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How to avoid backslashes in GSON JsonObject?

I have a Java POJO
public class TagBean {
private String type;
private String id;
public TagBean(String type, String id) {
this.type = type;
this.id = id;
}
// getters
// setters
}
I'm building pojo's and adding them to a List, as
....
List<TagBean> channelsList = new ArrayList<>();
List<TagBean> showsList = new ArrayList<>();
for each <business logic> {
if value=channels {
channelsList.add(new TagBean(...));
}
if value=shows {
showsList.add(new TagBean(...));
}
}
Gson gson = new GsonBuilder().create();
JsonObject tjsonObject = new JsonObject();
tjsonObject.addProperty("channels", gson.toJson(channelsList));
tjsonObject.addProperty("shows", gson.toJson(showsList));
JsonObject mainjsonObject = mainjsonObject.add("tags", tjsonObject);
return mainjsonObject;
My output is:
{
"tags": {
"channels": "[{\"type\":\"channel\",\"id\":\"channel\",\"name\":\"Channel\",\"parent\":\"SXM\"}]",
"shows": "[{\"type\":\"shows\",\"id\":\"shows\",\"name\":\"Shows\",\"parent\":\"SXM\"},{\"type\":\"shows\",\"id\":\"howard\",\"name\":\"Howard Stern\",\"parent\":\"shows\"},{\"type\":\"shows\",\"id\":\"howardstern\",\"name\":\"Howard Stern\",\"parent\":\"howard\"}]",
"sports": "[]"
}
}
How can i remove the backslashes? So the output is like:
{
"tags": {
"channels": " [{"type":"channel","id":"channel","name":"Channel","parent":"SXM"}]",
"shows": "[{"type":"shows","id":"shows","name":"Shows","parent":"SXM"},{"type":"shows","id":"howard","name":"Howard Stern","parent":"shows"}....
There were few other posts, but none explained this.

The problem is caused by this:
tjsonObject.addProperty("channels", gson.toJson(channelsList));
What that is doing is converting channelsList to a string containing a representation of the list in JSON, then setting the property to that string. Since the string contains JSON meta-characters, they must be escaped when the strings are serialized ... a second time.
I think that you need to do this instead:
tjsonObject.add("channels", gson.toJsonTree(channelsList));
That should produce this:
{
"tags": {
"channels":
[{"type":"channel","id":"channel","name":"Channel","parent":"SXM"}],
"shows":
[{"type":"shows","id":"shows","name":"Shows","parent":"SXM"},
{"type":"shows","id":"howard","name":"Howard Stern","parent":"shows"}
....
That is slightly different to what your question asked for, but it has the advantage of being syntactically valid JSON!

String mainJsonStr = mainjsonObject.toString();
mainJsonStr = mainJsonStr.replace("\\\\", ""); //replace the \
System.out.println(mainJsonStr);

The problem is that gson.toJson returns a String, and
tjsonObject.addProperty("channels", gson.toJson(channelsList));
this will add channels as a string and not as a JSON object.
One possible solution is to convert the string returned from gson.toJson to JSON object first then add it to the parent JSON object like
Gson gson = new GsonBuilder().create();
JsonObject tjsonObject = new JsonObject();
tjsonObject.put("channels", new JsonObject(gson.toJson(channelsList)));
tjsonObject.put("shows", new JsonObject(gson.toJson(showsList)));
this will treat channels and shows as JSON object

All strings in java have to escape quotes in them. So jsonInString should have slashes in it. When you output jsonInString though it shouldn't have the quotes. Are you looking at it in a debugger or something?
Just parse json directly and check - will get the output

above solution is not working anymore since GSON 2.8.*
use gson.toJsonTree(jsonText).getAsString(); instead

How to convert this json String to normal java arraylist using gson

I tried to convert following JSON string into Array and got following error:
Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError:
org/apache/commons/logging/LogFactory at
net.sf.json.AbstractJSON.(AbstractJSON.java:54) at
net.sf.json.util.CycleDetectionStrategy.(CycleDetect‌​ionStrategy.java:36)
at net.sf.json.JsonConfig.(JsonConfig.java:65) at
net.sf.json.JSONSerializer.toJSON(JSONSerializer.java:84)
JSON:
[
{
"file_name":"1.xml",
"file_ext":"application/octet-stream",
"sr_no":"0.1",
"status":"Checked ",
"rev":"1",
"locking":"0"
},
{
"file_name":"2.xml",
"file_ext":"json/octet-stream",
"sr_no":"0.2",
"status":"Not Checked ",
"rev":"2",
"locking":"1"
},
{
"file_name":"3.xml",
"file_ext":"application/json-stream",
"sr_no":"0.3",
"status":"Checked ",
"rev":"1",
"locking":"3"
},
{
"file_name":"4.xml",
"file_ext":"application/octet-stream",
"sr_no":"0.4",
"status":"Checked ",
"rev":"0.4",
"locking":"4"
}
]
Code:
JSONArray nameArray = (JSONArray) JSONSerializer.toJSON(output);
System.out.println(nameArray.size());
for(Object js : nameArray)
{
JSONObject json = (JSONObject) js;
System.out.println("File_Name :" +json.get("file_name"));
}

I know the question is about converting JSON String to Java Array, but I would like to also answer about how to convert the JSON String to an ArrayList using the Gson Library.
Since I spend a good amount of time in solving this, I hope my solution may help others.
My JSON string looks similar to this one -
I had an object named StockHistory, and I wanted to convert this JSON into an ArrayList of StockHistory.
This is how my StockHistory class looked -
class StockHistory {
Date date;
Double open;
Double high;
Double low;
Double close;
Double adjClose;
Double volume;
}
The code that I used to convert the JSON Array to the ArrayList of StockHistory is as follows -
Gson gson = new Gson();
Type listType = new TypeToken< ArrayList<StockHistory> >(){}.getType();
List<StockHistory> history = gson.fromJson(reader, listType);
Now if you are reading your JSON from a file, the reader's initialization would be -
Reader reader = new FileReader(fileName);
and if you are just converting a string to JSON object then, the reader's initialization would simply be -
String reader = "{ // json String }";
Hope that helps. Cheers!!!

You can create a java class with entities are: file_name, file_ext, sr_no, status, rev, locking in string type.
public class TestJson {
private String file_name, file_ext, sr_no, status, rev, locking;
//get & set
}
}
Then you call:
public static void main(String[] args) {
String json = your json string;
TestJson[] respone = new Gson().fromJson(json, TestJson[].class);
for (TestJson s : respone) {
System.out.println("File name: " + s.getFile_name());
}
}
So, you have a list of object you want.

Firstly I have to say your question is quite "ugly" and next time please improve your question's quality.
Answer:
Try to use com.fasterxml.jackson.databind.ObjectMapper
If you have a java class to describe your items in the list:
final ObjectMapper mapper = new ObjectMapper();
YourClass[] yourClasses = mapper.readValue(YourString, YourClass[].class);
Then convert the array to a List.
If you don't have a java class, just you LinkedHashMap instead.

How to sum up two json values in java android?

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 );
}

How to tokenize Java String with nested square brackets?

I have a string I would like to put into an ArrayList of Strings. The string is basically a JSONObject so I might just be using the wrong methods.
The way the string looks is:
String all = "{"users":
[
[{"login":"username1"},{"password":"test1"},{"index":"1"}],
[{"login":"username2"},{"password":"test2"},{"index":"2"}]
]}";
All I want is the JSONObject values so my pattern gives me this String:
String part = "[
[{"login":"username1"},{"password":"test1"},{"index":"1"}],
[{"login":"username2"},{"password":"test2"},{"index":"2"}]
]";
This is what I want:
user[0] = "[{"login":"username1"},{"password":"test1"},{"index":"1"}]";
user[1] = "[{"login":"username2"},{"password":"test2"},{"index":"2"}]";
When I try to group everything in between the inner [ ] it just returns everything in the outer [ ].
I have tried:
String[] user = new String[20];
Pattern p = Pattern.compile("(\\[\\{.*\\}\\])");
Matcher m = p.matcher(part);
while(m.find()){
user = m.group().split("\\],\\[");
}
This approach gets rid of the ],[ which I'm using as a delimiter.

Class User {
private String username;
private String password;
}
Class Users{
LinkedList<User> users;
}
You can use any available JSON marshallers like Jackson etc to deserialize the string into a Users.

So I took the advice from the comment section and sure enough using JSON methods was the way to go. I would still like to see if it was possible to accomplish with regular expressions.
ArrayList<String> myList = new ArrayList<String>();
JSONObject obj = new JSONObject();
JSONArray arr = new JSONArray();
obj = {"user":"[[{},{},{}],[{},{},{}]]";
// This gives me the outer JSONArray
arr = obj.getJSONArray("user");
// This iterates through the outer JSONArray assigning each inner JSONArray
// to my ArrayList as strings.
for( int i = 0; i < arr.length(); i++){
myList.put(arr.getJSONArray(i).toString());
}

How to append a String to JSON String in java?

I am getting the data from the Zookeeper node like this
byte[] bytes = client.getData().forPath("/my/example/node1");
String ss = new String(bytes);
Here ss will have data like this which is a simple JSON String consisting of key value pair -
{"description":"Some Text", "machinename":"machineA", "ipaddress":"192.128.0.0"}
Now I want to append one more key value pair at the end to the above JSON String. This is the below key value pair I want to append -
"version":"v3"
So the final JSON String will look like this -
{"description":"Some Text", "machinename":"machineA", "ipaddress":"192.128.0.0", "version":"v3"}
What's the best and efficient way to do this?

Use a JSON Parser/Generator to parse your given JSON to a tree structure and then add your JSON field.
With Gson, that would look something like this
Gson gson = new Gson();
JsonObject jsonObject = gson.fromJson(ss, JsonObject.class); // parse
jsonObject.addProperty("version", "v3"); // modify
System.out.println(jsonObject); // generate
prints
{"description":"Some Text","machinename":"machineA","ipaddress":"192.128.0.0","version":"v3"}
Will Zookeeper always return valid JSON or their custom format? Be aware of that.

When it comes to JSON processing, string manipulation only works in special and simple cases. For the general case, a good JSON parser library should be used.
Jackson is among the top of such libraries in terms of performance, efficiency, versatility and reliability, plus it is published under the commercial-friendly Apache 2.0 license.
Following is a simple implementation of the requested answer in Jackson.
public static void main(String[] args)
{
String ss = "{\"description\":\"Some Text\", \"machinename\":\"machineA\", \"ipaddress\":\"192.128.0.0\"}";
System.out.println("JSON string before: " + ss);
try
{
ObjectMapper mapper = new ObjectMapper();
Map<String, String> map = (Map<String, String>)mapper.readValue(ss, Map.class);
map.put("version", "v3");
ss = mapper.writeValueAsString(map);
}
catch (Exception e)
{
e.printStackTrace();
}
System.out.println("JSON string after: " + ss);
}

Basic string manipulation. Insert your additional string before the final close brace }. Make sure to add a comma.
Json objects don't need to be ordered.
String json = "{\"key1\":\"value1\",\"key2\":\"value2\"}";
String json2 = "\"version\":\"v3\"";
json2 = ',' + json2;
String json3 = json.substring(0,json.length()-1) + json2 + json.charAt(json.length()-1);
That should be the simplest, most efficient way, if that's all you need to do.
For additional reading on String manipulation,
http://docs.oracle.com/javase/tutorial/java/data/manipstrings.html