We Keep Coding

RequestBody handling a JSON containing Strings and a List

I'm sending a post request from the client to the server. The body of the post request looks like this:
...
body: JSON.stringify
({
command: 'someString',
dataFields: setDataList()
})
...
while the "setDataList()" returns the following structure:
[ {…}, {…}, {…}, ..., {…} ]
[0: {type: "_header_", label: "upload"}
1: {type: "_image_", name: "data:image/jpeg;base64", value: "base64 encoded string", label: "someImage.JPG"}
2: {...}]
I'm having issues processing the content of the "dataFields" key at the server. Currently, the SpringBoot applicaiton looks like this:
#PostMapping(
consumes = {MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_XML_VALUE},
produces = {MediaType.APPLICATION_JSON_VALUE})
public void postBody(#RequestBody ManageRequest manageRequest) {
...
}
and "ManageRequest" like this:
import java.util.List;
public class ManageRequest {
private String accountId;
private String command;
private String transactionId;
private List<String> dataFields;
public String getAccountId() {
return accountId;
}
public String getTransactionId() {
return transactionId;
}
public void setTransactionId(String transactionId) {
this.transactionId = transactionId;
}
public void setAccountId(String accountId) {
this.accountId = accountId;
}
public String getCommand() {
return command;
}
public void setCommand(String command) {
this.command = command;
}
public List<String> getDataFieldList() {
return dataFields;
}
public void setDataFieldList(List<String> dataList) {
this.dataFields = dataList;
}
}
I'm not experienced in handling such requests with Java. My goal would be to extract the content of the "dataFields" like this: "dataFields[0], dataFields[1], ..." and allocate them to a new List to add to a post request.
At the moment, the list seems to be empty when arriving at the end point.

Your problems is with the List.
The server is waiting for a List of Strings but you are sending a List of objects with fields that are Strings.
private List<String> dataFields; // This property is a List of string not a list of "dataFields"
You should create a class DataField and it would looks like this
public class DataField{
private String type;
private String label;
private String name;
.
.
.
}
And then in your ManageRequest class you should do like this:
public class ManageRequest {
private String accountId;
private String command;
private String transactionId;
private List<DataField> dataFields;
//Getter and setters
}

reading the value of an array of json and putting it into set through java

I am using Jackson library with java 11 so basically I am able to read the below JSON into a string format
{
"schemas":[
"urn:params:core:2.0:User",
"urn:params:core:3.0:User"
],
},
}
here below is the set in which I have to fill the values of schemas from above json
private Set<String> setschemas = null;
right now I am able to read the above json into a string named finaljson , now please advise how can I read the differnt value of schemas from above json string named finaljson and set it to set named setschemas
if (node.has("schemas")) {
// *** here I want to read the differernt value of schemas and set it to a set
// named setschemas
// *****
}

you can create the following classes that represent the json structure
class MyJsonObject {
private AppIdentity appIdentity;
private Set<String> schemas;
private String userName;
}
class AppIdentity {
private String clientId;
private String username;
}
than you can use
final MyJsonObject myJsonObject = new ObjectMapper().readValue(finaljson, MyJsonObject.class); to read the json to JAVA object
so it can manipulated like myJsonObject.schemas.size() > 0 and such...
there are a lot of examples in the internet
*keep in mind, this solution only works when the json structure and fields name are known in advanced

With your approach, this would be simplest one:
if(node.has("schemas")) {
JsonNode schemaNode = node.get("schemas");
Set<String> schemaSet = objectMapper.convertValue(schemaNode, Set.class);
System.out.println("schemaSet" + schemaSet);
}
There are various ways to deal with JSON one is described here
1) You can create a class of JSON structure as follows with help online JSON to POJO convertor (Note:: Add Setters and Getters with help of IDE)
class AppJson {
private Set<AppIdentity> appIdentity;
private Set<String> schemas;
private String userName;
private Manager ManagerObject;
private String division;
private String organization;
private String costCenter;
private String employeeNumber;
}
class AppIdentity {
private String clientId;
private String username;
}
class Manager {
private String value;
private String $ref;
private String displayName;
private String $Ref;
}
2) Use above for object conversion.
ObjectMapper objectMapper = new ObjectMapper();
String jsonString = "{\"appIdentity\":[{\"clientId\":\"9a41763c642\",\"username\":\"XXX\"}],\"schemas\":[\"urn:params:core:2.0:User\",\"urn:params:core:3.0:User\"],\"userName\":\"ajklmnop_699100\",\"manager\":{\"value\":\"string\",\"$ref\":\"sdkoirk\",\"displayName\":\"string\",\"$Ref\":\"sdkweoirk\"},\"division\":\"string\",\"organization\":\"string\",\"costCenter\":\"string\",\"employeeNumber\":\"string\"}\n"
+ "";
AppJson appJson = objectMapper.readValue(jsonString, AppJson.class);
System.out.println("json " + appJson.getSchemas());
Here you will get the schemas.

Java object not populated from json request for inner class

Have searched in different sites but couldn't find correct answer, hence posting this request though it could possible duplicates.sorry for that.
I am sending the below json request to my back-end service and converting to java object for processing. I can see the request body passed to my service but when i convert from json to java object , values are not populating
{
"data":{
"username":"martin",
"customerId":1234567890,
"firstName":"john",
"lastName":"smith",
"password":"p#ssrr0rd##12",
"email":"john.smith#gmail.com",
"contactNumber":"0342323443",
"department":"sports",
"location":"texas",
"status":"unlocked",
"OrderConfigs":[
{
"vpnId":"N4234554R",
"serviceId":"connectNow",
"serviceType":"WRLIP",
"ipAddress":"10.101.10.3",
"fRoute":[
"10.255.253.0/30",
" 10.255.254.0/30"
],
"timeout":1800,
"mapId":"test_map"
}
]
}
}
My Parser class have something like,
JSONObject requestJSON = new JSONObject(requestBody).getJSONObject("data");
ObjectMapper mapper = new ObjectMapper();
final String jsonData = requestJSON.toString();
OrderDTO mappedObject= mapper.readValue(jsonData , OrderDTO .class);
// I can see value coming from front-end but not populating in the mappedObject
My OrderDTO.java
#JsonInclude(value = Include.NON_NULL)
#JsonIgnoreProperties(ignoreUnknown = true,value = {"hibernateLazyInitializer", "handler", "created"})
public class OrderDTO {
private String username;
private long customerId;
private String source;
private String firstName;
private String lastName;
private String email;
private String contactNumber;
private String password;
private String department;
private String location;
private String status;
private List<OrderConfig> OrderConfigs;
#JsonInclude(value = Include.NON_NULL)
public class OrderConfig {
private String vpnId;
private String serviceId;
private String serviceType;
private String ipAddress;
private String mapId;
private String[] fRoutes;
private Map<String, Object> attributes;
private SubConfig subConfig;
private String routeFlag;
getter/setters
.....
}
all setter/getter
}
Not sure what I'm missing here. Is this right way to do?

If your are trying to use inner class, correct way to use is to declare it static for Jackson to work with inner classes.
For reference check this
code changes made are
#JsonInclude(value = Include.NON_NULL)
#JsonIgnoreProperties(ignoreUnknown = true)
static class OrderConfig {
Make sure that your json tag names match with variable names of java object
Ex : "fRoute":[
"10.255.253.0/30",
" 10.255.254.0/30"
],
private String[] fRoutes;

OrderConfigs fields will not be initialized, just modify your bean as
#JsonProperty("OrderConfigs")
private List<OrderConfig> orderConfigs;
// setter and getter as setOrderConfigs / getOrderConfigs
See my answer here. (same issue)

Json string to java object

I'm having following class
public class ReturnData {
public ReturnData() {
OperationResult = Result.Failed;
Messages = "An Error Occured";
UpdateAvailable = "0";
ResultData = "";
}
public Result OperationResult;
public String Messages;
public String UpdateAvailable;
public Object ResultData;
}
I'm having json string like,
{"OperationResult":0,"Messages":"","UpdateAvailable":"","ResultData":{"SessionId":"3b44a524-fc2a-499b-a16e-6d96339a6b5b","UserName":"admin","AccoundId":null,"Roles":["Administrator"],"DisplayName":"Admin","Status":3,"Type":1}}
I want to assign this json string to above class.I'm using GSON for assign json string to java object.In normal class i can assign json string to java object. But for this class i couldn't assign directly. Please any one help me,
Now i'm assigning like,
String formatedjsonstring = {json string};
Log.i("FORMAT STRING:",formatedjsonstring);
Gson gson = new Gson();
ReturnData returndata = (ReturnData) gson.fromJson(
formatedjsonstring, ReturnData.class);

You could use JavaJson from sourceforge. You could pass your json string to JsonObject .parse().
Try this
JsonObject json = JsonObject .parse("{\"OperationResult\":0, \"Messages\":\"UpdateAvailable\"");
System.out.println("OperationResult=" + json.get("OperationResult"));
System.out.println("Messages=" + json.get("Messages"));
https://sourceforge.net/projects/javajson/

Since your Java class doesn't resemble your JSON in any way, shape or form ... you're going to have a problem with that.
Problem #1: OperationResult should be an int
Problem #2: You're declared ResultData as an Object ... Java doesn't work like that.
You need your POJO to match the JSON:
public class ReturnData {
public ReturnData() {
OperationResult = Result.Failed;
Messages = "An Error Occured";
UpdateAvailable = "0";
ResultData = "";
}
public int OperationResult;
public String Messages;
public String UpdateAvailable;
public MyResultData ResultData;
}
class MyResultData {
public String SessionId;
public String UserName;
public String AccountId;
public List<String> Roles;
public String DisplayName;
public int Status;
public int Type;
}
ReturnData rd = new Gson().fromJson(jsonString, ReturnData.class);
I'd also consider using Gson's #SerializedName("name") annotation to convert the PascalCase field names in your JSON to camelCase field names in Java.
#SerializedName("OperationResult") public int operationResult;

Try this:
java.lang.reflect.Type type = new TypeToken<ReturnData>(){}.getType();
ReturnData rd = new Gson().fromJson(jsonString, type);

Serializing JSON string to object

I am trying to parse through a JSON string and convert it to the following POJO:
package apicall;
//POJO representation of OAuthAccessToken
public class OAuthAccessToken {
private String tokenType;
private String tokenValue;
public OAuthAccessToken(String tokenType,String tokenValue) {
this.tokenType=tokenType;
this.tokenValue=tokenValue;
}
public String toString() {
return "tokenType="+tokenType+"\ntokenValue="+tokenValue;
}
public String getTokenValue() {
return tokenValue;
}
public String getTokenType() {
return tokenType;
}
}
In order to do this I have written the following code:
Gson gson=new Gson();
String responseJSONString="{\"access_token\" : \"2YotnFZFEjr1zCsicMWpAA\",\"token_type\" : \"bearer\"}";
OAuthAccessToken token=gson.fromJson(responseJSONString, OAuthAccessToken.class);
System.out.println(token);
When I run the code, I get the following output:
tokenType=null
tokenValue=null
Instead of
tokenType=bearer
tokenValue=2YotnFZFEjr1zCsicMWpAA
I don't understand if there's anything I've done wrong. Please help.

You can get the expected result by annotating your fields like:
#SerializedName("token_type")
private final String tokenType;
#SerializedName("access_token")
private final String tokenValue;

How is Gson supposed to know how to populate your object? You don't have a no-arg constructor, and the fields of your object don't match the fields in the JSON object.
Make your object as following:
public class OAuthAccessToken {
private String accessToken;
private String tokenType;
OAuthAccessToken() {
}
...
}

The class should have the exact field name as the json, so if your json have 2 keys: "access_token" and "token_type", the class should have 2 fields:
private String access_token;
private String token_type;
And, of course you need to change the getters/setters accordingly.