I'm trying some code where I want to compare strings i've grabbed from json to certain values. However the if statements never trigger. I have confirmed the values of the instances are set properly, and can be printed out.
//MAKING CLASSES
Collection collection = new ArrayList();
Event ev = new Event();
ev.name = "sven";
ev.source = "src10";
Event2 ev2 = new Event2();
ev2.name = "type";
ev2.data = "somedata";
collection.add(ev);
collection.add(ev2);
//MAKING A BUNCH OF CLASSES TO JSON
Gson gson = new Gson();
String json = gson.toJson(collection);
JsonParser parser = new JsonParser();
JsonArray array = parser.parse(json).getAsJsonArray();
//JSON TO JAVA
for (int i = 0; i < array.size(); i++) {
JsonObject nameObject = array.get(i).getAsJsonObject();
String nameString = nameObject.get("name").toString();
if (nameString.equals("sven")) {
System.out.println("this is sven");
Event event = gson.fromJson(array.get(i), Event.class);
}
else if (nameString.equals("type")) {
System.out.println("this is type");
Event2 event2 = gson.fromJson(array.get(i), Event2.class);
}
else{
System.out.println("nothing");
}
}
According Gson API your call to 'nameObject.get("name")' will return JsonElement. This means you should use 'getAsString()' method instead of 'toString()':
String nameString = nameObject.get("name").getAsString();
'toString()' method is designed (in general) for debugging purposes. And should be used very carefully in program logic.
You need to know that the implementation of toString() in JsonElement class is such that it will return the String inclusive of "".
To make it easier to understand look into the following code
JsonObject json = new JsonObject();
json.addProperty("hello", "tata");
System.out.println(json.get("hello").toString()); // Prints "tata"
System.out.println(json.get("hello").getAsString()); // Prints tata
so internally your code is comparing "sven" and sven which will return not equal
Related
Can any one tell me, how to sum two JSON objects values? Say, for an example:
First JSON
{
"json_obj":20,
}
Second JSON
{
"json_obj":40,
}
Here what I wanted is, I'm trying to create one JSON as same as like the above one, but i need to sum up two values of the JSON object "json_obj" and finally need to show it as like the below JSON
Resultant JSON
{
"json_obj":60
}
How to achieve this?
Try this,
JSONObject jsonObject1 = new JSONObject(First_JSON);
JSONObject jsonObject2 = new JSONObject(Socond_JSON);
JSONObject jsonObject3 = new JSONObject();
jsonObject3.put("json_obj", jsonObject1.getInt("json_obj")+jsonObject2.getInt("json_obj"));
Try this:
public String getAddedValues(String firstJson, String secondJson, String key){
JSONObject first = new JSONObject(firstJson);
JSONObject second = new JSONObject(secondJson);
int value = first.getInt(key) + second.getInt(key);
JSONObject output = new JSONObject();
output.put(key, value);
return output.toString();
}
Invoke it passing your json Strings and the "json_obj" String as key.
The idea is that you forst need to convert the json string into a Java object. Then you do your calculations, and finally you create another JSONObject with the result. JSONObject.toString() returns the common String representation you would expect as output :-)
You can try something like that:
public class CalcObj {
public int json_obj;
}
public String sumTwoJsons(String json1, String json2) {
Gson _gson = new Gson();
CalcObj obj1 = _gson.fromJson(json1, CalcObj.class);
CalcObj obj2 = _gson.fromJson(json2, CalcObj.class);
CalcObj objSum = new CalcObj();
objSum.json_obj = obj1.json_obj + obj2.json_obj;
return _gson.toJson(objSum );
}
JSON values that I get from server:
{
"Status":0,
"Message":"",
"Result":{"0B":"S.C. Blue Air","0Y":"FlyYeti","1X":"Branson Air"}
}
Getting the result as 'response' after connection and I am able to show my JSON string results on the screen.
JSONObject json = new JSONObject(response);
String status = json.getString("Status");
String message = json.getString("Message");
String result = json.getString("Result");
responseView.setText("Status" + status+ "Message" + message" + Result" + result);
I am okay the results of "Status" and "Message" but not with "Result" because want to separate "Result" objects as and able use each of them as objects.
For example:
When I type OB in my app, I will get the result S.C. Blue Air
Instead of :
String result = json.getString("Result");
use
if(json.get("Result") instanceof JSONObject){
JSONObject object = (JSONObject) json.get("Result");
//do what you want with JSONObject
String ob = object.get("0B");
}
If you want to store it some way you can put it to Map or create object if always it is same data
You can use some libraries such as Gson (Google) or Moshi (Square)
Those libraries allows you to declare your model as a plain java class (commonly called POJOS) annotated in some way that this libraries bind your properties in the JSON to your java properties.
In your case:
JSON:
{
"Status":0,
"Message":"",
"Result":{"0B":"S.C. Blue Air","0Y":"FlyYeti","1X":"Branson Air"}
}
MODEL:
public class MyCallResponse {
#SerializedName("Status")
int status;
#SerializedName("Message")
String message;
#SerializedName("Result")
Result result;
}
public class Result {
#SerializedName("0B")
String b;
#SerializedName("0Y")
String y;
#SerializedName("0X")
String x;
}
In this case, with Gson you can do:
MyCallResponse response = new Gson().fromJson(json, MyCallResponse.class);
Log.i("Response b", response.result.b);
Look at the documentation for more information about both libraries.
try this :
JSONObject json = new JSONObject(response);
JSONObject resultObj = json.getJSONObject("Result");
String OB = resultObj.getString("OB");
Try this
String base = ""; //Your json string;
JSONObject json = new JSONObject(base);
JSONOBject resultJson = json.getJSONObject("Result");
// Get all json keys "OB", "OY", "1X" etc in Result, so that we can get values against each key.
Set<Map.Entry<String, JsonElement>> entrySet = resultJson.entrySet();
Iterator iterator = entrySet.iterator();
for (int j = 0; j < entrySet.size(); j++) {
String key = null; //key = "OB", "OY", "1X" etc
try {
Map.Entry entry = (Map.Entry) iterator.next ();
key = entry.getKey ().toString ();
//key = "OB", "OY", "1X" etc
}
catch (NoSuchElementException e) {
e.printStackTrace ();
}
if (!TextUtils.isEmpty (key)) {
Log.d ("JSON_KEY", key);
String value = resultJson.getString(key);
//for key = "0B", value = "S.C. Blue Air"
//for key = "0Y", value = "FlyYeti"
//for key = "1X", value = "Branson Air"
}
}
It works with any array with dynamic json key.
Don't forget to accept the answer & upvote if it works.
Is it possible to change the name of a Json property without serialization with Gson? For example, given this Json
{
"1": {
...
},
"2": {
...
}
}
could I change the "1" to a "3" without removing its contents. I know that the addProperty method adds a new property, or overwrites an existing property with a new value, but I want to change the name of a property without affecting its value. Also, pasting the existing value as the second argument of addProperty will not suffice.
EDIT: To add more context, I will explain the bigger picture. I have a JSON string that is a couple thousand lines long. I'm writing a program leveraging Gson in order to change the values in that JSON string. I am at a point where I not only want to change the values of properties, but the names of the properties themselves. I have done everything so far without serialization.
Here is a snippet of the Java I wrote:
String file = "\\temp.json";
FileReader reader = new FileReader(file);
JsonStreamParser parser = new JsonStreamParser(reader);
// Parse entire JSON
JsonElement element = parser.next();
// Get root element
JsonObject sites = element.getAsJsonObject();
// Get first child element
JsonObject site1 = sites.getAsJsonObject("1");
JsonObject clust1 = site1.getAsJsonObject("CLUST");
for(int i = 1; i < 12; i++) {
// "Dynamic" variable
String num = Integer.toString(i);
// Get property whose name is a number, has siblings
JsonObject one = custCluster1.getAsJsonObject(num);
one.getAsJsonObject().addProperty("name", "cluster" + i);
JsonObject subOne = one.getAsJsonObject("SUB");
subOne.getAsJsonObject().addProperty("name", "aName" + i);
for(int n = 1; n < 1002; n++) {
// "Dynamic" variable
String inst = Integer.toString(n);
// Get property whose name is a number, has siblings
JsonObject subSub = subOne.getAsJsonObject(inst);
// If the property doesn't exist, then don't execute
if(subSub != null) {
JsonArray subSubArray = subSub.getAsJsonArray("SUBSUB");
subSub.getAsJsonObject().remove("name");
int m = 0;
while(m < subSubArray.size()) {
subSubArray.get(m).getAsJsonObject().remove("SR");
subSubArray.get(m).getAsJsonObject().remove("FI");
subSubArray.get(m).getAsJsonObject().remove("IND");
subSubArray.get(m).getAsJsonObject().addProperty("ST", "1");
subSubArray.get(m).getAsJsonObject().addProperty("ID", "2");
subSubArray.get(m).getAsJsonObject().addProperty("DESCR", "hi");
m++;
}
m = 0;
}
}
}
Thanks to #mmcrae for helping and suggesting this method.
Since I'm already saving the (key, value) pairs in variables, you can remove the property whose name you want to change from the parent, and then add it back with a new name and the content that was already saved.
Like this:
JsonObject sites = element.getAsJsonObject();
JsonObject site1 = sites.getAsJsonObject("1");
JsonObject clust1 = site1.getAsJsonObject("CLUST");
site1.remove("CLUST");
site1.add("NEWCLUST", clust1);
We have a requirement to update the JSON data in middle and need to return the updated JSON data using java. Also it should support any type of JSON data.
ex:
Assume {object:{"color":"red","shape":"Triangle"}} is the JSON data and in this we need to update the shape value to Rectangle and we need to return the updated JSON data as below:
{object:{"color":"red","shape":"Rectangle"}}
For this we need to pass the element path ( which element we need to update) and updateText and JSON Data to the JAVA code.
here is the methodCall:
updateValue("object/shape", "Rectangle", "{object:{"color":"red","shape":"Triangle"}}")
We tried below code using Gson library. But with this code we are able to update the targeted Json element, but the requirement is to return the entire JSON data with the updated value.
So please suggest how do we re-build the JSON data with the updated text.
Below is the code we tried to update the Json Data.
public String updateValue(String keyPath, String updateText, String jsonText) {
String[] keys = keyPath.split("/");
JsonParser jsonParser = new JsonParser();
JsonObject jsonObject = (JsonObject) jsonParser.parse(jsonText);
String result = "";
for(String key : keys)
{
if (jsonObject.get(key) instanceof JsonObject)
{
jsonObject = (JsonObject)jsonObject.get(key);
}
else if(jsonObject.get(key) instanceof JsonArray)
{
JsonArray jsonArray = (JsonArray)jsonObject.get(key);
result = jsonArray.toString();
}
else
{
result = jsonObject.get(key).toString();
}
}
result = result.replace(result, updateText);
return result;
}
The problem lies in the way you do the replacements. When you translate the JsonObject to String, you lose the object, and after replacement, you just have the replaced String. To fix it, you need to operate directly on the object, instead of the String counterpart. Because JsonObject is mutable, holding a reference to the input will reflect the changes. One drawback is you can't replace a value in a JsonArray this way, partly because you don't know which element to replace. To accomplish that, you will need a little more in the input(either the value to replace or the element position).
public String updateValue(String keyPath, String updateText, String jsonText) {
String[] keys = keyPath.split("/");
JsonParser jsonParser = new JsonParser();
JsonObject jsonObject = (JsonObject) jsonParser.parse(jsonText);
JsonObject returnVal = jsonObject; // This holds the ref to target json object
JsonPrimitive jp = new JsonPrimitive(updateText);
String finalKey = keys[keys.length - 1];
for(String key : keys)
{
if (jsonObject.get(key).isJsonObject())
{
jsonObject = (JsonObject)jsonObject.get(key);
}
}
jsonObject.remove(finalKey);
jsonObject.add(finalKey, jp);
return returnVal.toString();
}
You can use JsonPath lib for that and try using the following code.
private static final Configuration configuration = Configuration.builder()
.jsonProvider(new JacksonJsonNodeJsonProvider())
.mappingProvider(new JacksonMappingProvider())
.build();
JsonNode updatedJson = JsonPath.using(configuration).parse(originaljson)
.set("use the path to go for value", "new value").json();
json = updatedJson.toString();
i want to create a Json like this
[{"sID":"221","mID":"0"},
{"sID":"222","mID":"11"},
{"sID":"223","mID":"11"}]
i have tried below code but that create Json just only for one line
JSONObject json = new JSONObject();
JSONObject manJson = new JSONObject();
manJson.put("sID", "23");
manJson.put("mID", "111");
json.put("",manJson);
this above code create Json like this
{"":{"sID":"23","mID":"111"}}
Please let me know about the changes required in that Java code thanks.
Change your code as:
JSONArray jsonArray = new JSONArray();
//Add 1st JSONObject to JSONArray
JSONObject jsonObjone = new JSONObject();
jsonObjone.put("sID", "221");
jsonObjone.put("mID","0");
jsonArray.put(jsonObjone.toString();
//Add 2nd JSONObject to JSONArray
JSONObject jsonObjtwo = new JSONObject();
jsonObjtwo.put("sID", "222");
jsonObjtwo.put("mID","11");
jsonArray.put(jsonObjtwo.toString());
//Add 3rd JSONObject to JSONArray
JSONObject jsonObjthrd = new JSONObject();
jsonObjthrd.put("sID", "223");
jsonObjthrd.put("mID","11");
jsonArray.put(jsonObjthrd.toString());
Use toJSONArray() method on manjson.
I recommend the jackson library it makes things very easy. To use it you would have an object like this...
class Ids {
private int Sid;
private int Mid;
public setSid(int Sid) {
this.Sid = Sid;
}
public setMid(int Mid) {
this.Mid = Mid;
}
public getSid() {
return Sid;
}
public getMid() {
return Mid;
}
}
Then you can use the objectMapper from the library to go from an array that you have in memory to a json String like so
Ids[] idsArray = new Ids[2];
//add ids object to array
String jsonString = objectMapper.writeValueAsString(idsArray);
Of course doing it this way depends on how your ids are stored but for me it generally makes my code a lot cleaner and the Jackson Library is pretty good performance wise.