Convert JSON array[array[String]] to Java array - java

I have a JavaScript JSON array[array[String]] called jsonArray in my JSP1.jsp.
I am converting jsonArray to a String jsonArrayStr using JSON.stringify(jsonArray) in JSP1.jsp.
I am passing jsonArrayStr as a parameter while calling another JSP JSP2.jsp this way-
"JSP2.do?jsonArrayStr="+jsonArrayStr
In JSP2.jsp, I am doing this-
String jsonArrayStr = request.getParameter("jsonArrayStr");
Now how do I convert jsonArrayStr to Java array (JSP2.jsp doesn't contain any JavaScript code)
Summary-
I have a JavaScript JSON Array in a JSP1.jsp, which I want to access as a normal Java array/arraylist in JSP2.jsp. How do I achieve this?


OK, so you have a two-dimensional array of strings represented as a JSON like this stored in a Java String:
[["a", "b", "c"],["x"],["y","z"]]
You need to somehow parse or "deserialize" that value into a Java String[][]. You can use a library like from http://www.json.org/java/index.html or http://jackson.codehaus.org/ or you can try to do it manually. Manually could be a little tricky but not impossible. The json.org library is very simple and might be good enough. The code would be something like this (I haven't tried/tested this):
JSONArray jsonArray = new JSONArray(jsonArrayStr); // JSONArray is from the json.org library
String[][] arrayOfArrays = new String[jsonArray.length()][];
for (int i = 0; i < jsonArray.length(); i++) {
JSONArray innerJsonArray = (JSONArray) jsonArray.get(i);
String[] stringArray = new String[innerJsonArray.length()];
for (int j = 0; j < innerJsonArray.length(); j++) {
stringArray[j] = innerJsonArray.get(j);
}
arrayOfArrays[i] = stringArray;
}


somethingk like this
ArrayList<String> strings= new ArrayList<String>();
JSONArray jsonArray = (JSONArray)jsonObject;
if (jsonArray != null) {
int len = jsonArray.length();
for (int i=0;i<len;i++){
list.add(jsonArray.get(i).toString());
}
}
String[] Stringarray = strings.toArray(new String[strings.size()]);

Related

Json object to java arraylist

I have pass two values from ajax to my servlet.
I used
JsonObject data = new Gson().fromJson(request.getReader(), JsonObject.class);
System.out.println(data);
and this is the output
{"0":"31/01/2017","1":"19/01/2017"}
Now I want to convert this data into a java arraylist but not really sure how.
I tried
Gson googleJson = new Gson();
JsonObject data = googleJson.fromJson(request.getReader(), JsonObject.class);
System.out.println(data);
JsonArray jsonArr = data.getAsJsonArray();
// jsonArr.
ArrayList jsonObjList = googleJson.fromJson(jsonArr, ArrayList.class);
for(int i=0; i< jsonObjList.size(); i++) {
System.out.println(jsonObjList.get(i));
}
But got an error
java.lang.IllegalStateException: This is not a JSON Array.
Someone help me please? thanks.

Create instance of JsonArray then add json element to that array using key.
Here is your solution :
Gson googleJson = new Gson();
JsonObject data = googleJson.fromJson(request.getReader(), JsonObject.class);
System.out.println(data);
JsonArray jsonArr = new JsonArray();
for(Entry<String, JsonElement> entry : data.entrySet()) {
jsonArr.add(data.get(entry.getKey()));
}
ArrayList jsonObjList = googleJson.fromJson(jsonArr, ArrayList.class);
for(int i = 0; i < jsonObjList.size(); i++) {
System.out.println(jsonObjList.get(i));
}

For a Json to be a valid JsonArray object you should have it to a proper format. Can you change your json string return from your ajax? If yes you should change it to something like this:
Gson googleJson = new Gson();
JsonObject data = googleJson.fromJson("{test: [{\"0\":\"31/01/2017\"},{\"1\":\"19/01/2017\"}]}", JsonObject.class);
System.out.println(data);
JsonArray jsonArr = data.getAsJsonArray("test");
ArrayList jsonObjList = googleJson.fromJson(jsonArr, ArrayList.class);
for(int i=0; i< jsonObjList.size(); i++) {
System.out.println(jsonObjList.get(i));
}
If not you should parse it by your self and convert it to everything you want.

Retrieving a Json String using the correct library

I'm trying to get the content of msg which is ERROR. I'm doing that by transforming string return into an array.
Now the solution 1, works perfectly fine using import org.json.JSONArray;:
Vector<ClsReturn> ret = null;
ret = ds.ind(coll,uri );
JSONArray array = new JSONArray(" [{\"type\":1, \"txt\":\"ERROR\"}]");
int i = 0;
JSONObject myJsonObject = new JSONObject();
while(i < array.length()){
myJsonObject = array.getJSONObject(i);
System.out.println(myJsonObject.getString("txt"));
i++;
}
The above solution allows me tro retrieve the content of "txt", which is "ERROR".
However (below code) when I try to use the reutrn of String jsReturn = JSONArray.toJSONString(ret); I'm not capable to do that because the library I'm using doesn't support JSONArray.toJSONString, so I need to import org.json.simple.JSONArray; which in turn doesn't allow me to use array.getJSONObject(i) but both libraries org.json.simple.JSONArray and
org.json.JSONArray don't work together. Any workaround to get the desired outcome?
Vector<ClsReturn> ret = null;
ret = ds.ind(coll,uri );
String jsReturn = JSONArray.toJSONString(ret);//output(using simple.JSONArray) --> [{"type":1, "msg":"ERROR"}]
JSONArray array = new JSONArray(jsReturn);
int i = 0;
JSONObject myJsonObject = new JSONObject();
while(i < array.length()){
myJsonObject = array.getJSONObject(i);
System.out.println(myJsonObject.getString("txt"));
i++;
}

org.json.JSONArray has a toString() method that will output a JSON string. It also allows for indentation by using toString(int indent_factor)

What should i use to store multiple images?

What should i use to store multiple images that i retrieve from for loop? array or list? Is there any example functions that i can use? Below is my example for loop where i get my data.
JSONObject mainObject = new JSONObject(response.toString());
JSONArray uniObject = mainObject.getJSONArray("result");
for(int i = 0; i < uniObject.length(); i++) {
JSONObject rowObject = uniObject.getJSONObject(i);
co.img1 = ipAddress +"img/store/" + rowObject.getString("store_banner");
}

Use ArrayList<>(); It's away more flexible than the normal array;

How to store Json Array to Java ArrayList?

I am completely don't know Json. Now i am working in Android project. I know how to use ArrayList. I have Json file inside of my Asset folder in my Android Project.
So, now i need How to parse this file from assets folder and how to store it to ArrayList.

String json="Your Json";
JSONObject resultJson = new JSONObject(json);
JSONArray value = resultJson.getJSONArray(<Pass Your JsonOject Key here>);
ArrayList<String> list = new ArrayList<>();
for (int i = 0; i < value.length(); i++)
{
JSONObject qstnArray = value.getJSONObject(i);
list.add(qstnArray.getString("question"));
}

Server Response (JSON Format) to Array Conversion

I am working on an android app in which i send an http response to a server and get a response in string which is in JSON format, now on the basis of this response i need to generate a stacked column chart using AChartEngine for different equipments. The response string looks like as follows
[{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":0,"EquipmentDescription":"MTConnect","EquipmentId":5,"EquipmentName":"MTC 1","EquipmentStatusColor":null,"EquipmentStatusDescription":null,"EquipmentStatusId":0,"EquipmentStatusIdentifier":null,"EquipmentStatusTypeId":0,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":null,"EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":[{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":561.60722222222023,"EquipmentDescription":"MTConnect","EquipmentId":5,"EquipmentName":"MTC 1","EquipmentStatusColor":"#008000","EquipmentStatusDescription":"In Cycle","EquipmentStatusId":0,"EquipmentStatusIdentifier":null,"EquipmentStatusTypeId":1,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":"EquipmentStatusTypeName.InCycle","EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":null,"TimeStamp":{"DateTime":"\/Date(-62135596800000)\/","OffsetMinutes":0},"UnknownDowntime_Duration":0,"UnknownDowntime_Percent":0},{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":134.57583333333525,"EquipmentDescription":"MTConnect","EquipmentId":5,"EquipmentName":"MTC 1","EquipmentStatusColor":"#FFFF00","EquipmentStatusDescription":"In Cycle","EquipmentStatusId":0,"EquipmentStatusIdentifier":"","EquipmentStatusTypeId":2,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":"EquipmentStatusTypeName.UnknownDowntime","EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":null,"TimeStamp":{"DateTime":"\/Date(-62135596800000)\/","OffsetMinutes":0},"UnknownDowntime_Duration":0,"UnknownDowntime_Percent":0}],"TimeStamp":{"DateTime":"\/Date(-62135596800000)\/","OffsetMinutes":0},"UnknownDowntime_Duration":0,"UnknownDowntime_Percent":0},{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":0,"EquipmentDescription":null,"EquipmentId":1,"EquipmentName":"PCS Loop 1","EquipmentStatusColor":null,"EquipmentStatusDescription":null,"EquipmentStatusId":0,"EquipmentStatusIdentifier":null,"EquipmentStatusTypeId":0,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":null,"EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":[{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":495.61333333332925,"EquipmentDescription":null,"EquipmentId":1,"EquipmentName":"PCS Loop 1","EquipmentStatusColor":"#008000","EquipmentStatusDescription":"In Cycle","EquipmentStatusId":0,"EquipmentStatusIdentifier":null,"EquipmentStatusTypeId":1,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":"EquipmentStatusTypeName.InCycle","EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":null,"TimeStamp":{"DateTime":"\/Date(-62135596800000)\/","OffsetMinutes":0},"UnknownDowntime_Duration":0,"UnknownDowntime_Percent":0},{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":200.56972222222623,"EquipmentDescription":null,"EquipmentId":1,"EquipmentName":"PCS Loop 1","EquipmentStatusColor":"#FFFF00","EquipmentStatusDescription":"In Cycle","EquipmentStatusId":0,"EquipmentStatusIdentifier":"","EquipmentStatusTypeId":2,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":"EquipmentStatusTypeNam
Now this is a response for five different equipments and how can i use this JSON string to an array so that i can extract the data of each equipment and send it to AChartEngine for drawing of chart?

You can convert the response string to JSONObject. The response you posted is JSONArray.
JSONArray jsonArray = new JSONArray(responseString);
int size = jsonArray.length();
ArrayList<JSONObject> arrayList = new ArrayList<JSONObject>();
for(int i= 0; i< size; i++) {
JSONObject jsonObject = jsonArray.optJSONObject(i);
// use this jsonObject to get the value by passing the keys.
String value = jsonObject.optString(key);
//here is your array list of jsonobjects
arrayList.add(jsonObject);
}

Use below Code for Pass JsonArray and store Value into ArrayList.
JSONArray jArray = new JSONArray(mRes);
ArrayList<String> array1 = new ArrayList<String>();
for(int i= 0; i< size; i++) {
JSONObject jObject = jArray.getJSONObject(i);
String mValue = jObject.getString("your_json_object_name");
array1.add(mValue);
}

Use Gson api, it allows you to direct mapping of json objects to java objects. check following links for further reference:
http://code.google.com/p/google-gson/
https://sites.google.com/site/gson/gson-user-guide

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