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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)

JAXB Unmarshall to List

I am trying to unmarshall this XML to Java objects, a Customer object containing a List of EmailAdresses.
<customer>
<emailAddresses>janed#example.com</emailAddresses>
<emailAddresses>jdoe#example.org</emailAddresses>
</customer>
Having an issue with the list, I get the correct number of list items (2), but the value of the emailAddresses tag is null
Customer.java
#XmlRootElement( name = "customer" )
public class Customer
{
private List<EmailAddress> emailAddresses;
public Customer()
{
emailAddresses = new ArrayList<EmailAddress>();
}
public List<EmailAddress> getEmailAddresses()
{
return emailAddresses;
}
public void setEmailAddresses( List<EmailAddress> emailAddresses )
{
this.emailAddresses = emailAddresses;
}
}
EmailAddress.java
public class EmailAddress
{
private String emailAddresses;
public String getEmailAddresses()
{
return emailAddresses;
}
public void setEmailAddresses( String emailAddresses )
{
this.emailAddresses = emailAddresses;
}
}
Failing Unit Test
#Test
public void shouldDeserialiseCusomerXMLToObject() throws JAXBException
{
String xml = "<customer>"
+ " <emailAddresses>janed#example.com</emailAddresses>"
+ " <emailAddresses>jdoe#example.org</emailAddresses>"
+ "</customer>";
JAXBContext jaxbContext = JAXBContext.newInstance( Customer.class );
Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
StringReader reader = new StringReader( xml );
Customer msg = ( Customer ) jaxbUnmarshaller.unmarshal( reader );
// This passes, I have 2 emailAddresses
assertEquals( 2, msg.getEmailAddresses().size() );
// This fails, I have a null pointer instead of the email address
assertEquals( "janed#example.com", msg.getEmailAddresses().get( 0 ).getEmailAddresses() );
}

The emailAddresses field of EmailAddress is by default treated as a subelement, expecting the XML to be:
<customer>
<emailAddresses>
<emailAddresses>janed#example.com</emailAddresses>
</emailAddresses>
<emailAddresses>
<emailAddresses>jdoe#example.org</emailAddresses>
</emailAddresses>
</customer>
Since your outer <emailAddresses> element doesn't contain an inner <emailAddresses> element, the field is never assigned.
You want the emailAddresses field of EmailAddress to be the value of the (outer) <emailAddresses> element, so you have to tell JAXB that, by specifying the #XmlValue annotation:
#XmlValue
public String getEmailAddresses()
{
return emailAddresses;
}
The #XmlValue annotation is especially useful when combined with #XmlAttribute, to support XML like this:
<Person sex="male" age="25">John Doe</Person>
Where class would then be:
public class Person {
public enum Sex {
#XmlEnumValue("male") MALE,
#XmlEnumValue("female") FEMALE,
}
#XmlAttribute
private Sex sex;
#XmlAttribute
private int age;
#Value
private String name;
}

You have a level too many of email addresses.
If you should change the list of email addresses to a list of strings, like
#XmlRootElement( name = "customer" )
public class Customer
{
private List<String> emailAddresses;
public Customer()
{
emailAddresses = new ArrayList<String>();
}
public List<String> getEmailAddresses()
{
return emailAddresses;
}
public void setEmailAddresses( List<String> emailAddresses )
{
this.emailAddresses = emailAddresses;
}
}

Correct way to parse XML using Simple Framework

I'm using Simple framework to deserialize an xml on my android app .
The issue is on a portion of the xml because I can get the objects of the other portions of it .
Here is the part of the xml that I struggle with :
<webtv name="channelname" date="2014-10-31">
<config>
<pathVideo extension="mp4">http://vodflash.channelname.com/tv_conn/1/country/</pathVideo>
<pathBigImage extension="jpg">http://vodflash.channelname.com/tv_conn/1/country/pic/320x180/</pathBigImage>
<pathImage extension="jpg">http://vodflash.channelname.com/tv_conn/1/country/pic/160x90/</pathImage>
<pays>GB;IE</pays>
</config>
Here is my XmlMapper class :
#Root(name="webtv", strict = false)
public class XmlModelMapper {
public ConfigObject getConfigObjects() {
return configObject;
}
#Element(name="config")
public ConfigObject configObject = new ConfigObject();
#ElementList(name = "itemList")
private List<Videos> itemList = new ArrayList<Videos>();
public List<Videos> getItemList() {
return itemList;
}
#ElementList(name = "chaineList")
private List<Chaine> chaineList = new ArrayList<Chaine>();
public List<Chaine> getChaineList() {
return chaineList;
}
}
If I change my mapper class to this :
#Root(name="webtv", strict = false)
public class XmlModelMapper {
public List<ConfigObject> getConfigObjects() {
return configObject;
}
//change is here using a list not an object
#ElementList(name="config")
public List<ConfigObject> configObjects = new ArrayList<ConfigObject>();
#ElementList(name = "itemList")
private List<Videos> itemList = new ArrayList<Videos>();
public List<Videos> getItemList() {
return itemList;
}
#ElementList(name = "chaineList")
private List<Chaine> chaineList = new ArrayList<Chaine>();
public List<Chaine> getChaineList() {
return chaineList;
}
}
and the log the size of the List I get 4 which is correct , but how to get each object in a distinct way including the extension (attribute)
Please help me solving this issue .
Thanks

#ElementList(name="config")
public List<ConfigObject> configObjects = new ArrayList<ConfigObject>();
This wont match with your xml listed above. While the #Element-based solution (example 1) will create a proper config-tag, the list adds another "list-tag"; here's an example:
<config> <!-- This is the list's tag, wrapping all elements -->
<config> <!-- This is the actual element's tag -->
<pathVideo extension="mp4">http://video.com</pathVideo>
<pathBigImage extension="jpg">http://bigimg.com</pathBigImage>
<pathImage extension="jpg">http://image.com</pathImage>
<pays>GB;IE</pays>
</config>
<!-- some more <config>...</config> -->
</config>
The solution: Use athe inline list - those don't have the "list-tag".
#ElementList(name = "config", inline = true, entry = "config")
public List<ConfigObject> configObjects = new ArrayList<>();
For the sake of completeness, here are my classes used for testing:
class Chaine { /* empty - enough for testing */ }
class Videos { /* empty - enough for testing */ }
#Root
public class ConfigObject
{
#Element(name = "pathVideo")
private PathConfig video;
#Element(name = "pathBigImage")
private PathConfig bigImage;
#Element(name = "pathImage")
private PathConfig image;
#Element(name = "pays")
private String pays;
// ...
}
#Root
public class PathConfig
{
#Attribute(name = "extension")
private String extension;
#Text
private String path;
// ...
}

Solved my issue and learned alot about simple framework which is great and light weight , but I prefer ollo's answer
Please discard ormlite annotations
My classes :
#Root(name="webtv", strict = false)
public class XmlModelMapper {
public ConfigObject getConfigObject() {
return configObject;
}
#Element(name="config")
public ConfigObject configObject = new ConfigObject();
//rest of the elements
...
}
and
#Root(name = "config" , strict = false)
public class ConfigObject {
#Element
PathVideo pathVideo;
#Element
PathImage pathImage;
#Element
PathBigImage pathBigImage ;
//rest of the elements
}
and
#Root(name = "pathImage")
#DatabaseTable(tableName = "imageconfig")
public class PathImage {
#DatabaseField(generatedId = true)
Integer id ;
#Attribute
#DatabaseField
String extension;
#Text
#DatabaseField
String pathImage;
//rest of the elements...
}
and
#Root(name = "pathVideo")
#DatabaseTable(tableName = "videoconfig")
public class PathVideo {
#DatabaseField(generatedId = true)
Integer id ;
#Attribute
#DatabaseField
String extension;
#Text
#DatabaseField
String pathVideo;
}
and finally
#Root(name = "pathBigImage")
#DatabaseTable(tableName = "bigimageconfig")
public class PathBigImage {
#DatabaseField(generatedId = true)
Integer id ;
#Attribute
#DatabaseField
String extension;
#Text
#DatabaseField
String pathBigImage;
//rest of the elements...
}

Deserialize XML elements to different types, based on attribute

I have an XML document with many Entity elements, which each have an attribute of either type="foo" or type="bar". See this sample:
<RootNode>
<Entities>
<Entity type="foo">
<Price>1</Price>
</Entity>
<Entity type="bar">
<URL>www.google.co.uk</URL>
</Entity>
<Entity type="foo">
<Price>77</Price>
</Entity>
</Entities>
</RootNode>
I need a way to tell Simple to deserialize the Entity elements with type="foo" into a List<FooEntity> and the elements with type="bar" into a List<BarEntity>.
How can I do this?
Here is the code I currently have if you want to play around with it:
public class App {
public static void main(String[] args) throws Exception {
Reader r = Files.newBufferedReader(
Paths.get("/path/to/file.xml"),
Charset.defaultCharset()
);
Serializer serializer = new Persister();
RootNode root = serializer.read(RootNode.class, r);
System.out.println(root.getFooEntities().size());
System.out.println(root.getBarEntities().size());
}
}
#Root(name = "RootNode")
class RootNode {
// TODO: What annotations to put here?
private List<FooEntity> fooEntities;
// TODO: What annotations to put here?
private List<BarEntity> barEntities;
public List<FooEntity> getFooEntities() { return fooEntities; }
public List<BarEntity> getBarEntities() { return barEntities; }
}
class FooEntity {
#Element(name = "URL")
private String url;
}
class BarEntity {
#Element(name = "Price")
private int price;
}

Now the real problem ...
// TODO: What annotations to put here?
private List<BarEntity> barEntities;
My answer: none! Or at least, it doesn't matter!
Attributes like type here are just strings and can't make any decisions. But there's another nice way:
Implement a Converter for RootNode which does the decision
Use a Serializer to do the actual work of deserializing each entity.
I made some modifications to your classes, but nothing spectacular has been changed. The toString()-method is for testing only - implement as you need it.
Class FooEntity
#Root(name = "Entity")
public class FooEntity
{
#Attribute(name = "type")
private String type;
#Element(name = "Price")
private int price;
/*
* NOTE: A default ctor is required - visibile doesn't matter
*/
#Override
public String toString()
{
return "FooEntity{" + "price=" + price + '}';
}
}
Class BarEntity
#Root(name = "Entity")
public class BarEntity
{
#Attribute(name = "type")
private String type;
#Element(name = "URL")
private String url;
/*
* NOTE: A default ctor is required - visibile doesn't matter
*/
#Override
public String toString()
{
return "BarEntity{" + "url=" + url + '}';
}
}
Class RootNode
#Root(name = "RootNode")
#Convert(RootNodeConverter.class) // <--- Important!
class RootNode
{
private List<FooEntity> fooEntities;
private List<BarEntity> barEntities;
public RootNode()
{
// This has to be done somewhere ...
this.fooEntities = new ArrayList<>();
this.barEntities = new ArrayList<>();
}
public List<FooEntity> getFooEntities()
{
return fooEntities;
}
public List<BarEntity> getBarEntities()
{
return barEntities;
}
#Override
public String toString()
{
return "RootNode{" + "fooEntities=" + fooEntities + ", barEntities=" + barEntities + '}';
}
}
And finally the Converter-implementation:
Class RootNodeConverter
public class RootNodeConverter implements Converter<RootNode>
{
#Override
public RootNode read(InputNode node) throws Exception
{
RootNode root = new RootNode();
final InputNode entities = node.getNext("Entities");
InputNode child;
while( ( child = entities.getNext() ) != null )
{
if( child.getName().equals("Entity") == false )
{
continue; // Not an Entity
}
final Serializer ser = new Persister();
switch(child.getAttribute("type").getValue())
{
case "foo":
root.getFooEntities().add(ser.read(FooEntity.class, child));
break;
case "bar":
root.getBarEntities().add(ser.read(BarEntity.class, child));
break;
default:
// Not a Foo nor a Bar - what now!?
break;
}
}
return root;
}
#Override
public void write(OutputNode node, RootNode value) throws Exception
{
throw new UnsupportedOperationException("Not implemented yet!");
}
}
There are some things to optimize, eg. add a root.addBar(ser.read(BarEntity.class, child)) or errorhandling in general.
Btw. instead of two lists, you can maintain a single one (if relevant). Just make a superclass for the entities. You can move the type-attribute to there too.
Usage
Here's an example how to use:
final String input = "<RootNode>\n"
+ " <Entities>\n"
+ " <Entity type=\"foo\">\n"
+ " <Price>1</Price>\n"
+ " </Entity>\n"
+ "\n"
+ " <Entity type=\"bar\">\n"
+ " <URL>www.google.co.uk</URL>\n"
+ " </Entity>\n"
+ "\n"
+ " <Entity type=\"foo\">\n"
+ " <Price>77</Price>\n"
+ " </Entity>\n"
+ " </Entities>\n"
+ "</RootNode>";
final Serializer ser = new Persister(new AnnotationStrategy()); // <-- Note the strategy!
RootNode root = ser.read(RootNode.class, input);
System.out.println(root);
Nothing really spectacular here too ...
Output:
RootNode{fooEntities=[FooEntity{price=1}, FooEntity{price=77}], barEntities=[BarEntity{url=www.google.co.uk}]}

XML to java Object conversion using simpleframework

I am converting xml file to java object using simpleframework. I am using generics since my xml's internal nodes gets changing. But simpleframework throws an error while converting. Here is my sample code:
#Root(name = "searchresult", strict = false)
public class ResponseVO<T>
{
#ElementList(entry = "document", inline = true)
public List<T> elementVOList = new ArrayList<T>();
public List<T> getElementsVOList()
{
return elementVOList;
}
public void setElementsVOList(List<T>list)
{
elementVOList = list;
}
}
ResponseVO is container for various other VOs as below:
#Root(name = "document", strict = false)
public class Projects_Display_VO
{
#Element(name = "projectname")
private String projectName;
#Attribute(name = "id")
private int tmpid;
public int getTmpid()
{
return tmpid;
}
public void setTmpid(int tmpid)
{
this.tmpid = tmpid;
}
/**
* ProjectId
*/
#Element(name = "projectid")
private String projectID;
public String getProjectName()
{
return projectName;
}
public void setProjectName(String projectName)
{
this.projectName = projectName;
}
public int getProjectID()
{
return Integer.parseInt(projectID);
}
public void setProjectID(String projectID)
{
this.projectID = projectID;
}
}
And the XML file is as below:
<searchresult>
<query>id:(PROJ2 PROJ6)</query>
<document id="0">
<projectid>2</projectid>
<projectname>Redundant Demo Project</projectname>
<doctype>Projects</doctype>
<summary>||Demo Project</summary>
<title>Redundant Demo Project</title>
</document>
<document id="1">
<projectid>6</projectid>
<projectname>Redundant Demo Project2</projectname>
<doctype>Projects</doctype>
<summary>||Main terminal links.</summary>
<title>Terminal 5 Project</title>
</document>
</searchresult>
The code for conversion is as bellow:
ResponseVO<Projects_Display_VO> resp = (ResponseVO<Projects_Display_VO>) SerializationUtil.deserialize(ResponseVO.class, reader);
Here i am using serializer from simpleframework. But it throws following error
Exception::Attribute 'id' does not have a match in class java.lang.Object at line 5
org.simpleframework.xml.core.AttributeException: Attribute 'id' does not have a match in class java.lang.Object at line 5
at org.simpleframework.xml.core.Composite.readAttribute(Composite.java:555)
at org.simpleframework.xml.core.Composite.readAttributes(Composite.java:474)
at org.simpleframework.xml.core.Composite.readSection(Composite.java:387)
I dont know whats going wrong here.A it works fine without generics.
Thanks in advance

This is caused by erasure, T is not available at runtime. Java does not allow it.