What is the java library to remove/modify a json object based on json path, or how to fix the below issue in JsonPath?

Question

I am trying to implement a function to be able to remove or modify a json object base on a specified json path. For example, if i have a below json string/object:

{
  "PersonalDetailsDTO": {
    "FirstName": "Mark",
    "LastName": "Sully",
    "TotalDependent": "2",
    "DOB": "19811212",
    "SecQuestion": "Some Que",
    "SecAnswer": "Some-Ans",
    "Mobile": "0123456789",
    "Email": "[email protected]",
    "Title": "Mr",
    "EmploymentListDTO": [
      {
        "Type": "Full-time",
        "Probation": true
      }
    ],
    "AddressListDTO": [
      {
        "AddressType": "BUS",
        "PostCode": "1234",
        "State": "NSW",
        "StreetName": "miller",
        "StreetNumber": "111",
        "StreetType": "Invalid",
        "Suburb": "Sydney",
        "UnitNumber": "Maximum"
      }
    ]
  }
}

And i want to remove element $.PersonalDetailsDTO.AddressListDTO.PostCode.

I've done quite some search, and the one lib i found is JsonPath: http://static.javadoc.io/com.jayway.jsonpath/json-path/2.2.0/com/jayway/jsonpath/JsonPath.html

So i wrote the below code:

public static void main(String[] args) {
    // Prints "Hello, World" to the terminal window.
    String jsonString = "{\n" +
            "  \"PersonalDetailsDTO\": {\n" +
            "      \"FirstName\":\"Mark\",\n" +
            "      \"LastName\":\"Sully\",\n" +
            "      \"Title\":\"Mr\",\n" +
            "      \"DOB\":\"19811201\",\n" +
            "    \"SecQuestion\":\"Some Ques\",\n" +
            "    \"SecAnswer\":\"Some-Ans\",\n" +
            "    \"Email\":\"[email protected]\",\n" +
            "    \"EmploymentListDTO\": [\n" +
            "      {\n" +
            "        \"Type\": \"Full-time\",\n" +
            "        \"Probation\": true\n" +
            "      }\n" +
            "    ],\n" +
            "    \"AddressListDTO\": [\n" +
            "      {\n" +
            "        \"AddressType\": \"Residential\",\n" +
            "        \"PostCode\": \"2345\",\n" +
            "        \"State\": \"NSW\",\n" +
            "        \"StreetName\": \"MEL\",\n" +
            "        \"StreetNumber\": \"2\",\n" +
            "        \"StreetType\": \"Boulevard\",\n" +
            "        \"Suburb\": \"Melbourne\",\n" +
            "        \"UnitNumber\": \"345\"\n" +
            "      }\n" +
            "     ]\n" +
            "   }  \n" +
            "}";

    JSONObject jsonObject = new JSONObject(jsonString);
    System.out.println("Before: " + jsonObject.toString());

    JsonPath jp = JsonPath.compile("$.PersonalDetailsDTO.AddressListDTO[0].PostCode");
    Configuration conf = Configuration.defaultConfiguration();
    Object json = conf.jsonProvider().parse(jsonString);
    System.out.println("After: " + jp.delete(json, conf).toString());
}

And the console log displays:

Before: {"PersonalDetailsDTO":{"EmploymentListDTO":[{"Type":"Full-time","Probation":true}],"SecAnswer":"Some-Ans","Email":"[email protected]","SecQuestion":"Some Ques","FirstName":"Mark","DOB":"19811201","AddressListDTO":[{"StreetName":"MEL","Suburb":"Melbourne","State":"NSW","StreetNumber":"2","UnitNumber":"345","AddressType":"Residential","PostCode":"2345","StreetType":"Boulevard"}],"Title":"Mr","LastName":"Sully"}}


After: {PersonalDetailsDTO={FirstName=Mark, LastName=Sully, Title=Mr, DOB=19811201, SecQuestion=Some Ques, SecAnswer=Some-Ans, [email protected], EmploymentListDTO=[{"Type":"Full-time","Probation":true}], AddressListDTO=[{"AddressType":"Residential","State":"NSW","StreetName":"MEL","StreetNumber":"2","StreetType":"Boulevard","Suburb":"Melbourne","UnitNumber":"345"}]}}

Looks like JsonPath is doing it's job and removing $.PersonalDetailsDTO.AddressListDTO.PostCode. However, there's something very obvious that bothers me:

Looking at the json string produced by .toString() in before and after case, JSONObject API printed a nice string in true json standard format with every double quotes "" present, while the JsonPath .toString produce a customer string format that has some elements in double quote "" while others are not and i can not use it further like JSONObject.

And what i noticed is that although JsonPath claim to accept "java.lang.Object" as parameter in many of its function, what it truely accept is something called "jsonProvider". Not sure if it's causing the weird .toString() behavior.

Anyway, does anyone know how get a nice formatted json string out of JsonPath APIs like remove(), put(), read() and many other? Or to convert the return value to something like JSONObject?

If you know any other Java lib that can do remove/modify element by json path, please feel free to recommand. Thank you!

Questions asking us to recommend a software library are off-topic for Stack Overflow as they tend to attract opinionated answers and spam — Michael

Maksym Rudenko Maksym Rudenko · Accepted Answer · 2018-11-13T10:06:07

I don't know JsonPath.

I think you should use jackson which is defacto standard lib when work with JSON in java

aproximate what you are going to do is:

String jsonString = "{"k1": {"k2":"v2"}";

    ObjectMapper mapper = new ObjectMapper();
    JsonNode actualObj = mapper.readTree(jsonString);
    actualObj.at("/k1/k2").getValueAsInt()

and replace getValueAsInt with any other function

What is the java library to remove/modify a json object based on json path, or how to fix the below issue in JsonPath?

1 Answers