above in yellow, I want to update the value of "rdKey" field.
I wrote below code and it is perfectly working fine :
String json = "escaped string (as it's a big string, I can't put it here)";
JSONObject jsonObj = new JSONObject(json);
if (jsonObj.has("responseMap")) {
JSONObject responseMap = jsonObj.getJSONObject("responseMap");
if (responseMap.has("ValueJson")) {
JSONObject valueJson = responseMap.getJSONObject("ValueJson");
if (valueJson.has("ticketBean_CM")) {
JSONObject ticketBean_CM = valueJson.getJSONObject("ticketBean_CM");
if (ticketBean_CM.has("addByGamma")) {
String addByGamma = ticketBean_CM.getString("addByGamma");
System.out.println(addByGamma);
if (addByGamma.equals("VCE")) {
if (responseMap.has("ScreenJson")) {
JSONObject screenJson = responseMap.getJSONObject("ScreenJson");
if (screenJson.has("sections")) {
JSONArray sectionArray1 = screenJson.getJSONArray("sections");
if (sectionArray1.length() > 0) {
JSONObject section0 = sectionArray1.getJSONObject(0);
if (section0.has("sections")) {
JSONArray sectionArray2 = section0.getJSONArray("sections");
if (sectionArray2.length() > 3) {
JSONObject section6 = sectionArray2.getJSONObject(3);
if (section6.has("sections")) {
JSONArray sectionArray3 = section6.getJSONArray("sections");
if (sectionArray3.length() > 1) {
JSONObject section8 = sectionArray3.getJSONObject(1);
if (section8.has("elements")) {
JSONArray elementsArray1 = section8
.getJSONArray("elements");
if (elementsArray1.length() > 0) {
JSONObject elements1 = elementsArray1.getJSONObject(0);
if (elements1.has("elements")) {
JSONArray elementsArray2 = elements1
.getJSONArray("elements");
if (elementsArray2.length() > 4) {
JSONObject elements2 = elementsArray2
.getJSONObject(4);
if (elements2.has("rdKey")) {
System.out.println(
elements2.getString("rdKey"));
elements2.put("rdKey",
"CircuitID(FullPartial)");
System.out.println(
elements2.getString("rdKey"));
System.out.println(jsonObj.toString());
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
I want you guys to help me if there is any better solution for this. Can I do it without traversing the entire json object (till I find the concerned field) ? This solution will not work if json tree structure gets changes, it needs to be static as a success scenario of this code.
Please suggest better solution.
If you want to escape traversing of JSON then you can use JSONPointer, available in same org.json library.
E.g.:
String query = <json_pointer_query to element array>
JSONPointer pointer = new JSONPointer(query);
JSONObject elementsArrayJSON = (JSONObject) pointer.queryFrom(jsonObj);
elementsArrayJSON.put("rdKey","CircuitID(FullPartial)");
JSON Pointer query language can be referred in:
https://www.rfc-editor.org/rfc/rfc6901
Note:
JSON Pointer is pretty basic, it doesn't support wild card. So you need to be sure about element names, otherwise it would throw exception.
If you're flexible on what library to use, maybe the JsonPath will be useful for you.
You can update all "elements" with "rdKey" using the following code:
JsonPath.parse(json).set("$..elements[?(#.rdKey)].rdKey", "CircuitID(FullPartial)").json()
Above is the json response I am receiving from a url. There are repeated json objects in the response at the same level without a parent json array, I believe that these objects should be within a josn array so one can loop through the objects to access their information.
Is it really an error of missing json array? if not then how can be looped through and receive information in such scenario. Thanks for your time and help.
How can be looped through and receive information in such scenario ?
You should use ITERATOR for this case .
FYI
Iterator is a way to traverse the data over the collection objects.
JSONObject jOBJECT = new JSONObject(success);
Iterator iteratorObj = jOBJECT.keys();
while (iteratorObj.hasNext())
{
String getJsonObj = (String)iteratorObj.next();
System.out.println("Key: " + Key + "------>" + getJsonObj); // 78,40,121,132
}
Here is the detailed solution for such pattern of objects in the service response.
https://stackoverflow.com/a/12870643/1925394
this code maybe can help you:
try {
String data="";//this is you json
JSONObject jsonObject=new JSONObject(data);
JSONArray messages = jsonObject.getJSONArray("message");//get a array
//loop the arrat to output
for (int i = 0; i < messages.length(); i++) {
JSONObject msg=messages.getJSONObject(i);
String id= msg.getString("id");
String username= msg.getString("username");
System.out.println("id:"+id+",username:"+username);
}
} catch (JSONException e) {
e.printStackTrace();
}
but,I advise you don't use this in your project, you can consider Gson ,use this you can transfer json to java model,and then it's easy to use.
In my android project, I have an activity in which I want to obtain data from database using a PHP script. I manage the result of the script in this line :
String result = EntityUtils.toString(entity);
I created the jsonObject :
JSONObject jsonObject = new JSONObject(result);
I print this line and get: {"id":"1"}{"id":"2"}{"id":"3"}
But when I do this:
int i;
for(i=0;i<array.length;i++)
{
array[i] = "ID : "+jsonObject.getString("id");
}
I obtain "id : 1" three times, so I think there are some errors in the cycle..
the code of script php is here :
#Get the first row of the results
while ($row = mysqli_fetch_row($data)) {
#Build the result array (Assign keys to the values)
$result_data = array(
'id' =>$row[0],
);
#Output the JSON data
echo json_encode($result_data);
change to:
int i;
for(i=0;i<array.length;i++)
{
jsonObject=array[i];
String s = "ID : "+jsonObject.getString("id");
}
{"id":"1"}{"id":"2"}{"id":"3"}
is no valid code for a single JSON object - see here: JSON syntax.
I can only guess what you try to achieve, but I would guess your intention is to have a JSON array with 3 objects, each having an "id" value. The JSON code for such a structure should look like this:
[{"id":"1"},{"id":"2"},{"id":"3"}]
If you can make "EntityUtils.toString(entity)" to return the above JSON code, the following loop should also work:
JSONArray ja = new JSONArray(result);
for (int i = 0; i < ja.length(); i++) {
JSONObject jsonObject = ja.getJSONObject(i);
System.out.println("ID : "+jsonObject.getString("id"));
}
edit
On a side note: I believe you get the result you describe, because when you call
new JSONObject(result);
where the result is a String that consists of
{"id":"1"}{"id":"2"}{"id":"3"}
then most likely JSONObject stops parsing the JSON code after the first right brace without throwing a parse exception. So it actually only parses the first JSON object and because of this you get "id : 1" three times. Personally I would consider this behavior a bug, so consider reporting it.
I get the following Error when I try to convert a JSON String into a JSONObject.
Value 48.466667|9.883333 at location of type java.lang.String
cannot be converted to JSONObject
The String is valid JSON, I tested it with http://jsonlint.com/
Example:
{"name":"An der Decke","location":"48.412583|10.0385","type":"Virtual","size":null,"status":"Available","difficulty":1,"rating":null,"terrain":1}
The code that produces the exception looks like that:
jsonObject = new JSONObject(result);
jsonArray = new JSONArray();
Iterator<String> iter = jsonObject.keys();
while (iter.hasNext()) {
String key = iter.next();
try {
JSONObject value = (JSONObject) jsonObject.get(key); <---- Exception
jsonArray.put(value);
} catch (JSONException e) {
// Something went wrong!
}
}
Is the pipe | symbol not a valid character in Java JSON?
EDIT:
The thing is, it works fine if the JSON String doesn't include the "location":"48.412583|10.0385" part...
You seem to misunderstand how the org.json library works.
As explained on the JSON homepage, a JSON value can be a string, number, object, array, true/false or null. The library maps these value types to String, Number subclasses, JSONArray, JSONObject, Boolean or null.
Not everything in that library is a JSONObject. In fact, a JSONObject is specifically used to represent a name/value pair object. JSONObject.get() can potentially return any of the aforementioned value types, that's why it needs to fall back to the greatest common denominator type: Object (and not JSONObject). Thus, casting everything to a JSONObject won't work.
It's your responsibility to ensure that you're casting to the correct type using your knowledge of the incoming data structure. This seems to be a problem in your case: your JSON string contains strings (for name, location, type and status), integers (for difficulty and terrain) and nulls (for size). What exactly are you trying to do with these?
If your goal is just to get a JSONArray of all your JSON string values, there's a much simpler way to do it.
JSONObject jsonObject = new JSONObject(result);
JSONArray jsonArray = jsonObject.toJSONArray(jsonObject.names());
System.out.println(jsonArray); // prints:
// [1,"Available","48.412583|10.0385","An der Decke",1,null,"Virtual",null]
With that aside, you were wrong to assume that every value encapsulated within JSON would be a JSON object itself. In fact, in your case none of them are. The correct types of all the values in your JSON are
// String
System.out.println(jsonObject.getString("name")); // An der Decke
System.out.println(jsonObject.getString("location")); // 48.412583|10.0385
System.out.println(jsonObject.getString("type")); // Virtual
System.out.println(jsonObject.getString("status")); // Available
// Null
System.out.println(jsonObject.isNull("size")); // true
System.out.println(jsonObject.isNull("rating")); // true
// Integer
System.out.println(jsonObject.getInt("terrain")); // 1
System.out.println(jsonObject.getInt("difficulty")); // 1
On the other hand, if your name was an embedded JSON object consisting of first, middle and last names, your JSON string (ignoring the rest of the keys for brevity) would have looked like
{"name": {"fname" : "An", "mname" : "der", "lname" : "Decke"}}
Now, we can put getJSONObject() to use because we really do have an embedded JSON object.
JSONObject jsonObj = new JSONObject("{\"name\":
{\"fname\" : \"An\", \"mname\" : \"der\", \"lname\" : \"Decke\"}}");
// get embedded "name" JSONObject
JSONObject name = jsonObj.getJSONObject("name");
System.out.println(name.getString("fname") + " "
+ name.getString("mname") + " "
+ name.getString("lname")); // An der Decke
The get() method of JSONObject returns a result of type Object. In this case, it seems it is a String. It's as if you were doing
JSONObject value = (JSONObject) new String("asdasdsa");
which obviously makes no sense as they are incompatible types.
Instead, retrieve the value, create a JSONObject from it and add it to the JSONArray.