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How to get value from json object with java obect mapper

I want to get the value at the field first inside name.
How i can access in this field using HashMap in java
{ "payload":{
"name": {
"first": "jean",
"last": "bob,
},
"address": {
"code": "75",
"city": "paris",
"country": "France"
},
}}

Use one of the available Java libraries for handling JSON. E.g. Gson from Guava API. They are pretty straing fw.

Parse json response of rest API and delete certain jsonObjects - JAVA

I have a json file as below which I am getting as a response from rest API:
{
"label": " MARA LEYZIN",
"ClassCode": "PROFESSIONAL",
"actvFlg": "A",
"name": "MARA LEYZIN",
"Typ": {
"label": "C_TYP_LU",
"TypCode": "PROFESSIONAL "
},
"Address": {
"link": [],
"firstRecord": 1,
"pageSize": 10,
"searchToken": "multi",
"item": [
{
"label": "Address",
"addrTypFk": {
"label": "C_ADDRESS_TYPE_LU",
"addrTypCd": "INDUSTRY",
"addrTypDesc": "Industry"
}
}
]
}
I am trying to parse this in Java and to remove some unwanted json objects. Like I want the following string to be replaced by blank:
"link": [],
"firstRecord": 1,
"pageSize": 10,
"searchToken": "multi",
"item":
To achieve this I am trying the following approach:
String jsonStr = new String(Files.readAllBytes(Paths.get(inputFile)));
System.out.println(jsonStr);
jsonStr.replaceAll("link", "");
But it is not replacing the required string with blanks. Please help me in this.

string object is immutable , so basically if do you want to replace something
System.out.println(jsonStr.replaceAll("link", "")); this will print the replaced string but it will not affect the original string, however if you do this
jsonStr=jsonStr.replaceAll("link", "");
System.out.println(jsonStr); this will print the replaced string

First of all:
Your JSON is not validate. You're missing a closing curly bracket at the end of it.
{
"label": " MARA LEYZIN",
"ClassCode": "PROFESSIONAL",
"actvFlg": "A",
"name": "MARA LEYZIN",
"Typ": {
"label": "C_TYP_LU",
"TypCode": "PROFESSIONAL "
},
"Address": {
"link": [],
"firstRecord": 1,
"pageSize": 10,
"searchToken": "multi",
"item": [{
"label": "Address",
"addrTypFk": {
"label": "C_ADDRESS_TYPE_LU",
"addrTypCd": "INDUSTRY",
"addrTypDesc": "Industry"
}
}]
}
}
Second of all you should just change order of your commands to this:
jsonStr.replaceAll("link", "");
System.out.println(jsonStr);
Important addition:
And I would suggest you to use org.json library or even better JACKSON to parse JSON files.
Here's tutorial how to use jackson and it's my warmest suggestion.
You will save a lot of time and you can do whatever you like.

How can I cast json recursively using gson.fromjson

Given I have the following json structure:
{
"Role": {
"id": "5",
"name": "bb1",
"description": "desc1",
"PermissionDeck": [
{
"id": "7",
"Permission": [
{
"id": "398"
},
{
"id": "399"
},
{
"id": "400"
},
{
"id": "401"
},
{
"id": "402"
}
],
"Limit": [
{
"id": "4"
},
{
"id": "5"
}
]
}
]
}
}
If I want to cast this into a LinkedTreeMap result so that its content could be a retrieved by:
result.get("Role") returns Map
and
result.get("Role").get("PermissionDeck").size() == 5
and
result.get("Role").get("PermissionDeck").get(0).get("id") == 398
basically makes gson.fromjson recursively go into the structure, and fold any nested structure into LinkedTreeMap until it gets to the most inner layer, which then gets into LinkedTreeMap
Is this possible without writing custom recursive methods?

You can't. The closest you'll get is with JsonObject and using the appropriate getter for each nested member. In other words, your code needs to be explicit about what it expects in the JSON.
For example
JsonObject result = new Gson().fromJson(theJson), JsonObject.class);
System.out.println(result.getAsJsonObject("Role").getAsJsonArray("PermissionDeck").size());
will print 1 since you only have one element in the JSON array named PermissionDeck in the JSON object named Role in the root JSON object.

Ignore Null Value Fields From Rest API Response Java

In my project when i send Rest Response to Advance Rest Client It only shows Fields which Have some values and Ignores(Does not show) fields which have NULL Values or Empty values.
Part Of Code:
Gson gson=new Gson();
// firstResponse is Object which contains the values
String jsonString = gson.toJson(firstResponse);
test.saveJson(jsonString); //OR System.out.println(jsonString);
return Response.ok(firstResponse).build(); // Response to Rest Client
Response sample To return Response.ok(firstResponse).build();
Advance rest client From web project :
{
"Name": "smith",
"Properties": {
"propertyList": [
{
"ID": "072",
"Number": "415151",
"Address": "Somewhere"
},
{
"ID": "151",
"Number": "a800cc79-99d1-42f1-aeb4-808087b12c9b",
"Address": "ninink"
},
{
"ID": "269",
},
],
},
}
Now when i save this as Json String in DB or When i want to Print this to console it also prints the fiels with null or empty values:
{
"Name": "smith",
"Properties": {
"propertyList": [
{
"ID": "072",
"Number": "415151",
"Address": "Somewhere"
},
{
"ID": "151",
"Number": "a800cc79-99d1-42f1-aeb4-808087b12c9b",
"Address": "ninink"
},
{
"ID": "269",
"Number": "",
"Address": ""
},
],
},
"resultList" :[]
}
How can i print or save this JSON string same as response in rest client i.e. i dont want to print null or empty value field i just want to ignore them.

in top og entity class , try with the annotation
#JsonInclude(Include.NON_EMPTY)
this annotation don't show any empty field in your json.

Not giving you a code but here are some pointers for you:
Read the manual: How to handle NULL values
You may need to use a custom exclusion strategy
Also read this Q&A: Gson: How to exclude specific fields from Serialization without annotations

Converting csv row to JSON object in Java

I've a csv file something similar to this
"name.firstName","name.givenName","name.DisplayName","phone.type","phone.value"
"john","maverick","John Maverick","mobile","123-123-123"
"jim","lasher","Jim Lasher","mobile","123-123-123"
I want to convert the 2nd and 3rd row into JSON objects.Using the first row as Header. So the result will be
[
{
"name": {
"firstName": "john",
"givenName": "maverick",
"DisplayName": "John Maverick"
},
"phone": {
"type": "mobile",
"value": "123-123-123"
}
},
{
"name": {
"firstName": "john",
"givenName": "maverick",
"DisplayName": "John Maverick"
},
"phone": {
"type": "mobile",
"value": "123-123-123"
}
]
Any idea how to achieve this?

Here is a Java library that may help you. http://www.jonathanhfisher.co.uk/playpen/csv2json/index.htm
Here is a JavaScript library that may or may not be useful to you. http://www.cparker15.com/code/utilities/csv-to-json/
And finally, here is a past answer that may be useful. I like the OpenCSV solution. However, instead of JAXB, you could use Jackson. Converting an CSV file to a JSON object in Java