no String-argument constructor/factory method to deserialize from String value with spring boot client - spring-boot

Question

I am using spring boot application with frontend (spring boot application using thymeleaf) and backend (spring boot REST application ) are separated using REST api. The frontend uses HttpClient to send request to backend. Whenever I try to update an object the HttpClient creates an error for json parsing. The request is not accepted by the backend (ProcessDTORequest object ) with error as follows.
The exception is as follows:
{"message":"JSON parse error: Cannot construct instance of `com.app.dataaccess.entity.Process` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('68d22e4d-7116-4130-aa06-9ba120aadc66'); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.app.dataaccess.entity.Process` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('68d22e4d-7116-4130-aa06-9ba120aadc66')\n at [Source: (PushbackInputStream); line: 1, column: 10310] (through reference chain: com.app.ui.dto.request.ProcessDTORequest[\"answeredQuestionnaires\"]->java.util.HashSet[0]->com.app.dataaccess.entity.AnsweredQuestionnaire[\"process\"])","httpStatus":"INTERNAL_SERVER_ERROR","timeStamp":"2022-11-04T08:44:35.9108286Z"}
HttpClient method for post request is as follows:
public String executePost(
final String url, final Object payLoad, final Map<String, String> headers,
final Map<String, String> params) throws Exception {
final CloseableHttpClient httpClient = HttpClientBuilder.create().build();
// Add query strings to URL
URIBuilder builder = new URIBuilder(url);
for (final Map.Entry<String, String> elm : params.entrySet()) {
builder = builder.setParameter(elm.getKey(), elm.getValue());
}
// can change for HttpPut, HttpPost, HttpPatch
final HttpPost request = new HttpPost(builder.build());
// Add headers from input map
for (final Map.Entry<String, String> elm : headers.entrySet()) {
request.addHeader(elm.getKey(), elm.getValue());
}
request.setHeader("Accept", "application/json");
request.setHeader("Content-type", "application/json");
// Send Json String as body, can also send UrlEncodedFormEntity
final StringEntity entity = new StringEntity(objectMapper.writeValueAsString(payLoad));
request.setEntity(entity);
try {
final CloseableHttpResponse response = httpClient.execute(request);
System.out.println("Return response status code: "+response.getStatusLine().getStatusCode());
System.out.println("Return response status code: "+response.getStatusLine());
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
// Read response string using EntityUtils class of Apache http client library
// Serialize json string into map or any other object
return EntityUtils.toString(response.getEntity());
} else {
throw new Exception(EntityUtils.toString(response.getEntity()));
// throw new Exception(String.format("Response status code was and response was ",
// response.getStatusLine().getStatusCode(), EntityUtils.toString(response.getEntity())));
}
} catch (final ClientProtocolException e) {
throw new Exception("Client protocol Exception occurred while executing request", e);
} catch (final Exception e) {
System.out.println(e);
throw new Exception(e);
}
}
I used the configuration for object mapper as follows:
#Configuration
public class AppConfig {
#Bean
public ObjectMapper objectMapper() {
ObjectMapper objectMapper = new ObjectMapper()
.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
.configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true);
objectMapper.registerModule(new JavaTimeModule());
return objectMapper; }
}
Process.java (this is used for serializing/deserializing)
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#JsonIdentityInfo(generator = ObjectIdGenerators.UUIDGenerator.class)
public class Process {
private UUID processId;
private List<User> users = new ArrayList<>();
private List<UnitType> units = new ArrayList<>();
private String furtherComment;
private List<AnsweredQuestionnaire> answeredQuestionnaires = new ArrayList<>()
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof Process)) return false;
Process process = (Process) o;
return getProcessId().equals(process.getProcessId());
}
#Override
public int hashCode() {
return Objects.hash(getProcessId());
}
}
The json from the server is like the following
{
"#id": "bba35e58-5d4b-44ce-9a5a-486f55f79af7",
"processId": "21ef7f9d-4fcc-417c-96e8-4327206d2592",
"users": [
{
"#id": "69d2f392-8213-4f34-9cb5-f0c403170787",
"userId": "5a17ec5f-c20a-4873-93af-bf69fad4eb26",
"roles": [
{
"roleId": "f6ad33a7-9d03-4260-81c2-a4a4c791e30a",
"users": []
}
],
"processes": []
}
],
"units": [
{
"unitTypeId": "c784d197-1dc7-446e-b3e5-6468a7954878",
"unit": {
"unitId": "aba76d05-e2ea-4b5a-828b-349966595258"
},
"isResponsibleUnit": true
}
],
"furtherComment": "",
"answeredQuestionnaires": [
{
"#id": "7ca1af09-eefd-4c56-9587-581858fbbc57"
}
]
}
The relation between the entities Process, AnsweredQuestionnaire and User is as follows:
Between Process and AnsweredQuestionnaire (One-to-many) respectively.
Between Process and User (many-to-many).
Between Process and UnitType (one-to-many) respectively.
AnsweredQuestionnaire.java
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
public class AnsweredQuestionnaire {
private UUID answeredQuestionnaireId;
private Questionnaire questionnaire;
private Process process;
public void addProcessToAnsweredQuestionnaire(Process process){
//remove old association
if(this.process != null){
this.process.getAnsweredQuestionnaires().remove(this);
}
this.process = process;
//add new association
if(process != null){
this.process.getAnsweredQuestionnaires().add(this);
}
}
}
User.java
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
public class User {
private UUID userId;
private String firstName;
private String lastName;
private String phoneNumber;
private String email;
private List<Role> roles = new ArrayList<>();
private List<Process> processes = new ArrayList<>();
public void addProcessToUser(Process process){
this.processes.add(process);
process.getUsers().add(this);
}
public void removeProcessFromUser(Process process){
this.processes.remove(process);
process.getUsers().remove(this);
}
}
ProcessDTORequest.java (this class is on the backend accepting the request from the frontend)
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
public class ProcessDTORequest {
private UUID processId;
private Set<User> users = new HashSet<>();
private Set<AnsweredQuestionnaire> answeredQuestionnaires = new HashSet<>();
private Set<UnitType> units = new HashSet<>();
}
UnitType.java
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
public class UnitType {
private UUID unitTypeId;
private Unit unit;
private Boolean isResponsibleUnit = false;
}