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How to fix missing descriptor for class POJO after update server? [duplicate]

I'm using EclipseLink to run some Native SQL. I need to return the data into a POJO. I followed the instructions at EclipseLink Docs, but I receive the error Missing descriptor for [Class]
The query columns have been named to match the member variables of the POJO. Do I need to do some additional mapping?
POJO:
public class AnnouncementRecipientsFlattenedDTO {
private BigDecimal announcementId;
private String recipientAddress;
private String type;
public AnnouncementRecipientsFlattenedDTO() {
super();
}
public AnnouncementRecipientsFlattenedDTO(BigDecimal announcementId, String recipientAddress, String type) {
super();
this.announcementId = announcementId;
this.recipientAddress = recipientAddress;
this.type = type;
}
... Getters/Setters
Entity Manager call:
public List<AnnouncementRecipientsFlattenedDTO> getNormalizedRecipientsForAnnouncement(int announcementId) {
Query query = em.createNamedQuery(AnnouncementDeliveryLog.FIND_NORMALIZED_RECIPIENTS_FOR_ANNOUNCEMENT, AnnouncementRecipientsFlattenedDTO.class);
query.setParameter(1, announcementId);
return query.getResultList();
}

I found out you can put the results of a Native Query execution into a List of Arrays that hold Objects. Then one can iterate over the list and Array elements and build the desired Entity objects.
List<Object[]> rawResultList;
Query query =
em.createNamedQuery(AnnouncementDeliveryLog.FIND_NORMALIZED_RECIPIENTS_FOR_ANNOUNCEMENT);
rawResultList = query.getResultList();
for (Object[] resultElement : rawResultList) {
AnnouncementDeliveryLog adl = new AnnouncementDeliveryLog(getAnnouncementById(announcementId), (String)resultElement[1], (String)resultElement[2], "TO_SEND");
persistAnnouncementDeliveryLog(adl);
}

You can only use native SQL queries with a class if the class is mapped. You need to define the AnnouncementRecipientsFlattenedDTO class as an #Entity.
Otherwise just create the native query with only the SQL and get an array of the data back and construct your DTO yourself using the data.

Old question but may be following solution will help someone else.
Suppose you want to return a list of columns, data type and data length for a given table in Oracle. I have written below a native sample query for this:
private static final String TABLE_COLUMNS = "select utc.COLUMN_NAME, utc.DATA_TYPE, utc.DATA_LENGTH "
+ "from user_tab_columns utc "
+ "where utc.table_name = ? "
+ "order by utc.column_name asc";
Now the requirement is to construct a list of POJO from the result of above query.
Define TableColumn entity class as below:
#Entity
public class TableColumn implements Serializable {
#Id
#Column(name = "COLUMN_NAME")
private String columnName;
#Column(name = "DATA_TYPE")
private String dataType;
#Column(name = "DATA_LENGTH")
private int dataLength;
public String getColumnName() {
return columnName;
}
public void setColumnName(String columnName) {
this.columnName = columnName;
}
public String getDataType() {
return dataType;
}
public void setDataType(String dataType) {
this.dataType = dataType;
}
public int getDataLength() {
return dataLength;
}
public void setDataLength(int dataLength) {
this.dataLength = dataLength;
}
public TableColumn(String columnName, String dataType, int dataLength) {
this.columnName = columnName;
this.dataType = dataType;
this.dataLength = dataLength;
}
public TableColumn(String columnName) {
this.columnName = columnName;
}
public TableColumn() {
}
#Override
public int hashCode() {
int hash = 0;
hash += (columnName != null ? columnName.hashCode() : 0);
return hash;
}
#Override
public boolean equals(Object object) {
if (!(object instanceof TableColumn)) {
return false;
}
TableColumn other = (TableColumn) object;
if ((this.columnName == null && other.columnName != null) || (this.columnName != null && !this.columnName.equals(other.columnName))) {
return false;
}
return true;
}
#Override
public String toString() {
return getColumnName();
}
}
Now we are ready to construct a list of POJO. Use the sample code below to construct get your result as List of POJOs.
public List<TableColumn> findTableColumns(String table) {
List<TableColumn> listTables = new ArrayList<>();
EntityManager em = emf.createEntityManager();
Query q = em.createNativeQuery(TABLE_COLUMNS, TableColumn.class).setParameter(1, table);
listTables = q.getResultList();
em.close();
return listTables;
}

Also, don't forget to add in your POJO class in persistence.xml! It can be easy to overlook if you are used to your IDE managing that file for you.

Had the same kind of problem where I wanted to return a List of POJOs, and really just POJOs (call it DTO if you want) and not #Entity annotated Objects.
class PojoExample {
String name;
#Enumerated(EnumType.STRING)
SomeEnum type;
public PojoExample(String name, SomeEnum type) {
this.name = name;
this.type = type;
}
}
With the following Query:
String query = "SELECT b.name, a.newtype as type FROM tablea a, tableb b where a.tableb_id = b_id";
Query query = getEntityManager().createNativeQuery(query, "PojoExample");
#SuppressWarnings("unchecked")
List<PojoExample> data = query.getResultList();
Creates the PojoExample from the database without the need for an Entity annotation on PojoExample. You can find the method call in the Oracle Docs here.
edit:
As it turns out you have to use #SqlResultSetMapping for this to work, otherwise your query.getResultList() returns a List of Object.
#SqlResultSetMapping(name = "PojoExample",
classes = #ConstructorResult(columns = {
#ColumnResult(name = "name", type = String.class),
#ColumnResult(name = "type", type = String.class)
},
targetClass = PojoExample.class)
)
Just put this anywhere under your #Entity annotation (so in this example either in tablea or tableb because PojoExample has no #Entity annotation)

Cannot POST A COLUMN RESTFUL API

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());

Hibernate NamedQuery, set values

Good evening! I am trying to set values from my query to wrapper class TestWrapper
TestWrapper class:
package com.bionic.wrappers;
public class TestWrapper {
private String name;
private int duration;
public TestWrapper(){
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getDuration() {
return duration;
}
public void setDuration(int duration) {
this.duration = duration;
}
}
Here is my query:
#NamedQuery(name = "getAvailableTestsNames",
query = "SELECT test.testName, test.duration FROM Result result JOIN result.test test JOIN result.user user where user.id = :userId"
and DAO class:
public List<TestWrapper> getAvailableTestsNames(long id){
Query query = em.createNamedQuery("getAvailableTestsNames");
query.setParameter("userId", id);
return (List<TestWrapper>)query.getResultList();
}
I get an exeption and i see that values won't set appropriate here:
public static Set<TestDTO> convertAvailableTestsToDTO(List<TestWrapper> tests){
Set<TestDTO> testDTOs = new HashSet<>();
for (TestWrapper test : tests){
TestDTO testDTO = new TestDTO(test.getName(), test.getDuration());
testDTOs.add(testDTO);
}
return testDTOs;
}
I get an expeption:
java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to com.bionic.wrappers.TestWrapper
Thank you!

I don't have enough context but in the getAvailableTestsNames meth. looks like you're doing a query that returns scalar results by returning "test.testName, test.duration" where you probably just want to return a List of TestWrapper so the query should just be " from XXX" , you can omit the select field1,field2 ... hibernate does that for you.
See section 11.4.1.3. Scalar results of https://docs.jboss.org/hibernate/orm/4.3/manual/en-US/html/ch11.html#objectstate-querying vs. 11.4.1. Executing queries
Hope this helps
Aa.

How to bind empty numeric field to default value 0 in spring mvc

I have some numeric fields(but not compulsory) in my jsp form
eg. kkqty, sogoqty and sesaqty.
so when user not giving any input in those fields I m receiving Null at my controller side hence getting null property exception while saving these form data
My POJO (OutletInfo.java)
private Double kkqty;
private Double sogoqty;
private Double sesaqty;
//getter & setters
#Column(name = "KKqty", nullable = false, precision = 10)
public Double getKkqty() {
return this.kkqty;
}
public void setKkqty(Double kkqty) {
this.kkqty = kkqty;
}
#Column(name = "sogoqty", nullable = false, precision = 10)
public Double getSogoqty() {
return this.sogoqty;
}
public void setSogoqty(Double sogoqty) {
this.sogoqty = sogoqty;
}
#Column(name = "sesaqty", nullable = false, precision = 10)
public Double getSesaqty() {
return this.sesaqty;
}
My Controller
#RequestMapping(value = "saveOutletInfo", method = RequestMethod.POST)
public #ResponseBody String saveOutletInfo(OutletInfo outletInfo,HttpServletRequest request){
System.out.print("KKQTY:"+outletInfo.getKkqty());
return this.getMasterService().saveOutletInfo(outletInfo);
}
In controller when I m trying to print all numeric fields , I am receiving null here,hence not able to save .
I need to convert instead of null to default value 0.0
one way I know that i need to check all fields if null then set it to 0.0 but this is pretty much hard coded ,so i want automatic conversion in this scenario.
I gone through some post and came across about #InitBinder but i m unable to use it in such case.
somthing like
#InitBinder
public void initBinder(WebDataBinder binder) {
binder.registerCustomEditor(Double.class, new CustomNumberEditor(Double.class, true));
}
can anyone suggest how i can automatically convert to all my numeric fields to 0.0 when it is null.

You can set up a global init-binder, something like
#ControllerAdvice
public class GlobalBindingInitializer {
/* global InitBinder */
#InitBinder
public void binder(WebDataBinder binder) {
binder.registerCustomEditor(Double.class, new CustomDoubleEditor());
}
}
and register the following editor
public class CustomDoubleEditor extends PropertyEditorSupport {
public CustomDoubleEditor() {
}
public String getAsText() {
Double d = (Double) getValue();
return d.toString();
}
public void setAsText(String str) {
if (str == "" || str == null)
setValue(0);
else
setValue(Double.parseDouble(str));
}
}
however, in your context, a more appropriate solution seems to be to simply initialize the instance variables or set a default constructor to the value of 0
private Double kkqty = 0.0;
private Double sogoqty = 0.0;
private Double sesaqty = 0.0;

Json API Parsing troubles with Java

I'm running into a few issues similar to what others have had in the past with Json parsing in Java. This is the first time I try something like this so any help/tips is extremely useful.
I'm trying to parse in data from this site: https://api.bitcoinaverage.com/exchanges/USD
I have tried numerous ways with both Json and Gson. And have tried looking for help here but to no avail.
Here are the classes that are set up (these were auto generated):
Info.java:
public class Info{
private String display_URL;
private String display_name;
private Rates[] rates;
private String source;
private Number volume_btc;
private Number volume_percent;
public String getDisplay_URL(){
return this.display_URL;
}
public void setDisplay_URL(String display_URL){
this.display_URL = display_URL;
}
public String getDisplay_name(){
return this.display_name;
}
public void setDisplay_name(String display_name){
this.display_name = display_name;
}
public Rates[] getRates(){
return this.rates;
}
public void setRates(Rates[] rates){
this.rates = rates;
}
public String getSource(){
return this.source;
}
public void setSource(String source){
this.source = source;
}
public Number getVolume_btc(){
return this.volume_btc;
}
public void setVolume_btc(Number volume_btc){
this.volume_btc = volume_btc;
}
public Number getVolume_percent(){
return this.volume_percent;
}
public void setVolume_percent(Number volume_percent){
this.volume_percent = volume_percent;
}
}
Rates.java:
public class Rates {
private Number ask;
private Number bid;
private Number last;
public Number getAsk(){
return this.ask;
}
public void setAsk(Number ask){
this.ask = ask;
}
public Number getBid(){
return this.bid;
}
public void setBid(Number bid){
this.bid = bid;
}
public Number getLast(){
return this.last;
}
public void setLast(Number last){
this.last = last;
}
}
MainClass.java:
public class MainClass {
public static void main(String[] args) throws Exception {
Gson gson = new Gson();
String json = readUrl("https://api.bitcoinaverage.com/exchanges/USD");
Info page = gson.fromJson(json, Info.class);
System.out.println(page.getDisplay_name());
}
private static String readUrl(String urlString) throws Exception {
BufferedReader reader = null;
try {
URL url = new URL(urlString);
reader = new BufferedReader(new InputStreamReader(url.openStream()));
StringBuffer buffer = new StringBuffer();
int read;
char[] chars = new char[1024];
while ((read = reader.read(chars)) != -1)
buffer.append(chars, 0, read);
return buffer.toString();
} finally {
if (reader != null)
reader.close();
}
}
}
When I try to call a getter, a null is returned.
How do I go about parsing the data properly, and then being able to call an attribute from which ever object I want? For example, if I want an attribute from "anx_hk" or "bitfinex".
This is the first time me posting something here so I hope I'm following the proper guidelines.
I also plan on passing this over to Android once I get the fell for parsing Json better. Thanks for the help! It'll greatly be appreciated.

I'll be honest with you, that's a pretty lame API response. Here it is
{
"anx_hk": {
"display_URL": "https://anxbtc.com/",
"display_name": "ANXBTC",
"rates": {
"ask": 454.26,
"bid": 444.46,
"last": 443.78
},
"source": "bitcoincharts",
"volume_btc": 11.73,
"volume_percent": 0.02
},
...,
"timestamp": "Fri, 04 Apr 2014 04:30:26 -0000",
...
}
There's no JSON array here, so you can get rid of all your array types. This response is a JSON object, which contains a bunch of JSON objects (which share a format) and a JSON name value pair where the name is timestamp.
The common JSON objects have two fields of type double (that's what type your field should be, not Number)
"volume_btc": 11.73,
"volume_percent": 0.02
, three fields of type String
"display_URL": "https://anxbtc.com/",
"display_name": "ANXBTC",
"source": "bitcoincharts",
and one that is a JSON object that contains three more doubles
"rates": {
"ask": 454.26,
"bid": 444.46,
"last": 443.78
}
The actual issue here is that, I'm assuming, the JSON objects in the root JSON object have names that may change or new ones may be added. This is not a good fit for a POJO. Instead you'd want to use a Map<String, Info>, but Gson can't map to that by default. It is not well suited for such deserialization. You'd have to provide your own TypeAdapter.
Instead, I'm going to suggest you use Jackson.
If we put that all together, we get something like
class ApiResponse {
private Map<String, Info> page = new HashMap<>();
private Date timestamp;
public Map<String, Info> getPage() {
return page;
}
#JsonAnySetter
public void setPage(String name, Info value) {
page.put(name, value);
}
public Date getTimestamp() {
return timestamp;
}
public void setTimestamp(Date timestamp) {
this.timestamp = timestamp;
}
}
class Info {
private String display_URL;
private String display_name;
private Rates rates;
private String source;
private Double volume_btc;
private Double volume_percent;
public String getDisplay_URL() {
return this.display_URL;
}
public void setDisplay_URL(String display_URL) {
this.display_URL = display_URL;
}
public String getDisplay_name() {
return this.display_name;
}
public void setDisplay_name(String display_name) {
this.display_name = display_name;
}
public Rates getRates() {
return this.rates;
}
public void setRates(Rates rates) {
this.rates = rates;
}
public String getSource() {
return this.source;
}
public void setSource(String source) {
this.source = source;
}
public Double getVolume_btc() {
return this.volume_btc;
}
public void setVolume_btc(Double volume_btc) {
this.volume_btc = volume_btc;
}
public Double getVolume_percent() {
return this.volume_percent;
}
public void setVolume_percent(Double volume_percent) {
this.volume_percent = volume_percent;
}
}
class Rates {
private Double ask;
private Double bid;
private Double last;
public Number getAsk() {
return this.ask;
}
public void setAsk(Double ask) {
this.ask = ask;
}
public Double getBid() {
return this.bid;
}
public void setBid(Double bid) {
this.bid = bid;
}
public Double getLast() {
return this.last;
}
public void setLast(Double last) {
this.last = last;
}
}
With deserialization code such as
String json = readUrl("https://api.bitcoinaverage.com/exchanges/USD");
ObjectMapper mapper = new ObjectMapper();
ApiResponse response = mapper.readValue(json, ApiResponse.class);
System.out.println(response);
With appropriate toString() methods (mine were auto-generated with Eclipse), you would get something like
ApiResponse [pages={bitkonan=Info [display_URL=https://bitkonan.com/, display_name=BitKonan, rates=Rates [ask=475.0, bid=438.01, last=437.0], source=api, volume_btc=7.24, volume_percent=0.01], vaultofsatoshi=Info [display_URL=https://vaultofsatoshi.com, display_name=Vault of Satoshi, rates=Rates [ask=460.0, bid=460.0, last=460.0], source=api, volume_btc=11.46, volume_percent=0.02], bitstamp=Info [display_URL=https://bitstamp.net/, display_name=Bitstamp, rates=Rates [ask=439.16, bid=436.34, last=436.34], source=api, volume_btc=22186.29, volume_percent=35.19], ...}, timestamp=Fri Apr 04 01:02:43 EDT 2014]
as output.

The api response contains many objects, but seems that you are trying to read them as a single Info object.
You may try to read the response as a Map<String, Info>, and iterate the entries.
Map<String, Info> hashMap = gson.fromJson(body, HashMap.class);
for (Map.Entry entry : hashMap.entrySet()) {
// your code
}