JSONArray jsonArray = (JSONArray) obj;
When I use the above code, it shows the error message:
java.lang.ClassCastException: org.json.simple.JSONObject cannot be cast to org.json.simple.JSONArray
Please anyone suggest any method to overcome this error or any other way to read json value form a file in Java (Desktop application).
Use this for get json value in string format from file
public String loadJSONFromFile() {
String json = null;
try {
InputStream is = getActivity().getAssets().open("yourfilename.json");
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
is.close();
json = new String(buffer, "UTF-8");
} catch (IOException ex) {
ex.printStackTrace();
return null;
}
return json;
}
JsonObject is a child of a JsonArray, so as per my suggestion use like this
final JSONArray jsonArray = new JSONArray();
jsonArray.put(obj); //obj is your JsonObject
and you can get JsonObject from array like
jsonArray.getJSONObject(0); //0 is index of your JsonObject in JsonArray
Hope this help you.
Check the content of the file.
It seems that the content is not an array, but a json object.
Open the file with a text editor. If the content is something like:
{ // First character
... content here
} // Last character
it is an object, if it is similar to
[ // First character
... content here
] // Last character
it is an array.
If you need to read an object you need to change your code as follow:
JSONObject jsonObject = (JSONObject) obj;
JSONArray jsonArray = (JSONArray) obj;
This obj is of JsonObject type, so change that line to
JSONObject jsonObject = (JSONObject)obj;
Related
I get the following JSON:
[
{
"user_id": "someValue"
}
]
It's saved inside a String.
I would like to convert it to a JSONObject which fails (as the constructor assumes a JSON to start with {). As this doesn't seem to be possible I'd like to convert it to a JSONArray. How can I do that with SimpleJson?
JSONParser parser = new JSONParser();
JSONArray array = (JSONArray)parser.parse("[{\"user_id\": 1}]");
System.out.println(((JSONObject)array.get(0)).get("user_id"));
You need to cast to a JSONArray as that is what the string contains.
For your task you could use code as bellow:
String t = "[{\"user_id\": \"someValue\"}]";
JSONParser parser = new JSONParser();
JSONArray obj = (JSONArray) parser.parse(t);
System.out.println(obj.get(0));
And result would be JSONObject.
String actualJsonObject = // assuming that this variable contains actual object what ever u want to pass as per your question says
JSONParser parser = new JSONParser();
JSONArray userdataArray= (JSONArray) parser.parse(actualJsonObject );
if(userdataArray.size()>0){
for (Object user : userdataArray) {
JSONObject jsonrow=(JSONObject)parser.parse(String.valueOf(user));
String User_Id= (String)jsonrow.get("user_Id"); \\ Each User_Id will be displayed.
} else{
System.out.println("Empty Array....");
}
It works for me.
String jsonString = "[{\"user_id\": \"someValue\"}]";
JSONArray jsonArray = new JSONArray();
JSONParser parser = new JSONParser();
try {
jsonArray = (JSONArray) parser.parse(js);
} catch (ParseException e) {
e.printStackTrace();
}
I'm learning how to work with JSON's in java and I'm having a problem using getString for one of my keys. My code is here:
public static void getJSON(String matchID){
String s = "";
String test = "{\"employees\":[{\"firstName\":\"John\", \"lastName\":\"Doe\"}]}";
try {
JSONObject hi = new JSONObject(test);
JSONArray stuff = hi.getJSONArray("employees");
String[] items = new String[stuff.length()];
items[0] = stuff.getString("firstName");
} catch (JSONException e) {
e.printStackTrace();
}
}
The "getString" is underlined in red, and the "The method getString(int) in the type JSONArray is not applicable for the arguments (String)" I was following an answer to another question word for word almost, and this happens, any advice? Thanks!
EDIT:
I need to get the specifics by name ie. "firstName" because I will be working with thousands of JSONs that each have hundreds of lines.
You need to get the JSOnObject first from the JSONArray(stuff) before you can call getString().
if you want to get the first element in the jsonarray and get its string this is how you would do it
JsonObject obj = stuff.getJsonObject(0);
String name = obj.getString("firstname");
So I figured out my problem, I didn't realize I had an JSONObject first, my apologies. Fixed like this:
JSONObject hi = new JSONObject(test);
JSONArray stuff = hi.getJSONArray("employees");
JSONObject name = stuff.getJSONObject(0);
String[] items = new String[hi.length()];
items[0]=name.getString("firstName");
System.out.println(items[0]);
you can try the simplest way to Parse in JSON
JSONParser parser=new JSONParser();
String s = "{\"employees\":[{\"firstName\":\"John\", \"lastName\":\"Doe\"}]}";
try{
Object obj = parser.parse(s);
JSONArray array = (JSONArray)obj;
System.out.println(array.get(1));
}catch(ParseException pe){
}
I'm trying to parse this following JSON string to java.
{"Stdout":"Hello World\nThis is Sara","Stderr":"exit status 124"}
This string is dynamic and the content can be different as in,
{"Stdout":"Hello World\nThis is Sara","Stderr":""}
or
{"Stdout":"","Stderr":"exit status 124"}
I'm using the following tutorial and instead of the file I'm adding my String in it.
So I created this code to simply print what "Stdout" and "Stderr" have to say:
public void parsed(String str) {
JSONParser parser=new JSONParser();
try {
Object obj = parser.parse(str);
JSONObject jsonObject = (JSONObject) obj;
JSONArray out = (JSONArray) jsonObject.get("Stdout");
Iterator<String> iterator = out.iterator();
while (iterator.hasNext()) {
System.out.println(iterator.next());
}
// loop array
JSONArray err = (JSONArray) jsonObject.get("Stderr");
Iterator<String> iterator2 = err.iterator();
while (iterator2.hasNext()) {
System.out.println(iterator2.next());
}
} catch (ParseException e) {
e.printStackTrace();
}
}
I'm getting the following result. And I have tried each and every possible solution that I found on Stack Overflow and other sites.
java.lang.String cannot be cast to org.json.simple.JSONArray
The conversions of stdout and stderr are wrong. They're both a String instead of a JSONArray. Try this:
Change: JSONArray out = (JSONArray) jsonObject.get("Stdout");
To: String stdout= (String) jsonObject.get("Stdout");
And print that String and see what happens.
I have created a java server which gets HTTP GET request url as
/Star/getDetails?sentMsg=data.requestorName:ABC,data.companyName:EFG,portfolios:
[{name:,placeholder:Portfolio 1,positions:[{ticker:T1234,weight:29.85},
{ticker:T2345,weight:70.15}],active:false}],analyticsDate:20140630}
I have to parse sentMsg parameter such as I am able to read each variable individually. For eg, i should be able to read data.requestorName, companyName. I am not able to find a way to do it.
request.getParameter("sentMsg") always return String.
Tried parsing it through json-simple
JSONParser jp = new JSONParser();
try {
Object obj = jp.parse(sentMsg);
JSONArray ja = (JSONArray)obj;
} catch (ParseException e) {
e.printStackTrace();
}
But this gives parse exception. I have limitation to use json-simple jar only. Any suggestion on how to do it?
Get the paramter sentMsg from HttpRequest object store it into a string. Split from comma i.e. "," and the last second token would be the json string. You can now parse it using Json simple lib and extract values from it.
Provided you have valid JSON like:
private static String jsonString = "[{name : \"stackOverFlow\"}]";
Convert it to JSONArray like:
JSONArray jsonArray = new JSONArray(jsonString );
Then you can get value out of JSONArray by looping through it:
for (int i = 0; i < jsonArray.length(); i++) { //Iterating over mediaArray
JSONObject media = jsonArray.getJSONObject(i);
String nameFromJSON = media.getString("name");
System.out.println("Name = " + nameFromJSON);
}
Output will be:
//Name = stackOverFlow
I'm trying to parse below json file:
{"units":[{"id":42,
"title":"Hello World",
"position":1,
"v_id":9,
"sites":[[{"id":316,
"article":42,
"clip":133904
}],
{"length":5}]
}, ..]}
This is what I have tried:
Object obj = null;
JSONParser parser = new JSONParser();
Object unitsObj = parser.parse(new FileReader("file.json");
JSONObject unitsJson = (JSONObject) unitsObj;
JSONArray units = (JSONArray) unitsJson.get("units");
Iterator<String> unitsIterator = units.iterator();
while(unitsIterator.hasNext()){
Object uJson = unitsIterator.next();
JSONObject uj = (JSONObject) uJson;
obj = parser.parse(uj.get("sites").toString());
JSONArray jsonSites = (JSONArray) obj;
for(int i=0;i<jsonSites.size();i++){
JSONObject site = (JSONObject)jsonSites.get(i); // Exception happens here.
System.out.println(site.get("article");
}
}
The code is not working when I try to parse the inner json array, so I get:
Exception in thread "main" java.lang.ClassCastException: org.json.simple.JSONArray cannot be cast to org.json.simple.JSONObject
The exception is pointing to this line:
JSONObject site = (JSONObject)jsonSites.get(i);
Any help? tnx.
I've found a working code:
JSONParser parser = new JSONParser();
Object obj = parser.parse(content);
JSONArray array = new JSONArray();
array.add(obj);
If you don't need the array (like the author), you can simply use
JSONParser parser = new JSONParser();
Object obj = parser.parse(content);
The first element of the sites array is an array, as you can see indenting the JSON:
{"units":[{"id":42,
...
"sites":
[
[
{
"id":316,
"article":42,
"clip":133904
}
],
{"length":5}
]
...
}
Therefore you need to treat its value accordingly; probably you could do something like:
JSONObject site = (JSONObject)(((JSONArray)jsonSites.get(i)).get(0));
this worked:
System.out.println("resultList.toString() " + resultList);
org.json.JSONObject obj = new JSONObject(resultList);
org.json.JSONArray jsonArray = obj.getJSONArray(someField);
for(int i=0;i<jsonArray.length();i++){
System.out.println("array is " + jsonArray.get(i));
}
JSONObject site=jsonSites.getJSONObject(i) should work out
JSONObject obj=(JSONObject)JSONValue.parse(content);
JSONArray arr=(JSONArray)obj.get("units");
System.out.println(arr.get(1)); //this will print {"id":42,...sities ..}
#cyberz is right but explain it reverse
You can first read the whole content of file into a String.
FileInputStream fileInputStream = null;
String data="";
StringBuffer stringBuffer = new StringBuffer("");
try{
fileInputStream=new FileInputStream(filename);
int i;
while((i=fileInputStream.read())!=-1)
{
stringBuffer.append((char)i);
}
data = stringBuffer.toString();
}
catch(Exception e){
LoggerUtil.printStackTrace(e);
}
finally{
if(fileInputStream!=null){
fileInputStream.close();
}
}
Now You will have the whole content into String ( data variable ).
JSONParser parser = new JSONParser();
org.json.simple.JSONArray jsonArray= (org.json.simple.JSONArray) parser.parse(data);
After that you can use jsonArray as you want.
If you want to re-filter the json data you can use following method. Given example is getting all document data from couchdb.
{
Gson gson = new Gson();
String resultJson = restTemplate.getForObject(url+"_all_docs?include_docs=true", String.class);
JSONObject object = (JSONObject) new JSONParser().parse(resultJson);
JSONArray rowdata = (JSONArray) object.get("rows");
List<Object>list=new ArrayList<Object>();
for(int i=0;i<rowdata.size();i++) {
JSONObject index = (JSONObject) rowdata.get(i);
JSONObject data = (JSONObject) index.get("doc");
list.add(data);
}
// convert your list to json
String devicelist = gson.toJson(list);
return devicelist;
}
JSONObject site = (JSONObject)jsonSites.get(i); // Exception happens here.
The return type of jsonSites.get(i) is JSONArray not JSONObject.
Because sites have two '[', two means there are two arrays here.
use your jsonsimpleobject direclty like below
JSONObject unitsObj = parser.parse(new FileReader("file.json");
JSONObject baseReq
LinkedHashMap insert = (LinkedHashMap) baseReq.get("insert");
LinkedHashMap delete = (LinkedHashMap) baseReq.get("delete");