I am trying to show DB data to my webpage.
I have made following code when GET request to the #RequestMapping(value = "/api/binder").
but when get request came to this method it will fetch data (I have print on console and display well) but it doesn't map to my Java Script Ajax call, it's showing me an error.
Following is my code for to fetch data :
#Autowired
IBinderViewRepository repository;
#RequestMapping(method= RequestMethod.GET)
public #ResponseBody
List<BinderResponse> getBinders(){
List<BinderView> binders = repository.getBinders();
List<BinderResponse> responses = new ArrayList<>();
ModelMapper mapper = Mapper.getInstance();
for(int i = 0; i < binders.size(); i++){
System.out.println("In Loop");
BinderResponse response = mapper.map(binders.get(i),BinderResponse.class);
System.out.println("Data :: " + response.getBinderName());
responses.add(response);
}
return responses;
}
but it shows me following error :
HTTP Status 500 - Could not write JSON: (was java.lang.NullPointerException) (through reference chain: java.util.ArrayList[0]->com.ngl.dto.outgoing.BinderResponse["valid"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: java.util.ArrayList[0]->com.ngl.dto.outgoing.BinderResponse["valid"])
Here is ajax call from knockout js :
ajax.get('api/binder').done(function(response){ ... }
Here BinderView and BinderResponse have same fields :
private String binderName;
private String binderAddress1;
and getter setter as well in both.
and repository.genBinders() method bring data from DB.
Here is insert method and works fine for me :
#RequestMapping(method= RequestMethod.POST,consumes = "application/json")
public #ResponseBody
IWebApiResponse addBinder(#RequestBody AddBinderForm binder){
.....
}
Shall I have to put any json annotation on my BinderResponse class ?
I don't understand where am i wrong ?Anyone pleas guide me.
UPDATE :
public class BinderResponse extends WebApiResponseBase {
private String binderName;
private String binderAddress1;
public String getBinderName() {
return binderName;
}
public void setBinderName(String binderName) {
this.binderName = binderName;
}
public String getBinderAddress1() {
return binderAddress1;
}
public void setBinderAddress1(String binderAddress1) {
this.binderAddress1 = binderAddress1;
}
}
BinderView :
public class BinderView extends BaseView {
private String binderName;
private String binderAddress1;
public String getBinderName() {
return binderName;
}
public void setBinderName(String binderName) {
this.binderName = binderName;
}
public String getBinderAddress1() {
return binderAddress1;
}
public void setBinderAddress1(String binderAddress1) {
this.binderAddress1 = binderAddress1;
}
}
In console it prints data / BinderName :
In Loop
Data :: ada
In Loop
Data :: tya
New Update :
Here is BaseView :
#MappedSuperclass
public abstract class BaseView implements IEntity {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue
#Column(name="id")
private long id;
public long getId() {
return id;
}
public void setId(long id) {
if (this.id != 0 && this.id != id) {
throw new IllegalStateException(
"The ID must not be changed after it is set.");
}
this.id = id;
}
}
and In IEntity :
public interface IEntity extends Serializable {
long getId();
void setId(long id);
}
WebApiResponseBase :
public class WebApiResponseBase implements IWebApiResponse {
private String _uri;
#Override
public String getUri() {
return _uri == null ? "" : _uri;
}
#Override
public void setUri(String uri) {
_uri = uri;
}
}
Jackson, by default, serializes an object's whole inheritance hierarchy, ie. the parent class fields as well. In the case of
public class BinderResponse extends WebApiResponseBase {
it seems like
Could not write JSON: (was java.lang.NullPointerException) (through reference chain: java.util.ArrayList[0]->com.ngl.dto.outgoing.BinderResponse["valid"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: java.util.ArrayList[0]->com.ngl.dto.outgoing.BinderResponse["valid"])
Jackson tries to serialize a field called valid from a getter called isValid (which is a conventional bean property name). The getter method, however, seems to throw a NullPointerException for whatever reason.
If you want Jackson to ignore it, you can annotate the getter with #JsonIgnore or your class with #JsonIgnoreProperties and specify the property name, ie. valid.
In my case when I used #JsonIgnore the exception has been gone but the problem was it couldn't receive that value from API Request anymore and Spring ignored it (obviously because of #JsonIgnore) So I investigated about the issue and figured out that the problem was the getter and setter.
I had the Integer property while my getter was int. So when I changed the getter to Integer my problem solved and error's gone.
private Integer purchaseId;
#JsonIgnore
public int getPurchaseId() {
return purchaseId;
}
public void setPurchaseId(int purchaseId) {
this.purchaseId = purchaseId;
}
Changed to :
private Integer purchaseId;
public Integer getPurchaseId() {
return purchaseId;
}
public void setPurchaseId(Integer purchaseId) {
this.purchaseId = purchaseId;
}
#Column(name="createddate")
private Date createdDate;
#Transient
private String formatedCreatedDate;
public String getFormatedCreatedDate() {
DateFormat dateFormat = new SimpleDateFormat("dd/mm/yyyy");
return dateFormat.format(this.getCreatedDate());
}
It throws the same exception because here may be null by calling getCreatedDate() value come so it can't format null date so keep null check here like:
Solution
public String getFormatedCreatedDate() {
DateFormat dateFormat = new SimpleDateFormat("dd/mm/yyyy");
Date createDdate=this.getCreatedDate();
if(createDdate!=null){
return dateFormat.format(createDdate);
}
return "-";
}
Related
I am writing a PUT request API with spring and mongodb. But the save() inserts a new object instead of update the current one.
#Document("Test")
public class Expense {
#Field(name = "name")
private String expenseName;
#Field(name = "category")
private ExpenseCategory expenseCategory;
#Field(name = "amount")
private BigDecimal expenseAmount;
public Expense( String expenseName, ExpenseCategory expenseCategory, BigDecimal expenseAmount) {
this.expenseName = expenseName;
this.expenseCategory = expenseCategory;
this.expenseAmount = expenseAmount;
}
public String getExpenseName() {
return expenseName;
}
public void setExpenseName(String expenseName) {
this.expenseName = expenseName;
}
public ExpenseCategory getExpenseCategory() {
return expenseCategory;
}
public void setExpenseCategory(ExpenseCategory expenseCategory) {
this.expenseCategory = expenseCategory;
}
public BigDecimal getExpenseAmount() {
return expenseAmount;
}
public void setExpenseAmount(BigDecimal expenseAmount) {
this.expenseAmount = expenseAmount;
}
}
This is my reporsitory class
public interface ExpenseRepository extends MongoRepository<Expense, String> {
}
This is my Service class which shows how to update the class.
#Service
public class ExpenseService {
private final ExpenseRepository expenseRepository;
public ExpenseService(ExpenseRepository expenseRepository) {
this.expenseRepository = expenseRepository;
}
public void updateExpense(String id, Expense expense){
Expense savedExpense = expenseRepository.findById(id)
.orElseThrow(() -> new RuntimeException(
String.format("Cannot Find Expense by ID %s", id)));
savedExpense.setExpenseName(expense.getExpenseName());
savedExpense.setExpenseAmount(expense.getExpenseAmount());
savedExpense.setExpenseCategory(expense.getExpenseCategory());
expenseRepository.save(savedExpense);
}
}
This is my controller
#RestController
#RequestMapping("/api/expense")
public class ExpenseController {
private final ExpenseService expenseService;
public ExpenseController(ExpenseService expenseService) {
this.expenseService = expenseService;
}
#PutMapping("/{id}")
public ResponseEntity<Object> updateExpense(#PathVariable String id, #RequestBody Expense expense){
expenseService.updateExpense(id, expense);
return ResponseEntity.ok().build();
}
}
As shown in mongodb compass, mongodb auto generates an _id field for every object. So I do not define a id field or use #id annotation to define a primary for the collection. However, in the service class, expenseRepository.findById(id) retrieves the desired object and update it. Why does save() do the insert instead of update? Many thanks.
JPA Can't find the existing entry as no id field id set. You need to add an id field and set generation type to auto.
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private int id;
I have a requirement where I need a subclass as object while creating a json payload.
EventBase
public class EventBase {
#JsonProperty("event_id")
private String id;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
}
PaymentCapture (the sub class)
#JsonTypeName("resource")
public class PaymentCapture extends EventBase {
#JsonProperty("parent_payment")
private String parentPayment;
public String getParentPayment() {
return parentPayment;
}
public void setParentPayment(String parentPayment) {
this.parentPayment = parentPayment;
}
}
And I need a json payload in below form:
{
"id": "someId",
"resource": {
"parent_payment": "23434"
}
}
I can understand this violates inheritance relationship, but just want to know if there is any solution available or not.
The closest I could get when having similar problem was creating an adapter class. This solution prints one extra property which might be possible to be ignored if for example some inheritance was allowed but I assume that not and use just the declared classes in addition to the adapter, which is like:
#RequiredArgsConstructor
public class PaymentCaptureAdapterClass {
#NonNull
#JsonProperty
private PaymentCapture resource;
#JsonProperty
private String getId() {
return resource.getId();
}
}
using this with code:
ObjectMapper om = new ObjectMapper();
om.enable(SerializationFeature.INDENT_OUTPUT);
PaymentCapture pc = new PaymentCapture();
pc.setId("someId");
pc.setParentPayment("23434");
log.info("\n{}", om.writeValueAsString(new AdapterClass(pc)));
prints something like:
{
"resource" : {
"event_id" : "someId", // might be able to be ignored
"parent_payment" : "23434"
},
"id" : "someId"
}
I have a Java class which has 2 List Object inside it and i am Json serializing the parent class.
#JsonSerialize
public class RequestSalesJson {
#JsonProperty("nonUniqueSalesList")
private List<SalesDataJson> getNonUniqueSalesDataJson;
#JsonProperty("uniqueSalesList")
private List<SalesDataJson> uniqueSalesDataJson;
public List<SalesDataJson> getGetNonUniqueSalesDataJson() {
return getNonUniqueSalesDataJson;
}
public void setGetNonUniqueSalesDataJson(List<SalesDataJson> getNonUniqueSalesDataJson) {
this.getNonUniqueSalesDataJson = getNonUniqueSalesDataJson;
}
public List<SalesDataJson> getUniqueSalesDataJson() {
return uniqueSalesDataJson;
}
public void setUniqueSalesDataJson(List<SalesDataJson> uniqueSalesDataJson) {
this.uniqueSalesDataJson = uniqueSalesDataJson;
}
}
SalesReturnJson.java
#JsonSerialize
public class SalesReturnJson {
#JsonProperty("starttime")
private String startTime;
#JsonProperty("pn")
private String partNumber;
#JsonProperty("so")
private String SalesOrderNumber;
#JsonProperty("wo")
private String workOrderNumber;
#JsonProperty("loc")
//other variables declared..
}
Controller.java :-
#RequestMapping(value = "/addAllSalesData",method = RequestMethod.POST)
public void addAllSalesData(#RequestBody RequestSalesJson requestSalesJsons){
log.info("POST : '/addSalesData'");
try{
System.out.print("In Controller "+requestSalesJsons.getUniqueSalesDataJson());
//salesService.processSalesData(requestSalesJsons);
}
catch(Exception e){
// return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(e.getMessage());
}
}
The value here is coming to be null.
Below is the json i am using :-
{ "uniqueSalesJson": [{"SO":4000955,"Part Number":"000","Locator":255638,"Lot Number":"P01-2059139","Reservation Quantity":2,"Status":"Released to warehouse","COE":"Fabrication","ORG":"P07","Start_Time":"2017-09-19 11:21:36"},{"SO":4000955,"Part Number":"000","Locator":255652,"Lot Number":"P01-2059140","Reservation Quantity":10,"Status":"Released to warehouse","COE":"Fabrication","ORG":"P07","Start_Time":"2017-09-19 11:21:36"}],"nonUniqueSalesJson":[{"SO":4000992,"Part Number":"1276M84G15","Locator":12345,"Lot Number":"P01-2344141","Reservation Quantity":6,"Status":"PACKED","COE":"Fabrication","ORG":"P07","Start_Time":"2017-09-19 11:21:36"},{"SO":4000992,"Part Number":"1276M84G15","Locator":12345,"Lot Number":"P01-2344141","Reservation Quantity":6,"Status":"PICKED","COE":"Fabrication","ORG":"P07","Start_Time":"2017-09-19 11:21:36"}]}
There are some issues in your code that let me doubt that your application compiles. First of all, rename the SalesReturnJson class to SalesDataJson.
Then check your #JsonProperty annotations. The value here must match exactly the property key in the Json String. Refactoring all this stuff will lead you to your root entity class:
#JsonSerialize
public class RequestSalesJson {
#JsonProperty("nonUniqueSalesJson")
private List<SalesDataJson> nonUniqueSalesDataJson;
#JsonProperty("uniqueSalesJson")
private List<SalesDataJson> uniqueSalesDataJson;
...
}
and your SalesDataJson class (missing a lot of attributes which the mapper ignores by configuration):
#JsonSerialize
public class SalesDataJson {
#JsonProperty("Start_Time")
private String startTime;
#JsonProperty("Part Number")
private String partNumber;
#JsonProperty("SO")
private String SalesOrderNumber;
}
This sample works as expected with the com.fasterxml.jackson.databind.ObjectMapper
Hope that helps!
I have made restful API Using java hibernate jersery Framework.
I have to post data I have done it but I'm missing with one of the column that is MealTypeName.
Here is my DAO Class:
public class MealTypeDAO {
public void addMealType( MealType bean) {
Session session = SessionUtil.getSession();
Transaction tx = session.beginTransaction();
addMealType(session, bean);
tx.commit();
session.close();
}
private void addMealType(Session session, MealType bean){
MealType mealType = new MealType();
mealType.setMealTypename(bean.getMealTypename());
mealType.setModifiedon(bean.getModifiedon());
mealType.setModifiedby(bean.getModifiedby());
session.save(mealType);
}
Here is my resource class:
public class MealTypeResource {
#POST
#Path("/create")
#Consumes("application/json")
public Response addMealType(MealType meal){
meal.setMealTypename(meal.getMealTypename());
meal.setModifiedon(meal.getModifiedon());
meal.setModifiedby(meal.getModifiedby());
MealTypeDAO dao = new MealTypeDAO();
dao.addMealType(meal);
return Response.ok().build();
}
#GET
#Produces("application/json")
public Response getMealType() {
MealTypeDAO dao = new MealTypeDAO();
List mealTypes = dao.getMealType();
String json = new Gson().toJson(mealTypes);
return Response.ok().entity(json.toString()).build();
}
This is my entity class:
public class MealType {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private int MealTypeId;
#Column
private String MealTypename;
#Column
private int modifiedby;
#Column
private String modifiedon;
public int getMealTypeId() {
return MealTypeId;
}
public void setMealTypeId(int mealTypeId) {
MealTypeId = mealTypeId;
}
public String getMealTypename() {
return MealTypename;
}
public void setMealTypename(String mealTypename) {
MealTypename = mealTypename;
}
public int getModifiedby() {
return modifiedby;
}
public void setModifiedby(int modifiedby) {
this.modifiedby = modifiedby;
}
public String getModifiedon() {
return modifiedon;
}
public void setModifiedon(String modifiedon) {
this.modifiedon = modifiedon;
}
MySQL DB:
CREATE TABLE `mealtype`(`Mealtypeid` int(11) NOT NULL AUTO_INCREMENT,`MealTypename` varchar(20) DEFAULT NULL,`modifiedby` int(11) NOT NULL,`modifiedon` datetime NOT NULL,PRIMARY KEY (`Mealtypeid`)) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;
Now M posting these data in JSON FORMAT From POSTMAN:
{"MealTypeId":14,"MealTypename":"adsdf","modifiedby":1,"modifiedon":"2000-01-01 00:00:00"}
And M getting these data:
{"MealTypeId":14,"modifiedby":1,"modifiedon":"2000-01-01 00:00:00"}
MealTypename is missing. How so? Can someone help me out?
You are using names with the first letter in the upper case MealTypename — this is a reason.
The getter with name getMealTypename is used for a JSON property mealTypename (not MealTypename):
public String getMealTypename() {
return MealTypename;
}
You need to specify a JSON property name:
#JsonProperty("MealTypename") — for Jackson
#SerializedName("MealTypename") — for Gson
You need to put this annotation to the field or getter of the class which you mapping to JSON (MealType).
And use the standard Java naming convention.
public class MealType {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private int mealTypeId;
#Column
private String mealTypename;
}
And this looks really strange:
meal.setMealTypename(meal.getMealTypename());
meal.setModifiedon(meal.getModifiedon());
meal.setModifiedby(meal.getModifiedby());
I use jackson 2 to convert json into a java object. So far so good. But I also use hazelcast to distribute the objects in a cluster. Therefore all beans have to be java.io.Serializable. When I read the Object from json like so:
ObjectMapper mapper = new ObjectMapper();
mapper.addMixInAnnotations(AbstractBean.class, MongoIdMixIn.class);
// this is to prevent from failing on missing type class property: #JsonProperty("#class")
Object tgtObject = targetClass.newInstance();
mapper.readerForUpdating(tgtObject).readValue(dbo.toString());
// put into hazelcast map
target.put(dbo.get(keyColumn), tgtObject);
I will get an exception from hazelcast:
java.io.NotSerializableException: com.fasterxml.jackson.databind.deser.impl.TypeWrappedDeserializer
I am wondering where the com.fasterxml.jackson.databind.deser.impl.TypeWrappedDeserializer is coming from since the Object is a plain java bean (but using inheritance).
My Abstract class is:
#JsonSerialize(include=JsonSerialize.Inclusion.NON_NULL)
#JsonIgnoreProperties(ignoreUnknown = true)
#JsonTypeInfo(use=JsonTypeInfo.Id.CLASS, include=JsonTypeInfo.As.PROPERTY, property="#javaClass")
public abstract class AbstractBean implements Serializable {
#JsonIgnore public static final transient IMarkupParser MARKUP_PARSER = new WikiMarkupParser();
#JsonProperty("id")
private String id;
#JsonProperty("#class")
private String clazz;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getClazz() {
return this.getClass().getSimpleName();
}
}
And my child is:
public class Posting extends AbstractBean {
private String postingSource;
private String languageCode;
public String getPostingSource() {
return postingSource;
}
public void setPostingSource(String postingSource) {
this.postingSource = postingSource;
}
public String getLanguageCode() {
return languageCode;
}
public void setLanguageCode(String languageCode) {
this.languageCode = languageCode;
}
}
I have no Idea why the serailizer would even try to serialize the mixins since the are not part of the bean but here they are (yes I have tried to make them serializable too, just as a test, no luck):
public interface IdMixins extends Serializable {
}
public interface MongoIdMixIn extends IdMixins {
#JsonProperty("_id")
#JsonSerialize(using = MongoIdSerializer.class)
public String getId();
#JsonProperty("_id")
#JsonDeserialize(using = MongoIdDeserializer.class)
public void setId(String id);
}
public class MongoIdDeserializer extends JsonDeserializer<String> implements Serializable {
private static final long serialVersionUID = -5404276857799190647L;
#Override
public String deserialize(JsonParser jp, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
String value = null;
String tmp = jp.getText(); // {
validate(jp, tmp,"{");
int curly = 1;
while (jp.nextToken() != null) {
String v = jp.getText();
if (v.equals("{")) curly++;
if (v.equals("$oid")) {
jp.nextToken();
value = jp.getText();
}
if (v.equals("}")) curly--;
if (curly<=0) return value;
}
return null;
}
private void validate(JsonParser jsonParser, String input, String expected) throws JsonProcessingException {
if (!input.equals(expected)) {
throw new JsonParseException("Unexpected token: " + input, jsonParser.getTokenLocation());
}
}
}
public class MongoIdSerializer extends JsonSerializer<String> implements Serializable {
private static final long serialVersionUID = 3435689991839324194L;
#Override
public void serialize(String s, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
jsonGenerator.writeStartObject();
jsonGenerator.writeFieldName("$oid");
jsonGenerator.writeString(s);
jsonGenerator.writeEndObject();
}
}
Stupid me! Somewhere in the serialization chain was a completely unnecessary ObjectMapper object. But it was hard to find because not the Posting object was the real reason, instead it was another object. But the Stacktrace and the com.fasterxml.jackson.databind.deser.impl.TypeWrappedDeserializer Exception were completely miss leading! ... clustered software is sometimes really painful to debug :-)
I'm 1 Rep. Point away from being able to comment. So I have to make a suggestion as an answer ;-).
Perhaps one of the Annotations do inject an instance of TypeWrappedDeserializer as a private property into the AbstractBean. Maybe as hint for the deserialization mechanism.
Could you inspect the created object with reflection to verify?
for (Field field : tgtObject.getClass().getDeclaredFields() )
{
// you can replace this by your logging method
System.out.println("Field: " + field.getName() + ":" + field.getType());
}
for (Field field : tgtObject.getClass().getSuperclass().getDeclaredFields() )
{
// you can replace this by your logging method
System.out.println("Field: " + field.getName() + ":" + field.getType());
}
If you find the apropriate type in the listing the Class was added by Byte Code Enhancement.